SEC Form PRER14A filed by HOOKIPA Pharma Inc.

You are cordially invited to attend a special meeting of stockholders (the “Special Meeting”) of HOOKIPA Pharma Inc., a Delaware corporation (the “Company,” “HOOKIPA,” “we,” “us,” or “our”), to be held on    , 2025, at 10:00 a.m. Eastern Time.

The Special Meeting will be held in a virtual-only meeting format at www.virtualshareholdermeeting.com/HOOK2025SM. We believe hosting a virtual meeting enables participation by more of our stockholders, while lowering the cost of conducting the meeting. Stockholders attending the virtual meeting will be afforded the same rights and opportunities to participate as they would at an in-person meeting. We encourage you to attend online and participate. We recommend that you log in a few minutes before 10:00 a.m., Eastern Time, on    , 2025 to ensure you are logged in when the Special Meeting starts. You will not be able to attend the Special Meeting in person.

The Special Meeting will be held for the following purposes:

These items of business are more fully described in the proxy statement accompanying this notice. The record date for the Special Meeting is June 17, 2025. Only stockholders of record at the close of business on that date are entitled to notice of and may vote at the Special Meeting or any adjournment thereof.

The Board is seeking stockholder approval of the Asset Sale because we are a Delaware corporation and the Asset Sale may constitute the sale of “substantially all” of our property and assets under Section 271 of the General Corporation Law of the State of Delaware (the “DGCL”). Section 271 of the DGCL requires that a Delaware corporation obtain the approval of the holders of a majority of the corporation’s outstanding stock entitled to vote thereon for the sale of “all or substantially all of its property and assets.” Additionally, approval of the Asset Sale by holders of a majority in voting power of our outstanding stock is a closing condition under the Asset Purchase Agreement. The proposals to approve the Asset Sale pursuant to the Asset Purchase Agreement and to approve the subsequent Dissolution require the affirmative vote of the holders of a majority of the outstanding shares of our common stock. Therefore, it is very important that your shares be represented and voted at the Special Meeting.

The approval of the Asset Sale Proposal is not conditioned upon stockholders approving the Dissolution Proposal, but the approval of the Dissolution Proposal is conditioned on stockholders approving the Asset Sale Proposal. The effectiveness of the Dissolution is conditioned upon the consummation of the Asset Sale. The Adjournment Proposal is not conditioned upon the approval of any other proposal set forth in the proxy statement. Stockholders do not have dissenters’ rights of appraisal in connection with the Asset Sale or the Dissolution.

If the stockholders approve the Asset Sale and the Dissolution, the Company intends to file a Certificate of Dissolution (the “Certificate of Dissolution”) with the Delaware Secretary of State as soon as practicable following the closing of the Asset Sale and the completion of the transfer plan under the Asset Purchase Agreement (the “Transfer Plan”). Upon the Company’s filing of a Certificate of Dissolution with the Delaware Secretary of State, the winding up and liquidation of the Company pursuant to the Plan of Dissolution will commence. On the date the Company files a Certificate of Dissolution with the Delaware Secretary of State, the Company will close its stock transfer books, after which it will not be possible for stockholders to trade our stock, which is referred to herein as the “Final Record Date”.

After filing the Certificate of Dissolution, the Company plans to make distributions to the stockholders, subject to a contingency reserve for remaining costs and liabilities including those stemming from the Asset Purchase Agreement, of available proceeds, including from the Asset Sale, if any. The amount and timing of any distributions to stockholders will be determined by the Board in its discretion, as described in the Plan of Dissolution. However, there can be no assurance as to the timing and amount of distributions to our stockholders, if any, because there are many factors, some of which are outside of our control, that could affect our ability to make such distributions.

The enclosed proxy statement provides you with detailed information about the Special Meeting and the proposed transactions. In particular, please review the matters referred to under “Risk Factors” starting on page 25 for a discussion of the risks related to the Asset Sale and the Dissolution. We encourage you to read the proxy statement and all annexes thereto carefully and in their entirety. You may also obtain additional information about us from documents we have filed with the Securities and Exchange Commission, which are available without charge through the Securities and Exchange Commission’s website at www.sec.gov.

Your vote is extremely important, regardless of the number of shares you own. Whether or not you plan to attend the Special Meeting, we ask that you promptly sign, date and return the enclosed proxy card in the envelope provided, or submit your proxy by telephone or over the internet (if those options are available to you) in accordance with the instructions on the enclosed proxy card. If your shares of common stock are held in “street name” by your broker, bank or other nominee, you should instruct your broker, bank or other nominee on how to vote your shares of common stock using the instructions provided by your broker, bank or other nominee.

The Company’s Board has unanimously approved the Asset Sale pursuant to the Asset Purchase Agreement and the Dissolution and the Plan of Dissolution, in each case as being in the best interests of the Company and its stockholders. The Board recommends that you vote “FOR” the Asset Sale Proposal, “FOR” the Dissolution Proposal and “FOR” the Adjournment Proposal.

Neither the United States Securities and Exchange Commission nor any state securities commission has approved or disapproved of the Asset Sale or the Dissolution, passed upon the merits of the Asset Sale or the Dissolution or passed upon the adequacy or accuracy of the information contained in this proxy statement and any documents incorporated by reference. Any representation to the contrary is a criminal offense.

The accompanying proxy statement is dated    , 2025, and, together with the enclosed form of proxy card, is first being mailed to our stockholders on or about such date.

We intend to mail these proxy materials on or about    , 2025 to all stockholders of record entitled to vote at the Special Meeting. These proxy materials are available on the investor relations page of our website at www.hookipapharma.com. The information contained on, or accessible through, the websites referenced in this proxy statement is not incorporated by reference into this proxy statement.

A complete list of the stockholders entitled to vote at the Special Meeting will be available for examination during regular business hours for the ten (10) days prior to the Special Meeting by request. You may email us at [email protected] to coordinate arrangements to view the stockholder list.

WHETHER OR NOT YOU PLAN TO ATTEND THE SPECIAL MEETING, WE ENCOURAGE YOU TO SUBMIT YOUR PROXY AS PROMPTLY AS POSSIBLE: (1) BY TELEPHONE; (2) THROUGH THE INTERNET; OR (3) BY SIGNING AND DATING THE ENCLOSED PROXY CARD AND RETURNING IT IN THE POSTAGE-PAID ENVELOPE PROVIDED. You may revoke your proxy or change your vote at any time before it is voted at the Special Meeting.

If you hold your shares of common stock in “street name,” you should instruct your bank, broker or other nominee how to vote your shares of common stock in accordance with the voting instruction form that you will receive from your bank, broker or other nominee. Your broker or other agent cannot vote on any of the proposals, including the Asset Sale Proposal and the Dissolution Proposal, without your instructions.

If you are a stockholder of record, voting virtually at the Special Meeting will revoke any proxy that you previously submitted. If you hold your shares of common stock through a bank, broker or other nominee, you must obtain a “legal proxy” in order to vote virtually at the Special Meeting.

If you fail to (1) sign and return your proxy card, (2) grant your proxy electronically over the Internet or by telephone or (3) vote virtually at the Special Meeting, your shares of common stock will not be counted for purposes of determining whether a quorum is present at the Special Meeting and will have the same effect as a vote “AGAINST” the Asset Sale Proposal and the Dissolution Proposal.

You should carefully read and consider this entire proxy statement and the annexes to this proxy statement, along with all of the documents incorporated by reference into this proxy statement, as they contain important information about, among other things, the Asset Sale and the Dissolution and how both affect you.

The following questions and answers are intended to address briefly some commonly asked questions regarding the Asset Sale, the Asset Purchase Agreement, the Dissolution, and the Plan of Dissolution and the Special Meeting. These questions and answers may not address all questions that may be important to you as a stockholder of the Company. Please refer to the “Summary of Terms” beginning on page 1 and the more detailed information contained elsewhere in this proxy statement, the annexes to this proxy statement and the documents referred to or incorporated by reference in this proxy statement. See “Where You Can Find Additional Information” beginning on page 73.

The procedures for voting are described below.

This proxy statement, and the documents to which we refer you in this proxy statement, contain “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”), and Section 21E of the Exchange Act. Forward-looking statements are often identified by the use of words such as, but not limited to, “believes,” “estimates,” “anticipates,” “continues,” “contemplates,” “expects,” “may,” “will,” “could,” “should” or “would” and other similar words or phrases. These statements, which are based on information currently available to us, are not guarantees of future performance and may involve risks and uncertainties that could cause our actual growth, results of operations, performance and business prospects, and opportunities to materially differ from those expressed in, or implied by, these statements. These forward-looking statements speak only as of the date on which the statements were made and, except as required by applicable securities laws, we expressly disclaim any obligation to release publicly any updates or revisions to any forward-looking statement included in this proxy statement or elsewhere. In addition to other factors and matters contained or incorporated in this proxy statement, these statements are subject to risks, uncertainties, and other factors, including, among others:

The foregoing list of factors is not exclusive. Additionally, we are subject to risks and uncertainties and other factors detailed in our most recent annual report on Form 10-K for the fiscal year ended December 31, 2024, filed with the SEC on February 28, 2025, as supplemented by our Quarterly Reports on Form 10-Q, which should be read in conjunction with this proxy statement. See “Where You Can Find Additional Information” on page 73. In light of the significant uncertainties inherent in forward-looking statements, readers should not place undue reliance on forward-looking statements. All subsequent written and oral forward-looking statements concerning the Company or other matters attributable to the Company or any person acting on our behalf are expressly qualified in their entirety by the cautionary statements above. The Company does not undertake any obligation to update any forward-looking statement, whether written or oral, relating to the matters discussed in this document.

You should carefully consider the risk factors described below and those risk factors generally associated with our business contained in our Annual Report on Form 10-K for the year ended December 31, 2024 and our subsequent U.S. Securities and Exchange Commission (the “SEC”) filings, along with other information provided to you in this proxy statement, in deciding how to vote on the proposals to approve the Asset Sale and the Dissolution. See “Where You Can Find Additional Information” beginning on page 73. The special risk considerations described below are not the only ones facing us. Additional considerations not presently known to us or that we currently believe are immaterial may also impair our business operations. If any of the following special risk considerations actually occurs, our business, financial condition or results of operations could be materially adversely affected, the market price of our common stock may decline, and you may lose all or part of your investment.

We cannot provide assurances that the Asset Sale will be completed. The closing of the Asset Sale is subject to a number of conditions, including but not limited to our obtaining stockholder approval of the Asset Purchase Agreement and providing necessary third-party consents and approvals in order to sell the Assets. In addition, if the Asset Sale is not completed, the market price for our common stock may decline.

Our announcement of the Asset Sale may cause employees working for us to become concerned about the future of the business and lose focus or seek other employment.

In addition, if the Asset Sale is not completed, our directors, executive officers and other employees will have expended extensive time and effort and experienced significant distractions from their work during the pendency of the Asset Sale and we will have incurred significant third party transaction costs, in each case, without any commensurate benefit, which may have a material and adverse effect on our stock price and results of operations.

We expect to receive aggregate net proceeds of approximately $7.6 million, after payment of transaction and other related expenses, applicable taxes (if any) and sublicense expenses, assuming the entire $10.0 million purchase price is paid upon successful completion of the Transfer Plan. If Gilead disputes the completion of a phase of the Transfer Plan, we will not receive the cash consideration for such phase until we and Gilead agree that such phase has been completed or the dispute is resolved in our favor. In addition, if Gilead successfully asserts claims for indemnification pursuant to the indemnification provisions of the Asset Purchase Agreement, the amount of net proceeds is subject to further reduction. We may also have unforeseen liabilities and expenses that must be satisfied from the after-tax net proceeds of the Asset Sale. As a result, the amount of the net proceeds from the Asset Sale is subject to substantial uncertainty, and it is possible that the net proceeds from the Asset Sale will be materially less than we expect.

The Asset Purchase Agreement requires that we pay Gilead’s out-of-pocket transaction expenses up to $400,000 if certain events specified in the Asset Purchase Agreement occur, including in the event that we pursue a Superior Proposal. The amount of this expense reimbursement may have the effect of causing other potential third-party buyers to not submit a proposal to acquire us or our subsidiaries or our assets at a higher price or to enter into a more favorable alternative transaction.

The Asset Purchase Agreement contains provisions that make it more difficult for us to sell the Assets to any party other than Gilead or to sell any other of our assets prior to the closing of the Asset Sale. These provisions include the prohibition on our ability to solicit competing proposals, the requirement that we pay Gilead’s out-of-pocket transaction expenses if the Asset Purchase Agreement is terminated in specified circumstances and Gilead’s right to be advised of competing proposals and to submit revised proposals for consideration. See “The Asset Purchase Agreement — Restrictions on Solicitation of Other Offers” and “The Asset Purchase Agreement —

Expense Reimbursement”. These provisions could discourage a third party that might have an interest in acquiring all of or a significant part of the Company from considering or proposing an alternative transaction, and could make it more difficult for us to complete an alternative business combination transaction with another party.

Under the Asset Purchase Agreement, the Sellers have agreed to indemnify Gilead for a breaches of certain fundamental representations, warranties and covenants made by the Sellers in the Asset Purchase Agreement, for the transfer of any employees by operation of law, for certain taxes, for fraud by the Sellers or any of their representatives, employee related liabilities, the dissolution, liquidation, winding up or insolvency of either Seller and any Excluded Asset or Excluded Liability. Significant indemnification claims by Gilead could reduce the amount of net proceeds ultimately distributed to stockholders following the Asset Sale and expose us to contingent liabilities. See “The Asset Purchase Agreement–Indemnification” beginning on page 55.

The Board is not required to and did not obtain a fairness opinion in connection with the Asset Sale. Stockholders are therefore relying on the judgment of the Board and will not have assurance from an independent source that the consideration Gilead is paying for the Assets is fair to the Company from a financial point of view.

You should be aware of interests of, and the benefits available to, our directors and executive officers when considering the recommendation of our Board on the Asset Sale Proposal and the Dissolution Proposal. Our directors and executive officers may have interests in the Asset Sale and the Dissolution that may be in addition to, or different from, their interests as stockholders. These interests include the fact that the vesting of 178,570 restricted stock units and 32,864 options issued and unvested held by certain of our officers and directors that will be accelerated, pursuant to the terms of our Equity Plans. Our directors and executive officers will also retain the right to continued indemnification and insurance coverage for acts or omissions occurring prior to the Asset Sale and arising out of the fact that such person was a director or officer of the Company prior to the Asset Sale. For additional information regarding these matters, see “The Asset Sale (Proposal No. 1) — Interests of Our Directors and Executive Officers in the Asset Sale” beginning on page 44.

We may be subject to securities class action litigation in connection with the Asset Sale. Securities litigation against us could result in substantial costs and divert our management’s attention from closing the Asset Sale, which could harm our business and increase our expenses, which could decrease the amount available for distribution to our stockholders.

If our stockholders do not approve the Dissolution, we would have to continue our business operations from a difficult position, in light of our announced intent to dissolve and liquidate. We have ceased pursuing further preclinical programs into development outside of our Programs. Prospective employees, and other third parties may refuse to form relationships or conduct business with us if they do not believe we will continue to operate as a going concern. We also expect our common stock to be delisted from Nasdaq if stockholders approve the Asset Sale Proposal and Dissolution Proposal at the Special Meeting, following which time there may not be a liquid trading market for our common stock.

If the Asset Sale is approved, we expect to receive net proceeds of approximately $7.6 million, after payment of transaction and other related expenses, applicable taxes (if any) and sublicense expenses, assuming the entire $10.0 million purchase price is paid upon successful completion of the Transfer Plan. If Gilead disputes the

completion of a phase of the Transfer Plan, we will not receive the cash consideration for such phase until we and Gilead agree that such phase has been completed or the dispute is resolved in our favor. In addition, under the Asset Purchase Agreement, we are not permitted to file a Certificate of Dissolution until all phases of the Transfer Plan are completed. If Gilead disputes the completion of any step in the Transfer Plan and resolution of that dispute is not in our favor, and if Gilead does not waive the requirement that such phase of the Transfer Plan be completed before we are permitted to file a Certificate of Dissolution, we will be unable to dissolve or make any liquidating distributions to our stockholders, even if the Dissolution Proposal is approved. Assuming the Dissolution is approved by stockholders, we plan to make distributions to the stockholders, subject to a contingency reserve for remaining costs and liabilities including those stemming from the Asset Purchase Agreement, of available proceeds, including from the Asset Sale, if any, after the filing of a Certificate of Dissolution with the Delaware Secretary of State. The amount and timing of any distributions to stockholders will be determined by the Board in its discretion. On the bases described in this proxy statement, the Board anticipates that any distribution to stockholders will not occur any earlier than the date that is three years after the filing of the Certificate of Dissolution and may be approximately $1.28 to $1.72 per share of common stock and Class A common stock (based on 9,799,053 shares of common stock and 2,399,517 shares of Class A common stock outstanding on the record date), after taking into account currently known and estimated expenses and liabilities, and assuming the entire $10.0 million purchase price in the Asset Sale is paid to the Sellers and no indemnification claims are made under the Asset Purchase Agreement. However, there can be no assurance as to the timing and amount of distributions, if any, to our stockholders because there are many factors, some of which are outside of our control, that could affect our ability to make such distributions. Those determinations depend on a variety of factors, including, but not limited to, the amount we will be required to pay to satisfy unknown or contingent liabilities in the future; the cost of operating our business through the date of our final dissolution; inaccuracies in the cost estimates to resolve currently known contingent liabilities; general business and economic conditions; and other matters.

In addition, we will continue to incur claims, liabilities and expenses from operations (such as operating costs, salaries, directors’ and officers’ insurance, payroll and local taxes, legal and accounting fees and miscellaneous office expenses) as we seek to close the Asset Sale and effect the Dissolution. Our estimates regarding our expense levels may be inaccurate. Any unexpected claims, liabilities or expenses that arise between the date of filing of this proxy statement and the liquidation and final dissolution of the Company or any claims, liabilities or expenses that exceed our estimates could leave us with less cash than is necessary to pay liabilities and expenses and would likely reduce the amount of cash available for ultimate distribution to our stockholders.

For the foregoing reasons, there can be no assurance as to the timing and amount of distributions to our stockholders; provided that the Company intends to complete the distribution of all of its properties and assets to its stockholders as described in the Plan of Dissolution as soon as practicable following the filing of the Certificate of Dissolution with the Delaware Secretary of State and in any event on or before the tenth anniversary of such filing.

Even if the Dissolution Proposal is approved by our stockholders, the Board has reserved the right to abandon the Dissolution or modify or delay implementation of the Plan of Dissolution. Although the Board has no present intention to pursue any alternative to the Plan of Dissolution, the Board may conclude either that its fiduciary obligations require it to pursue business opportunities that present themselves or that abandoning the Dissolution is otherwise in our best interests and the best interests of our stockholders. If the Board elects to pursue any alternative to the Dissolution, the value of our common stock may decline.

If the Dissolution is approved by our stockholders, we intend to file a Certificate of Dissolution with the Delaware Secretary of State to dissolve the Company. Pursuant to the DGCL, the Company will continue to exist for a minimum of three years after its dissolution becomes effective for the purpose of prosecuting and defending suits against the Company and enabling the Company and our subsidiary to close their business, to dispose of their property, to discharge their liabilities and to distribute to stockholders any remaining assets. If a court holds at any time that we have failed to make adequate provision for our expenses and liabilities in the Dissolution or if the

amount ultimately required to be paid in respect of such liabilities exceeds the amount available from our contingency reserve, our creditors could seek an injunction against the making of distributions on the grounds that the amounts to be distributed are needed to provide for the payment of our expenses and liabilities. Any such action could delay or substantially diminish the amount of any cash distributions to stockholders. If we fail to create an adequate contingency reserve for payment of our expenses and liabilities, creditors could assert claims against each stockholder receiving a distribution for the payment of any shortfall, up to the amounts previously received by the stockholder in distributions from us. In such event, a stockholder could be required to return all distributions previously made to such stockholder pursuant to the Plan of Dissolution and could receive nothing from us under the Plan of Dissolution. Moreover, in the event that a stockholder has paid taxes on amounts previously received by the stockholder, a repayment of all or a portion of such amount could result in a stockholder incurring a net tax cost if the stockholder’s repayment of an amount previously distributed does not cause a commensurate reduction in taxes payable. The Board is not required to obtain a solvency opinion as a condition to authorizing a liquidating distribution and we cannot assure you that the contingency reserve established by us will be adequate to cover all expenses and liabilities.

We have not requested a ruling from the Internal Revenue Service (“IRS”) with respect to the anticipated tax consequences of the Dissolution, and we will not seek an opinion of counsel with respect to the anticipated tax consequences of any liquidating distributions. If any of the anticipated tax consequences described in this proxy statement proves to be incorrect, the result could be increased taxation at the corporate and/or stockholder level, thus reducing the benefit to our stockholders and us from the liquidation and distributions. Tax considerations applicable to particular stockholders may vary with and be contingent upon the stockholder’s individual circumstances.

For U.S. federal income tax purposes, distributions made pursuant to the Plan of Dissolution are intended to be treated as received by a stockholder in exchange for the stockholder’s shares of our common stock in complete liquidation of the company. As a result, it is intended that stockholders will recognize gain or loss equal to the difference between (a) the sum of the amount of cash distributed to them and the aggregate fair market value of any property distributed to them, and (b) their tax basis in their shares of common stock. A stockholder’s tax basis in its shares generally will equal the stockholder’s cost to acquire the common stock, although, depending on various circumstances, that general rule may not apply in a particular case. Any loss generally will be recognized only when the final distribution from us has been received, which may be more than three years after our dissolution, and only if the stockholder is still the owner of the shares of common stock. The deductibility of capital losses is subject to limitations. You should consult your tax advisor as to the particular tax consequences of the Dissolution to you, including the applicability of any U.S. federal, state, and local and non-U.S. tax laws.

The interests of our stockholders in a liquidating trust set up by us under the Plan of Dissolution would not be transferable, which could adversely affect your ability to realize the value of such interests. In addition, as stockholders will be deemed to have received a liquidating distribution equal to their pro rata share of the value of the net assets distributed to an entity which is treated as a liquidating trust for tax purposes, the distribution of non-transferable interests could result in tax liability to the interest holders without such holders being readily able to realize the value of such interest to pay such taxes or otherwise.

Our Board may at any time turn our management over to a third party to complete the liquidation of our remaining assets and distribute the available proceeds to our stockholders, and some or all of our directors may resign from the Board at or before that time. If management is turned over to a third party and all of our directors resign from our Board, the third party would have sole control over the liquidation process, including the sale or distribution of any remaining assets under the Plan of Dissolution.

We intend to notify Nasdaq of our intent to withdraw our common stock from listing on the Nasdaq Capital Market and thereafter file an application on Form 25 to notify the SEC of the withdrawal of our common stock from listing on the Nasdaq Capital Market as soon as practicable following the Special Meeting. The delisting of our common stock will be effective 10 days after we file such an application on Form 25, after which it will not be possible for stockholders to publicly trade our stock on the Nasdaq Capital Market, and any trading in our common stock may be very limited.

On the date we file the Certificate of Dissolution with the Delaware Secretary of State, we intend to close our stock transfer books and discontinue recording transfers of our common stock, including our Non-Voting Capital Stock. Thereafter, certificates or book entries representing our common stock will not be assignable or transferable on our books except by will, intestate succession or operation of law. The proportionate interests of all of our stockholders will be fixed on the basis of their respective stock holdings at the close of business on the Final Record Date, and, after the Final Record Date, any distributions made by us will be made solely to the stockholders of record at the close of business on the Final Record Date, except as may be necessary to reflect subsequent transfers recorded on our books as a result of any assignments by will, intestate succession or operation of law.

Following the Asset Sale and through the subsequent liquidation and dissolution, we have an obligation to continue to comply with the applicable reporting requirements of the Exchange Act, even though compliance with these reporting requirements will be economically burdensome, until we are able to deregister our shares and suspend our periodic reporting obligations under the Exchange Act. We intend to file a Form 25 with the SEC to delist and deregister our common stock and a Form 15 with the SEC to suspend our public reporting obligations as soon as practicable following the Special Meeting, but until we do so we will remain a reporting issuer and will incur attendant costs relating to filing such reports with the SEC. The expenses incurred by us in complying with the applicable reporting requirements will reduce the assets available for ultimate distribution to our stockholders.

The success of the Plan of Dissolution depends in large part upon our ability to retain the services of qualified personnel who will be charged with operating the Company following the closing of the Asset Sale. The retention of qualified personnel may be particularly difficult under our current circumstances. There can be no assurance that we will be successful in retaining the services of such qualified personnel or that we will be able to retain the services of such qualified personnel for the amounts the Company is willing to pay for such services.

As soon as practicable following the Special Meeting, we intend to file a Form 15 with the SEC to suspend our reporting obligation under Section 15(d) of the Exchange Act to file current and periodic reports with the SEC. As a result, investors will have limited public information regarding the status of our business and wind-up activities following the Special Meeting.

As part of our strategic review process, and in an effort to maximize stockholder value, our Board seeks to effect the sale of substantially all of the assets of HOOKIPA. In furtherance of these efforts, our Board is presenting the Asset Purchase Agreement for approval by our stockholders at the Special Meeting. The Asset Purchase Agreement was unanimously approved by our Board of Directors, subject to stockholder approval, on May 20, 2025. A copy of the Asset Purchase Agreement is attached as Annex A to this proxy statement. A summary of certain of the features of the Asset Purchase Agreement are summarized below. All capitalized, undefined terms used herein shall have the meanings ascribed to such terms in the Asset Purchase Agreement. We encourage you to read the Asset Purchase Agreement in its entirety.

HOOKIPA is a clinical-stage biopharmaceutical company developing a new class of immunotherapeutics based on our proprietary arenavirus platform that is designed to target and amplify T cell and immune responses to fight diseases. Until recently, the Company was building a proprietary immuno-oncology pipeline utilizing our replicating technology. Additionally, the Company is developing infectious disease therapies in partnership with other companies. The Company’s Programs are being developed in a partnership with Gilead. Both Programs are in Phase 1 clinical development, though the clinical trial related to the HIV Program is in the process of being wound down. The Company’s common stock is listed on Nasdaq under the symbol “HOOK”.

Gilead, a holder of greater than five percent of our capital stock, is a biopharmaceutical company that has pursued and achieved breakthroughs in medicine for more than three decades, with the goal of creating a healthier world for all people. The company is committed to advancing innovative medicines to prevent and treat life-threatening diseases, including HIV, viral hepatitis, COVID-19, cancer and inflammation. Gilead operates in more than 35 countries worldwide, with headquarters in Foster City, California.

The following chronology summarizes the material meetings and events that led to the execution of the Asset Purchase Agreement. The following chronology does not purport to catalogue every conversation among the Board, members of the Company’s senior management or the Company’s advisors and other parties, including Gilead.

The Board and the Company’s senior management actively monitor and assess developments in the biopharmaceutical industry and are generally aware of the business activities of, and transactions involving, other companies in the biopharmaceutical industry. The Company’s senior management periodically interacts with executives from senior management of several other companies in the biopharmaceutical industry, including as part of industry conferences, and occasionally has informal conversations regarding possible strategic transactions.

In addition, on an ongoing basis, the Board and the Company’s senior management regularly evaluate options for achieving the Company’s long-term strategic goals and enhancing stockholder value in light of the business, competitive, regulatory, financing and economic environment and developments in the Company’s industry. These options have included periodic assessments of potential business combinations, collaborations or licensing transactions with other biopharmaceutical companies and the sale of the Company or certain of its assets and the consideration of whether such options would be expected to deliver superior risk-adjusted stockholder value than the Company’s standalone strategic plan. In particular, during the fourth quarter of 2023, the Board conducted a thorough review of the Company’s ongoing clinical programs.

In addition, the Company’s senior management maintains an active dialogue with its partners, including Gilead in connection with the Company’s collaboration on the HB-400 Program and HB-500 Program for the treatment of HBV and HIV, respectively, under the Collaboration Agreement. Throughout 2024 and early 2025, the Company and Gilead continued to have regular operational meetings as part of its collaboration under the Collaboration Agreement.

On January 25, 2024, the Company received written notice from F. Hoffmann-La Roche Ltd. and Hoffmann-La Roche Inc. (collectively referred to as “Roche”) of their decision to terminate the Research Collaboration and License Agreement (the “Roche Collaboration Agreement”) with the Company, dated October 18, 2022. The Roche Collaboration Agreement was entered into to (i) grant Roche an exclusive license to research, develop, manufacture and commercialize the Company’s pre-clinical HB-700 cancer program, an arenaviral immunotherapeutic for KRAS-mutated cancers, and (ii) grant Roche an option right to exclusively license for research, development manufacturing and commercialization, a second, novel arenaviral immunotherapeutic program targeting undisclosed cancer antigens. The Roche Collaboration Agreement was terminated as of April 25, 2024, and the Company regained full control of the associated intellectual property portfolio and had full collaboration and licensing rights for the HB-700 program as of such termination.

On January 29, 2024, the Company announced its decision to prioritize clinical development of HB-200 for the treatment of human papillomavirus 16 positive (“HPV16+”) head and neck cancers and Gilead-partnered programs in infectious disease and to pause development activities related to HB-300 and most of its preclinical research activities. In connection with this strategic refocus, on January 22, 2024, the Board approved a plan to reduce the Company’s workforce by 55 full-time employees, or approximately 30% of the Company’s then-current employee base and to rebalance the Company’s cost structure in alignment with the new prioritization of R&D programs, and the Company notified affected employees on January 29, 2024.

In late April 2024, the Company reached alignment on a clinical development strategy with the U.S. Food and Drug Administration with a path to potential accelerated approval of HB-200 and announced the Phase 2/3 trial design for HB-200. While HB-200 represented a significant opportunity for the Company, the Board and management identified a significant additional financing need to fund the Company’s operations based on the Company’s cash runway.

On May 23, 2024, the Company announced updated positive results from its Phase 1/2 clinical trial of HB-200 for the treatment of HPV16+ head and neck cancers, clinical data from an investigator initiated trial of neoadjuvant HB-200 plus chemotherapy for the treatment of patients with non-metastatic HPV16+ oropharyngeal cancers, and preclinical data for HB-700 designed to treat KRAS-mutated lung, colorectal, pancreatic and other cancers. However, strong data from a clinical stage oncology company on May 24, 2024 overshadowed the HB-200 update, resulting in a decline of the Company’s stock price of approximately 23.1% on May 24, 2024. As a result of the downward pressure on the Company’s stock price, the Board and management determined that it would be increasingly challenging to raise sufficient funds on a standalone basis without substantially diluting existing stockholders.

On June 18, 2024, the Board and management met and discussed recent feedback from discussions with one of the Company’s largest stockholders. Such stockholder was not supportive of providing additional financing to the Company. In light of the feedback from such stockholder, the Board discussed the Company’s budget, cash runway, anticipated data readouts, potential cost cuts and other strategic and operational matters. During such Board meeting, the Board also (i) appointed a Strategic Committee of the Board comprised of Julie O’Neill, Dr. Malte Peters and Terry Coelho (the “Strategic Committee”) to conduct a review of the Company’s operations and financials and of strategic alternatives for the Company and to provide updates to the Board on its reviews and (ii) discussed potentially engaging an investment bank to advise on the Company’s review of strategic alternatives. The Board was generally kept aware of all activities of the Strategic Committee during the course of the activities that follow, including at Board meetings and other more informal periodic updates.

On July 8, 2024, the Company announced a 1-for-10 reverse stock split of the Company’s outstanding shares of common stock in order to regain compliance with the minimum bid price requirement for the continued listing on Nasdaq.

On July 22, 2024, Joern Aldag resigned as Chief Executive Officer and a director of the Company, Reinhard Kandera resigned as Chief Financial Officer and a director of the Company and the Board appointed Dr. Malte Peters and Terry Coelho as Chief Executive Officer and Chief Financial Officer, respectively.

During July and August 2024, the Strategic Committee held several meetings. In particular they interviewed three potential financial advisors and ultimately selected Moelis & Company LLC (“Moelis”) to be the Company’s financial advisor in connection with the strategic alternative review process. In connection with the Strategic Committee’s review, the Strategic Committee reviewed preliminary forecasts for the Company’s expected cash position at various periods of time, including potential factors that may impact the cash position and the Company’s ability to extend the Company’s cash position. Among the factors noted were the headcount of the Company, the ability to monetize certain of the Company’s assets and the receipt of research grants from Austria for prior periods, which could serve as liquidity for the Company. In connection with these reviews, the Strategic Committee determined that it would be important to get prompt feedback from potentially interested parties on whether any of them were interested in a proposed transaction to be able to take steps that may be available to the Company to extend the Company’s cash position. As a result, the Strategic Committee directed the Company’s management to work with Moelis to prepare materials and information about the Company to be able to solicit interest in a potential transaction as soon as possible. Company management, with assistance from Moelis, also began to prepare a list of parties that Company management and Moelis believed would be most interested in entering into a transaction with the Company, including parties that may be interested in acquiring the Company as a whole, acquiring assets of the Company or merging their operations with the Company.

In late July 2024, the Company retained Trinity Life Sciences to complete an external commercial assessment of HB-200 and HB-700.

On August 27, 2024, each of Jan van de Winkel, Ph.D. and Timothy Reilly, Ph.D. notified the Company of his resignation as a director of the Company. In connection with such resignations, the Board appointed Julie O’Neill to serve as non-executive chair of the Board.

On September 12, 2024, the Board held a regular meeting at which they discussed the work being undertaken by the Company management. At the meeting, outside counsel to the Company reviewed with the Board the fiduciary duties of the directors that may be applicable in connection with the consideration of certain strategic transactions. At the meeting, Moelis reviewed with the Board the Company’s cash burn rate, the impact of the Company’s cash burn rate on potential transactions, a range of potential transaction alternatives that may be available, the preparation work that had been undertaken by Moelis and the Company’s management to date and a proposed timeline for evaluating interest in a potential transaction. The Board reviewed with Moelis a list of potentially interested parties that the Company and Moelis believed would be most interested in entering into a transaction with the Company, including parties that may be interested in acquiring the Company as a whole, acquiring assets of the Company or merging their operations with the Company. After discussion, the Board directed Moelis to contact the parties that had been identified to inquire about their interest in entering into a transaction with the Company.

On September 20, 2024, following authorization by the Board, the Company executed an engagement letter with Moelis to serve as a financial advisor to the Company.

Following the Company’s execution of the Moelis engagement letter on September 20, 2024, Moelis began to contact the identified parties to determine whether any were interested in a transaction with the Company, which process continued for the next several weeks. Between September and November 2024, Moelis reached out to 74 biopharmaceutical and pharmaceutical companies regarding a potential strategic transaction, including a sale, reverse merger, licensing transaction, financing transaction, spin-off or other business combination transaction. 44 initial responses were received, and non-confidential calls were held with 16 counterparties, five of whom executed confidentiality agreements, received data room access and participated in a management presentation with the Company. Trinity Life Sciences held presentations with three interested parties to discuss Trinity Life Sciences’ report summarizing its external commercial assessment on the Company’s HB-200 and HB-700 programs. As a result of this outreach, the Company received proposals from two of the parties contacted, one for a potential reverse merger transaction with a biopharmaceutical company (“Company A”) and a second for the transaction with Poolbeg Pharma plc (“Poolbeg”) described below. The other parties who signed confidentiality agreements ultimately declined to pursue a transaction with the Company primarily because they (i) saw no strategic fit as they were pivoting away from oncology, (ii) had concerns around the high investment required to conduct the pivotal trials in head and neck squamous cell carcinoma and reach key readouts, (iii) viewed the space as too competitive and/or (iv) generally had different strategic priorities at the time. Despite the broad outreach, counterparties showed minimal interest in an acquisition or merger with the Company or in-licensing any of the Company’s clinical programs. Even a potential split sale of the Company’s oncology and infectious disease platforms did not gain traction with any of the parties that Moelis contacted. As part of the strategic review process, the Company’s management approached Gilead and

another large Company stockholder on several occasions. Both parties were unwilling to provide further capital to the Company as a standalone business; however, both signaled potential support for any future fundraising effort concurrent with a strategic transaction. In addition, Gilead did not express interest in acquiring the Company or its assets at this time.

Also in September 2024, the Company implemented an additional 20% reduction in workforce, the second reduction after the 30% reduction in workforce announced in January 2024.

In October and November of 2024, representatives of the Company and representatives of Gilead had informal discussions regarding the possibility of a strategic transaction.

On October 17, 2024, the Board held a meeting at which they discussed the results of the outreach conducted by Moelis summarized above. The Board discussed with its outside advisors any other alternatives that might be available to the Company, including potential reverse mergers. In connection with these discussions, the Board also reviewed the Company’s forecasted cash positions and determined that at its current cash burn rate it would not be able to remain solvent for an extended period of time. As a result, the Board determined to reduce the Company’s spending on a prompt basis and to continue to explore other strategic alternatives. In addition, the Board discussed the possibility of a dissolution and winding up of the Company, and the distribution of any remaining cash to its stockholders after satisfying all of its liabilities, as a potential alternative to a strategic transaction if no strategic transaction materialized that would provide greater value to the Company’s stockholders.

In early November 2024, the Board determined that standalone fundraising alternatives to extend the Company’s cash runway were highly unlikely due to the lack of meaningful near-term value inflection points. Consequently, the Board asked management to review cash conservation initiatives.

On November 11, 2024, the Board held a meeting at which they discussed the results of the discussions with Company A and Poolbeg. The Board noted that it was unlikely that Company A was going to submit a proposal but was still awaiting further feedback from Company A. The Board directed Company management and Moelis to continue discussions, and gather additional information regarding potential transactions, with Company A and Poolbeg.

On November 17, 2024, the Company received an initial non-binding term sheet merger proposal from Poolbeg.

On November 18, 2024, the Company approved a plan to continue to improve its cost structure and operating efficiency, which included a reduction in the Company’s workforce by approximately 80% of the Company’s then-current employee base (the “Restructuring Plan”). This initiative marked the Company’s third headcount reduction effort in 2024, following both the 30% reduction in workforce announced in January 2024 and the additional 20% reduction implemented in September 2024. In connection with the Restructuring Plan, in an effort to rebalance the Company’s cost structure in alignment with the Company’s strategic refocus and development of its oncology portfolio, the Company also announced that it would pause clinical development of its HB-200 program for the treatment of HPV16+ head and neck cancers, including an early termination of the Company’s ongoing Phase 1/2 H200-001 clinical trial for the treatment of HPV16+ cancers and Phase 2/3 H200-004 clinical trial, and that the Company would focus primarily on progressing the phase 1-ready HB-700 program for the treatment of KRAS mutant cancers.

On November 20, 2024, the Board held a meeting to discuss a potential transaction with Poolbeg and decided to invite management of Poolbeg to discuss their vision of a combined company and the financing Poolbeg intended to obtain in connection with a proposed transaction. At the meeting, the Board discussed how a transaction with Poolbeg could enable a pathway to continue development of the HB-700 program and allow Company stockholders to receive value for any net cash at closing. Subsequently, the Board authorized the Company’s management to move forward with negotiating the key terms of the contemplated potential transaction with Poolbeg with the aim of signing a non-binding term sheet as soon as practicable. The Board held several meetings during the following months at which it received updates from the Company’s management and advisors regarding the proposed transaction with Poolbeg.

In November and December of 2024, the Company and Poolbeg conducted due diligence and hosted numerous functional diligence calls.

From November 17, 2024 to December 19, 2024, the Company and Poolbeg negotiated a proposed term sheet. As part of the term sheet negotiations, the Company and Poolbeg pursued a concurrent private placement financing

transaction (“PIPE”) in order to provide sufficient capital for the combined business to realize meaningful expected value inflection points, including (i) Phase 1 interim data for HB-700 in H1 2026, (ii) Phase 2a topline data for POLB 001 in H2 2026 and (iii) primary completion of the Phase 1b trial of HB-500 in H2 2025.

On November 26, Gilead’s Senior Vice President of Corporate Development and Gilead Alliance Management personnel held a call with Ms. Coelho where Gilead representatives proposed a buy out of HB-400 milestones and royalties.

Following several discussions and meetings with Company A in November of 2024 and a preliminary review of terms of a potential non-binding term sheet presented by Company A on December 8, 2024, Company management advised the Board that it did not believe that a combination of the Company and Company A would be feasible due to (i) the combined cash burn of the two companies to key near-term value inflection points, (ii) the need to raise at least $100 million in financing, and (iii) Company management’s expectation that existing stockholders of the Company would not be interested in significantly participating in such financing. The Board then determined not to proceed with a potential transaction with Company A.

On December 17, 2024, the Board, after discussion with management and the Company’s advisors, determined that a merger with Poolbeg was the only strategic alternative to a dissolution of the Company, considering the Company’s significant cash constraints and the low likelihood of any other party emerging for the purchase of the Company, a licensing transaction for HB-200 or HB-700 or any other strategic transaction. Without such a transaction, the Board considered that the Company would be obligated to wind down operations given the lack of cash to fund ongoing clinical development efforts. At that time, the Company was uncertain when it would receive the payment related to receivables from the Austrian research incentive program for the years 2022 and 2023. A dissolution would be associated with a high likelihood of bankruptcy as there might not be sufficient cash to settle all costs to complete the dissolution and liquidation process. Consequently, any payment to the Company’s stockholders as part of the Company’s liquidation would be substantially inferior to the value available to the Company’s stockholders in the proposed transaction with Poolbeg and likely take several years to be determined.

On December 19, 2024, the Company and Poolbeg agreed to the key terms of a non-binding term sheet regarding the proposed transaction.

On January 2, 2025, the Company and Poolbeg publicly announced entering into non-binding discussions for a potential all-share acquisition by the Company of Poolbeg (the “2.4 Announcement”). The 2.4 Announcement was required given that Poolbeg is subject to the regulations of the UK City Code on Takeovers and Mergers (the “UK Takeover Code”) based on its AIM listing (London Stock Exchange) and that the PIPE would be in an amount of up to approximately $30 million.

Following the 2.4 Announcement, the Company and Poolbeg negotiated the terms of definitive agreements providing for the transaction, sought to obtain the financing for the proposed transaction and continued to conduct due diligence. They also coordinated work on the process to obtain approvals for the transaction and the preparation of financing statements required to obtain the approvals and the continued listing of the Company’s shares. The parties also held regular meetings to discuss these items. The Board held several meetings during the following months at which it received updates from the Company’s management and advisors regarding the proposed transaction with Poolbeg. During these meetings, the Board routinely sought to expedite the process to reach final resolution of the terms of the proposed transaction and to obtain greater certainty regarding the terms of the financing for the proposed transaction. During these meetings, the Board also continued to review the Company’s cash position and evaluated whether a dissolution would be more favorable to the Company than the proposed transaction with Poolbeg.

In mid-February 2025, the Company received a payment of $19.8 million related to receivables from the Austrian research incentive program for the years 2022 and 2023. As a result of this payment, the Company’s cash position and the likelihood that it could undertake a dissolution with expected positive recovery to its stockholders (in lieu of a business combination transaction with a third party) improved.

On February 18, 2025, representatives of Poolbeg sent an email to representatives of the Company raising concerns about whether the PIPE financing would be successful, proposing changes to the economic terms and suggesting that there could be a significant delay in closing, which would result in additional cash burn and expenses.

On February 20, 2025, the Board held a meeting at which it determined to terminate discussions regarding a potential transaction with Poolbeg, which the Board had concluded was highly uncertain on the terms previously

negotiated and no longer worth pursuing, and that it did not intend to make an offer for Poolbeg as a result. The Company subsequently disclosed this finding under the requirements of the UK Takeover Code. No additional parties contacted the Company or its advisors regarding a proposed transaction with the Company following either the 2.4 Announcement or the announcement of the termination of discussions with Poolbeg.

On February 24, 2025, representatives of the Company initiated a call with representatives of Gilead to discuss the termination of discussions with Poolbeg and inform Gilead that the Company was considering a potential dissolution. During the call, the representatives of Gilead indicated that Gilead was interested in discussing a potential strategic transaction with the Company.

On February 25, 2025, the Board held a meeting at which Dr. Peters gave an update on his latest discussions with representatives of Gilead the day before. Dr. Peters also compared the anticipated impacts of an asset sale transaction with a dissolution of the Company with both an acquisition of the Company by Gilead and a dissolution of the Company without any transaction with Gilead, including the potential value to stockholders of each. At such Board meeting, the Company’s outside counsel presented to the Board on the likely timing of a dissolution and limitations on the ability of Hookipa Biotech to liquidate if it had any outstanding obligations. The Board then discussed potential alternative transactions involving Hookipa Biotech. Following discussion, the Board determined to seek to have Gilead agree to acquire the whole Company on terms to be agreed rather than engaging in an asset sale transaction, as it was more likely to be faster and simpler for the Company and result in greater and faster recovery to the Company’s stockholders, and at the same time to continue to evaluate whether any other transaction involving the Company (including a transaction for Hookipa Biotech) would be viable.

During the following days, representatives of the Company and Gilead and their respective advisors discussed whether Gilead would be prepared to enter into a transaction to acquire the Company.

On March 2, 2025, a representative of Gilead sent a term sheet to representatives of the Company outlining the principal terms of a potential acquisition of certain assets relating to the Sellers’ HB-400 Program and HB-500 Program for a total purchase price of $9 million, $2 million of which would be payable at closing and $7 million of which would be payable following the completion of transfer and support activities relating to the acquired assets.

On March 2, 2025 and March 3, 2025, representatives of Moelis, the Company and Gilead had separate calls at which they discussed the terms of a potential transaction between the parties. Representatives of Gilead indicated that they were not interested in acquiring the entire Company and would only be interested in an acquisition of selected assets of the Company relating to the HB-400 Program and HB-500 Program.

On March 3, 2025, the Board held a meeting to discuss a potential transaction with Gilead. During the meeting, representatives of Moelis noted the discussions that had taken place with Gilead regarding the proposed transaction, including the Company’s preference for an acquisition of the entire Company and Gilead’s response that it would only be interested in an asset sale transaction. The Board discussed unresolved issues regarding the proposed transaction, including the consideration to be paid, the approvals required to complete the transaction (including stockholder approval and Austrian regulatory approval) and the processes required to complete the full data transfer, and the potential to solicit and discuss other potential transactions involving a sale of the entire Company or Hookipa Biotech while the Gilead transaction was pending. The Board also continued to evaluate alternatives involving a dissolution of the Company, alone or together with a proposed transaction with Gilead, a reverse merger transaction and whether there were other transactions that might be more favorable to the Company’s stockholders than the proposed transaction with Gilead, including a potential sale to a financial liquidation firm. After discussion, the Board directed the Company’s management to continue engaging in discussions with Gilead regarding a potential transaction and to get greater clarity on the proposed terms of such a transaction so it could be compared against alternatives, including a dissolution and liquidation of the Company.

On March 4, 2025, a representative of a family office that invests in life sciences companies (“Company B”) reached out to Dr. Peters to ask if the Company would be open to discussing a potential transaction with respect to Hookipa Biotech.

On March 6, 2025, Gilead Alliance Management personnel held a call with Moelis to discuss the Company’s forthcoming changes to the term sheet. Moelis relayed on behalf of the Company the Company’s continued interest in an acquisition of the Company instead of an asset sale transaction.

On March 9, 2025, representatives of the Company sent a revised term sheet back to representatives of Gilead accepting the asset sale structure, proposing a purchase price of $14 million, $7 million of which would be payable

at closing and the remaining $7 million of which would be payable upon the completion of the transfer of the acquired assets based on objective measures, requiring Gilead to assume the employment of employees of Sellers predominantly engaged in the HB-400 Program and HB-500 Program and permitting the Company to be able to seek to monetize its other assets. Representatives of the Company also indicated that they would like to continue to discuss whether an acquisition of the Company in lieu of this transaction was possible.

Also on March 9, 2025, representatives of Moelis, the Company and Gilead had a call to further discuss the terms of a potential transaction. Representatives of the Company explained their view that a sale of the entire Company would be more favorable to both the Company and Gilead for a variety of reasons, including that an entire Company sale would not require any separation or transfer of assets/intellectual property, contract assignments, transition services or transfer activities, a sale of the entire Company was much simpler and could potentially be completed sooner than an asset sale, the Company’s belief that it could continue to apply for an Austrian research grant after a change of control but would not be able to apply for such grant upon a dissolution and Gilead would acquire the Company’s remaining cash.

Also on March 9, 2025, Company B submitted a non-binding proposal based on publicly available information to acquire Hookipa Biotech for its net cash after deduction of financial liabilities, subject to a number of assumptions and due diligence.

On March 11, 2025, Dr. Peters had a call with a representative of Gilead during which such Gilead representative said that Gilead will under no circumstances acquire the Company, Gilead would slightly increase its offer but not to $14 million, Gilead had no interest in acquiring any assets unrelated to the HB-400 Program or HB-500 Program and that Gilead would be sending a revised draft of the term sheet the next day.

Later on March 11, 2025, the Board held a meeting at which a representative of Moelis updated the Board on his discussions with Gilead, including Gilead’s desire to acquire assets related to the HB-400 Program and certain assets related to the HB-500 Program but not the entire Company. Dr. Peters then updated the Board on his latest discussions with Gilead about the terms of a potential transaction, including the potential purchase price, Austrian labor law matters, regulatory approvals and required stockholder approval. The Board then discussed the impacts of the asset sale proposed by Gilead as compared to a sale of the entire Company. The Board determined that (i) Gilead would be unlikely to agree to an acquisition of the entire Company and (ii) based on the prior outreach by Moelis and the Company to prospective counterparties and their discussions with such parties as well as the nature of the proposal received from Company B, the Company was unlikely to receive any other offers for an acquisition of the entire Company.

On March 12, 2025, a representative of Gilead sent a revised term sheet to representatives of the Company, which included a proposed purchase price of $10 million (up from its initial offer of $9 million), $3 million of which would be payable at closing and $7 million of which would be payable upon the completion of the transfer of the acquired assets, as agreed by the parties in the definitive agreement, and the deletion of any requirement to assume the employment of any employees of Sellers. The proposed transaction would include assets that were directly or indirectly related to the HB-400 Program and HB-500 Program, which would limit the ability of the Company to monetize assets only indirectly related to the HB-400 Program or HB-500 Program.

On March 13, 2025, the Board held another meeting at which Ms. Coelho gave an update on the financial forecast of the Company, including an estimate of monthly operating cash forecast. Dr. Peters then updated the Board on the status of his negotiations with Gilead on a term sheet for a potential transaction, which would be structured as a sale of assets related to the HB-400 Program and certain assets related to the HB-500 Program but not an acquisition of the entire Company. Dr. Peters shared his view that based on his discussions with Gilead, Gilead’s latest proposal would be the best and final proposal Gilead would be prepared to make. After a thorough discussion, the Board noted that the term sheet did not have an exclusivity provision and, as a result, the Company could continue discussions regarding alternative transactions even if the Company executed the term sheet. Following discussion, the Board approved the term sheet and authorized Company management to execute the term sheet and move forward with discussions with Gilead on the basis of the terms included in the term sheet presented to the Board but to also continue pursuing potential alternative transactions.

On March 14, 2025, the Company signed the term sheet with Gilead.

On March 25, 2025, the Board held a meeting at which Ms. Coelho gave an update on the financial forecast of the Company, including an estimate of monthly operating cash forecast, as well as a comparison of the estimated cash

available for distribution to stockholders if the Company were to be dissolved without giving effect to the Gilead transaction. Dr. Peters then provided the Board an update on recent conversations with Gilead regarding the proposed asset sale transaction and next steps and timing, including that Gilead continued to conduct due diligence on the relevant assets and review the transaction. The Board discussed possible timelines for the proposed transaction and a delisting and dissolution process to follow the transaction.

On March 27, 2025, a representative of Gilead sent an initial draft of the Asset Purchase Agreement to Company management. The draft Asset Purchase Agreement generally reflected the terms provided in the term sheet; however, it also provided for indemnification by the Company for liabilities relating to the assets, had uncertain timing for payments of the $7 million payment, which was payable in one payment only upon full completion of the asset transfer, included a “fiduciary out” that would permit the Board to change its recommendation to the Company’s stockholders in favor of the transaction but would not allow the Company to pursue transactions to monetize the Company’s other assets, included a three-year non-competition covenant restricting operations of the Company and included other obligations for the Company to be responsible for ongoing obligations of the Programs to be sold.

On March 31, 2025, the Company executed a confidentiality agreement with a European biotechnology company (“Company C”) to explore a potential transaction. An initial call was held between representatives of the Company and Company C on which representatives of the Company inquired whether Company C would be interested in an acquisition of the entire Company. Representatives of Company C responded that they would only be interested in an acquisition of certain assets related to the HB-700 program. Company C conducted comprehensive due diligence over the course of approximately one week, after which they notified the Company that Company C would not be interested in pursuing a transaction with the Company.

On April 3, 2025, the Company executed a confidentiality agreement with Company B to explore a potential acquisition of Hookipa Biotech.

On April 8, 2025, a representative of the Company sent a revised draft of the Asset Purchase Agreement to a representative of Gilead, which among other changes: (i) included an initial draft of the Transfer Plan with a high level list of the documentation and materials that would be required to be transferred to Gilead after the closing; (ii) provided that the Sellers would not be limited from discussing or entering into any agreement with respect to any alternative transaction, including a sale of the Company or Hookipa Biotech, that would not by its terms require the abandonment or termination of the Asset Purchase Agreement or the Asset Sale, which would permit the Company to seek to monetize its other assets or sell the Company; (iii) deleted the three-year non-competition covenant applicable to each Seller; (iv) added certain limitations on the Sellers’ indemnification obligations; (v) added a cap of $350,000 on the Company’s obligation to reimburse Gilead for its out-of-pocket expenses incurred in connection with the Asset Purchase Agreement and the Asset Sale if the Asset Purchase Agreement were to be terminated in certain circumstances; (vi) deleted closing conditions requiring that there would be no governmental actions, laws or orders that limit or restrict Gilead’s ownership, conduct or operation of its business or the Programs or Assets following the Closing; and (vii) limited the closing condition regarding required governmental approvals to a certain specified list of approvals to be agreed.

On April 11, 2025, the Company signed a confidentiality agreement with an investment firm (“Company D”), regarding a potential transaction. Representatives of Company D indicated that it would potentially be interested in acquiring the Company after the closing of the Asset Sale but indicated that their offer would be based on the Company’s net cash and included financial covenants that the Company considered to be onerous. Company D indicated that it was concerned the Company would not have enough cash runway to satisfy such covenants or sufficient cash on hand at closing and ultimately did not submit an offer with respect to any transaction.

On April 16, 2025, the Board held a meeting at which Dr. Peters provided an update on the status of discussions with Gilead regarding the Asset Sale and ongoing operational due diligence. Dr. Peters then reviewed the status of discussions with Company B and Company D. A full discussion ensued, including whether the Company should contact other parties to explore transactions that might create greater or more certain value for the Company’s stockholders, including financial liquidation firms, and the related timing, management and cost constraints on doing so and whether it was likely to add value. The Board determined to revisit this question once more information became available regarding how the other parties are viewing the assets, and authorized management to engage in initial informal calls with potential financial liquidator parties in the interim. At the meeting, the Company’s counsel provided an overview of the most significant issues in the initial draft of the Asset Purchase Agreement received by Gilead and how such issues were addressed in the initial markup of the Asset Purchase Agreement sent to Gilead,

including the ability of the Company to receive the $7 million deferred purchase price, limitations on post-closing liability for the Company, the impact of the transaction on employees, the ability to solicit and discuss other or alternative transactions and the terms regarding the separation of the Company’s assets for the sale (and what would remain for possible sales to other parties). During the course of the meeting, the Board discussed whether to seek a fairness opinion in connection with the Asset Sale with Gilead and, based on the anticipated costs associated with a fairness opinion, the fact that all members of the Board were independent of Gilead, the nature of the transaction and the expertise of the members of the Board, ultimately determined not to request a fairness opinion. Ms. Coelho then provided an update on the financial forecast of the Company, without taking into account the potential Asset Sale or related transaction costs. Ms. Coelho then advised the Board that the Company was expecting to receive a notice of noncompliance with Nasdaq’s minimum bid price rule in mid-May, at which point the Company’s common stock would be delisted from Nasdaq and trade on the over-the-counter market.

On April 19, 2025, representatives of Gilead discussed with Dr. Peters the Company’s willingness to assign and transfer to Gilead the necessary assets for the Programs, including assignment of relevant licenses.

On April 22, 2025, following its initial due diligence investigation of Hookipa Biotech, a representative of Company B sent a non-binding preliminary offer letter to the Company offering to pay a purchase price of net cash plus $100,000 for Hookipa Biotech. The offer letter included a calculation of negative net cash and required the Company to bring projected net cash to zero by the closing of the transaction. Over the next several weeks until the Asset Purchase Agreement was executed on May 21, 2025, Company management continued to have regular discussions with Company B about a potential transaction, and based on such discussions concluded that Company B was unlikely to improve their offer and that the Asset Sale remained the Company’s best opportunity to maximize value for its stockholders.

Also on April 22, 2025, a representative of Gilead sent a revised draft of the Asset Purchase Agreement to Company management, which included, among other changes: (i) consistent with Gilead’s prior draft, the inclusion of the obligation of the Sellers to indemnify Gilead for any damages arising in connection with the transfer of any employees of the Sellers to Gilead by operation of law, certain additional taxes, liabilities resulting from claims by third parties with respect to any of the employees or former employees of the Sellers or third parties alleging to be employees or former employees of the Sellers and the dissolution, winding up or insolvency of the Sellers; (ii) Gilead’s right to setoff any indemnification claims against the $7 million transfer completion payment, consistent with Gilead’s prior draft; (iii) the parties’ fundamental representations surviving until the earlier of six years after the closing and the dissolution of each Seller (instead of one year after the closing provided in the Company’s prior draft), the survival of each party’s covenants, obligations and agreements that contemplates performance after the closing until 90 days after the full satisfaction of such covenant, obligation or agreement (in each case, instead of three years after the closing provided in the Company’s prior draft), but in each case representing compromises from positions in Gilead’s prior draft; (iv) largely consistent with Gilead’s prior draft, the restriction on the Sellers discussing or soliciting any offer for the sale of the Company or Hookipa Biotech unless, subject to certain other requirements, the Board determines that an Acquisition Proposal constitutes a Superior Proposal or is reasonably likely to lead to a Superior Proposal and the Board determines in good faith (after consultation with its legal counsel) that the failure to discuss such Acquisition Proposal and provide certain information to the party making such Acquisition Proposal would be reasonably likely to be inconsistent with its fiduciary duties pursuant to Delaware law, which would limit the ability of the Company to monetize the Company’s other assets or sell the Company; (v) the reinsertion of the closing conditions that no action shall have been taken by any governmental entity, and no law or order shall have been enacted in connection with the Asset Sale, that limits or restricts Gilead’s ownership, conduct or operation of its business or the Programs or Assets following the Closing and that all required governmental approvals shall have been obtained (rather than limited the required approvals to a specified list); (vi) the requirement of the Company to reimburse Gilead’s out-of-pocket expenses incurred in connection with the Asset Purchase Agreement and Asset Sale if the Asset Purchase Agreement is terminated in certain circumstances up to a maximum of $500,000 (instead of $350,000 provided in the Company’s prior draft, but representing a compromise from Gilead’s initial uncapped position); (vii) reinsertion of a three-year non-competition covenant applicable to each Seller; and (viii) the deletion of the requirement for the parties to enter into a separate transition services agreement.

On April 25, 2025, the Board held a meeting to consider the Asset Sale and the Dissolution. At the meeting, Dr. Peters and the Company’s counsel updated the Board on the negotiations of the principal terms of the Asset Purchase Agreement and summarized the extensive outreach and activities performed by the Company over the last several months to explore a strategic transaction or financing transaction, including the potential transaction with

Poolbeg. At the meeting, the Company’s counsel reviewed with the members of the Board their fiduciary duties under Delaware law, as well as the material terms and provisions of the Asset Purchase Agreement. During these meetings, the Company’s counsel also outlined steps to be taken by the Company in connection with a vote of its stockholders to approve a sale of all or substantially all of the Company’s assets under Delaware law, which the Asset Sale may be deemed, and the subsequent Dissolution. The Board then discussed that in the event of a dissolution of the Company or termination of the Collaboration Agreement, Gilead would have the ability, under the Collaboration Agreement, to keep the rights to the HBV and HIV programs with reduced payments owed to Hookipa Biotech, which resulted in very limited negotiation leverage for the Company, and extended negotiations with Gilead would result in the Company incurring additional expenses and increase the risk of Gilead terminating discussions regarding a potential transaction. The Board and Company management continued to discuss the terms of Gilead’s latest draft of the Asset Purchase Agreement, including ongoing discussions with upstream licensors regarding assignment of licenses or entry into new license agreements, given that Gilead was requiring as a condition to the closing of the Asset Sale that such agreements with applicable licensors be in place prior to closing and may not agree to close the transaction without such agreements, and the Board noted that it was important to understand the items that would have to be completed to trigger payment of the $7 million transfer completion payments. In addition, at the meeting, Dr. Peters presented an update on the proposal from Company B to acquire Hookipa Biotech, which was likely to be mutually exclusive with the Asset Sale transaction with Gilead because (i) Gilead would acquire many of the assets of Hookipa Biotech in the Asset Sale and (ii) in Gilead’s latest draft of the Asset Purchase Agreement, Gilead restricted the Company’s ability to discuss or enter into alternative transactions, including a sale of Hookipa Biotech. Following extensive discussions, the Board directed Company management to continue to engage in discussions with Company B while the Company concurrently negotiated the Asset Sale with Gilead.

On April 27, 2025, a Gilead representative sent a revised draft of the Transfer Plan to the Company, which among other things, contemplated that the $7 million transfer completion payments would be payable in three installments of $3 million, $2 million and $2 million upon completion of the three phases of the Transfer Plan.

In consultation with the Company’s counsel, on April 30, 2025, the Company sent a revised draft of the Asset Purchase Agreement to Gilead reflecting, among other changes: (i) that the $7 million transfer completion payments would be payable in installments as set forth in the Transfer Plan; (ii) the deletion of the non-competition covenant; (iii) the addition of the Sellers’ right to continue discussions with third parties regarding alternative transactions (including a sale of the Company or Hookipa Biotech) that would not adversely impact the Programs, sale or license of any of the Assets or would require the abandonment or termination of the Asset Purchase Agreement or the Asset Sale or hinder or delay the consummation of the Asset Sale; (iv) that Gilead would bear any transaction taxes; (v) that survival periods of the Sellers’ fundamental representations be the earlier of three years after closing and the dissolution of each Seller; (vi) a decreased cap on the Company’s obligation to reimburse Gilead’s out-of-pocket expenses if the Asset Purchase Agreement is terminated in certain circumstances of $400,000; and (vii) that a liquidation or dissolution of the Company or Hookipa Biotech would not be limited in any way.

On May 7, 2025, the Company’s counsel and Gilead’s counsel had a call to discuss certain open issues in the Asset Purchase Agreement and the potential timing of the dissolution of the Company and Hookipa Biotech following the closing of the Asset Sale.

On May 9, 2025, the Board held a meeting to discuss the remaining open issues in the Asset Purchase Agreement, including the timing and conditions of the payment of the $7 million transfer completion payments, the cap on the Sellers’ liability with respect to breaches of fundamental representations, the survival period of the Sellers’ fundamental representations, the Sellers’ ability to enter into any agreement to sell any assets Gilead was not acquiring or to sell the entire Company or Hookipa Biotech and restrictions on the timing of dissolution of the Company and Hookipa Biotech, and the latest status of the other transaction documents. Following such discussion, Company management gave an update on the status of discussions with Company B regarding a potential transaction.

Later that day, a representative of Gilead sent a revised draft of the Asset Purchase Agreement to the Company and its counsel, which, among other matters, (i) reflected that the $7 million transfer completion payments would be payable in three installments upon the completion of each of three phases of the Transfer Plan; (ii) accepted the deletion of the non-competition covenant; (iii) accepted the $400,000 cap on Gilead’s expense reimbursement; (iv) consistent with Gilead’s prior positions, prohibited the Sellers from discussing or soliciting alternative transactions other than discussions in connection with a Superior Proposal, subject to certain requirements and limitations, which would limit the ability of the Company to monetize the Company’s other assets or sell the Company; (v) limited each Seller’s right to file for dissolution until each phase of the Transfer Plan was completed;

(vi) required the Sellers’ to bear all transaction taxes, consistent with Gilead’s prior positions; and (vii) provided that Sellers’ fundamental representations with respect to the Company would survive for three years after closing and with respect to Hookipa Biotech would survive until the registration of dissolution of Hookipa Biotech.

On May 10, 2025, a representative of Gilead sent a revised draft of the Transfer Plan to the Company.

On May 13, 2025, Dr. Peters sent a revised draft of the Asset Purchase Agreement to Gilead, which reflected limited changes to Gilead’s prior draft, including: (i) further defining when each of the three transfer completion installment payments would be payable; (ii) permitting the Sellers to, upon the earlier of (x) July 31, 2025 and (y) the completion of certain categories of the Transfer Plan, solicit and discuss any alternative transaction (including a sale of the entire Company or Hookipa Biotech) that would not adversely impact the Programs or the Assets, involve a sale or license of any Asset and not require the abandonment or termination of the Asset Purchase Agreement or Asset Sale or hinder or delay the consummation of the Asset Sale; (iii) requiring Gilead to seek reimbursement for any transaction taxes payable for which it may seek reimbursement and promptly pay to the Sellers any such reimbursement it receives; (iv) shortening the survival period of the Sellers’ fundamental representations to (x) in the case of the Company, one year after closing and (y) in the case of Hookipa Biotech, two business days prior to the filing of dissolution of Hookipa Biotech; (v) limiting Gilead’s right to bring any indemnification claims against Hookipa Biotech following the date that is two business days prior to the filing of dissolution of Hookipa Biotech since Hookipa Biotech would not be permitted to dissolve and liquidate while it was subject to any indemnification obligations; and (vi) providing that the rights of Gilead and its related parties and representatives to bring any indemnification claims (including for breaches of covenants and obligations and other indemnifiable matters), other than in the case of fraud, under the Asset Purchase Agreement, would terminate one year after the closing.

On May 14, 2025, the Company’s counsel sent a revised draft of the Transfer Plan to Gilead’s counsel.

On May 16, 2025, representatives of the Company’s management, Gilead’s management and their respective counsels participated in a conference call to discuss the remaining open issues in the Asset Purchase Agreement and schedules thereto, including the Transfer Plan. On such call, Gilead strongly indicated that: (i) it would not permit the Sellers to discuss any transaction regarding a sale of the Company or Hookipa Biotech with any third party prior to closing of the Asset Sale, subject to the exceptions regarding a Superior Proposal, but that it would permit the Sellers to discuss transactions involving the sale of assets (other than the Assets) as long as such transaction did not adversely impact the Programs or the Assets, require the abandonment or termination of the Asset Purchase Agreement or Asset Sale, hinder or delay the consummation of the Asset Sale, or otherwise negatively impact the rights and obligations of the parties under the Asset Purchase Agreement; (ii) termination of the Sellers’ indemnification obligations after one year would not be acceptable but that it would agree to reduce the cap on the Sellers’ liability with respect to breaches of the Sellers’ fundamental representations after the first and second anniversary of closing to the lesser of (x) the purchase price paid or actually due and $7 million and (y) the purchase price paid or actually due and $3 million, respectively; and (iii) the termination of Hookipa Biotech’s indemnification obligations would occur two business days prior to Hookipa Biotech’s filing for dissolution so long as the Company guaranteed and remained liable for any Hookipa Biotech’s indemnification obligations for the survival periods applicable to the Company and Hookipa Biotech provided notice in advance of such filing. On May 17, 2025, Gilead’s counsel sent a revised draft of the Asset Purchase Agreement to the Company’s counsel reflecting (a) such changes discussed on the call, (b) that neither Seller would be permitted to make a filing for dissolution prior to the date all phases of the Transfer Plan had been completed and (c) a few other changes.

On May 18, 2025, the Company’s counsel sent a revised draft of the Asset Purchase Agreement to Gilead’s counsel with limited changes and Gilead’s counsel sent a revised draft of the Transfer Plan to the Company’s counsel. The revised draft of the Asset Purchase Agreement provided that Hookipa Biotech would be permitted to file for dissolution following the completion of certain categories of the Transfer Plan since delaying dissolution of Hookipa Biotech would lead to Hookipa Biotech incurring additional costs that could avoided or reduced by dissolving and that the Company would be permitted to file for dissolution upon the earlier of six months after closing and the date all phases of the Transfer Plan are completed.

On May 19, 2025, Gilead’s counsel sent a revised draft of the Asset Purchase Agreement to the Company’s counsel rejecting the changes the Company proposed regarding the timing of the dissolution of the Company and Hookipa Biotech and reverting to Gilead’s prior position that neither Seller could file for dissolution until all phases of the Transfer Plan are completed.

On May 20, 2025, after a call between the Company and its counsel, the Company’s counsel sent a revised draft of the Asset Purchase Agreement accepting the limitations on the timing of the dissolution of the Sellers included in Gilead’s last draft and the Transfer Plan to Gilead’s counsel, and Gilead’s counsel then sent revised drafts of the Transfer Plan to our counsel.

On May 20, 2025, the Board held a meeting, with representatives of management and the Company’s counsel also attending. At such meeting, the Company’s counsel reviewed each of the material terms of the Asset Purchase Agreement and the process of seeking stockholder approval of the Asset Sale and Dissolution. During such meeting, Dr. Peters reviewed the comprehensive strategic process conducted by the Company to date, the Company’s cash position, and his view that the Gilead transaction remained the best available option to maximize stockholder value. After extensive discussion, the Board unanimously (i) determined that the Asset Purchase Agreement, the Asset Sale, the Transfer Plan and the transactions contemplated thereby are fair to and in the best interest of the Company and its stockholders and declared it advisable for the Company to enter into the Asset Purchase Agreement, (ii) approved the Asset Purchase Agreement, the Asset Sale, the Transfer Plan and the transactions contemplated thereby and (iii) directed that the Asset Sale and Asset Purchase Agreement be submitted for approval by the Company’s stockholders at the Special Meeting. Following discussion on the Dissolution, the Board also unanimously approved the Dissolution and the Company taking steps to effect the Dissolution. The Board also approved certain amendments to Dr. Peter’s employment agreement in connection with the Asset Sale and Dissolution.

On May 21, 2025, Gilead’s counsel sent a final version of the Asset Purchase Agreement to the Company’s counsel with a few minor clean-up comments.

On May 21, 2025, the Company and Hookipa Biotech executed the Asset Purchase Agreement with Gilead.

The Board, acting with the advice and assistance of its legal counsel, evaluated the Asset Purchase Agreement and, acting with the advice and assistance of its legal counsel, evaluated the consideration negotiated with Gilead and its representatives. After careful consideration, the Board determined that (i) the Asset Sale is advisable and fair to and in the best interests of the Company and our stockholders and (ii) the form, terms and provisions of the Asset Purchase Agreement and the Asset Sale are advisable and fair to and in the best interests of the Company and our stockholders. At a meeting of the Board held on May 20, 2025, the Board discussed and resolved to adopt and approve the Asset Purchase Agreement and the transactions contemplated thereby, and to recommend to our stockholders that they vote for the approval of the Asset Sale. For additional information regarding the Board’s discussion and approval of the Asset Sale, see “The Asset Sale (Proposal No. 1) — Background of the Asset Sale” beginning on page 30.

In the course of reaching its determinations, the Board consulted with our management and our financial and legal advisors and considered a number of substantive factors, both positive and negative, and potential benefits and detriments of the Asset Sale. The Board believed that, taken as a whole, the following factors supported its decision to approve the Asset Sale:

The Board determined that if we could secure a high enough price for the Company or its assets, in whole or in part, through a sales process, a sale of the Company or its assets could result in a better return for stockholders than continuing a growth strategy.

The Board also considered a variety of risks and other potentially negative factors relating to the Asset Sale, including the following:

In addition, the Board was aware of and considered the interests that certain of our directors and executive officers may have with respect to the Asset Sale that differ from, or are in addition to, their interests as stockholders of the Company, as described in “— Interests of our Directors and Executive Officers in the Asset Sale”.

The foregoing discussion summarizes the material factors considered by the Board in its consideration of the Asset Sale. In light of the variety of factors and the quality and amount of information considered, as well as the complexity of these matters, the Board did not find it practicable to, and did not attempt to, make specific assessments of, quantify, rank or otherwise assign relative weights to the specific factors considered in reaching this determination. The Board conducted an overall analysis of the factors described above, as well as others, including thorough discussion with, and questioning of, our senior management and our legal and financial advisors, and considered the benefits of the Asset Sale to outweigh the risks and the factors overall to be favorable to, and to support, its determination. Individual members of the Board may have given different weight to different factors.

After careful consideration, the Board unanimously recommends that you vote “FOR” the approval of the Asset Sale pursuant to the Asset Purchase Agreement.

Pursuant to the terms of the Asset Purchase Agreement, the Company will receive aggregate cash consideration of up to $10.0 million, of which $3.0 million shall be payable upon closing and up to $7.0 million shall become payable in three stages upon completion of the Transfer Plan, with $3.0 million payable upon completion of the first phase and $2.0 million payable upon completion of each of the second and third phases. Completion of the first phase of the Transfer Plan requires the transfer of certain know-how, records, documents, and other information and materials relating to the HB-400 Program and the HB-500 Program to Gilead. Completion of the second phase of the Transfer Plan requires the assignment to Gilead of certain transferred contracts relating to the HB-400 Program and the HB-500 Program (or an alternative arrangement mutually agreed between us and Gilead) and the transfer of patent file histories relating to the patents assigned to Gilead under the Asset Purchase Agreement. Completion of the third phase of the Transfer Plan requires the performance of certain transfer services such as drafting a comparability protocol, preparing an interim analysis, and providing assistance to Gilead with respect to manufacturing processes and updates to stability documents and change controls. Completion of each of the phases of the Transfer Plan will occur 30 days after we notify Gilead that such phase has been completed, and we may undertake activities under these phases concurrently. However, Gilead may dispute such notification of completion, in which case completion will only take place once we and Gilead agree that all tasks under a given phase have been completed. Consequently, if Gilead disputes the completion of a phase of the Transfer Plan, our receipt of the cash consideration for such phase may be delayed until we and Gilead agree that all tasks under such phase have been completed. If we and Gilead cannot agree that all tasks under a given phase have been completed, we may never receive the cash consideration for that given phase, subject to resolution of that dispute under the terms of the Asset Purchase Agreement in our favor.

Assuming the Dissolution Proposal is approved by stockholders and the Dissolution becomes effective, we plan to make distributions to the stockholders, subject to a contingency reserve for remaining costs and liabilities including those stemming from the Asset Purchase Agreement, of available proceeds, including from the Asset Sale, if any, after the filing of a Certificate of Dissolution with the Delaware Secretary of State. The amount and timing of any distributions to stockholders will be determined by the Board in its discretion. On the bases described in this proxy statement, the Board anticipates that any distribution to stockholders will not occur any earlier than the date that is three years after the filing of the Certificate of Dissolution and may be approximately $1.28 to $1.72 per share of common stock and Class A common stock (based on 9,799,053 shares of common stock and 2,399,517 shares of Class A common stock outstanding on the record date), after taking into account currently known and estimated expenses and liabilities, and assuming the entire $10.0 million purchase price in the Asset Sale is paid to the Sellers and no indemnification claims are made under the Asset Purchase Agreement. However, there can be no assurance as to the timing and amount of distributions, if any, to our stockholders because there are many factors, some of which are outside of our control, that could affect our ability to make such distributions.

In the event that stockholders do not approve the Dissolution Proposal, we will still seek to complete the Asset Sale, if the Asset Sale is approved by the stockholders and the other conditions to closing set forth in the Asset Purchase Agreement are satisfied or waived. If the Asset Sale is completed, we will have no product candidates that generate revenue, no marketing and sales organization, no experience in marketing products, and no Plan of Dissolution approved, the Company anticipates that it would use its cash to pay ongoing operating expenses, and the Board would convene to determine whether to pay any dividends to the stockholders. The Board would have to evaluate the alternatives available to the Company, including, among other things, remaining a publicly traded company or undertaking a going private transaction. In the event that we make a distribution outside of the Plan of Dissolution, our stockholders could incur an increased tax liability if the property (including cash from the Asset Sale) distributed to stockholders is characterized as a dividend for U.S. federal income tax purposes (see the section entitled “Material United States Federal Income Tax Consequences of the Dissolution to Hookipa Stockholders”).

We are organized under the corporate laws of the State of Delaware. The Asset Sale may constitute the sale of “substantially all” of our property and assets under Section 271 of the DGCL. Section 271 of the DGCL requires that a Delaware corporation obtain the approval of the holders of a majority of the corporation’s outstanding stock entitled to vote thereon for the sale of “all or substantially all of its property and assets.” In light of this requirement, after taking into account the specific facts and circumstances of the Asset Sale, we have determined to seek stockholder approval of the Asset Sale. Additionally, obtaining such stockholder approval is a closing condition under the Asset Purchase Agreement.

Certain of our directors and executive officers may have interests in the Asset Sale that are different from, or in addition to, those of our stockholders generally. These interests may create potential conflicts of interest. The Board was aware that these interests existed when it approved the Asset Purchase Agreement and the Asset Sale. All such interests are described below to the extent material, and except as described below, such persons have, to our knowledge, no material interest in the Asset Sale apart from those of stockholders generally.

On May 20, 2025, Hookipa Biotech and Dr. Malte Peters, our Chief Executive Officer, entered into an amendment (the “Employment Agreement Amendment”) to Dr. Peters’ existing Employment Agreement, dated July 22, 2024 (the “Employment Agreement”). Pursuant to the Employment Agreement Amendment, which will become effective upon the closing of the Asset Sale, Dr. Peters will assume additional responsibility for liquidating Hookipa Biotech as efficiently as possible if and when the Company, as the sole shareholder of Hookipa Biotech, approves the dissolution of Hookipa Biotech (such date, the “Subsidiary Dissolution Date”). Additionally, the Employment Agreement Amendment provides that, in light of consummation of the Asset Sale constituting a Change in Control within the meaning of the Employment Agreement, Dr. Peters shall become eligible for the cash severance benefits described in Sections 5.1(a)(i) of the Employment Agreement and accelerated vesting of his outstanding stock option and restricted stock unit equity incentive awards as described in Section 5.1(a)(iii) of the Employment Agreement, 50% of which is payable (or will vest and be settled, as the case may be) within 14 days following the closing of the Asset Sale and the remainder of which will be payable (or vest and be settled) within 30 days following the date when, with certain exceptions, Hookipa Biotech’s business has been fully wound down. Pursuant to the Employment Agreement Amendment, Dr. Peters will release any claims he may have as of the closing of the Asset Sale.

Dr. Peters will continue to receive his current base salary as of the effective date, but all incentive compensation agreements or awards for which Dr. Peters is otherwise eligible will be replaced with an incentive compensation bonus (the “Special Dissolution Success Bonus”) that is payable upon completion of the dissolution of Hookipa Biotech in an amount ranging from 150% to 75% of Dr. Peters’ current target performance bonus (55% of base salary): the Special Dissolution Success Bonus will be paid at the 150% level (€482,591) if the completion occurs within eight months following the Subsidiary Dissolution Date, and the bonus will decrease by 16²∕3% per month if the completion occurs during the following three months (i.e. the bonus would be payable at 100% (€321,727) if the completion occurs during the month ending on the eleven-month anniversary of the Subsidiary Dissolution Date) and decrease by an additional 8¹∕3% per month thereafter, with no Special Dissolution Success Bonus payable if the dissolution is not completed by the 14-month anniversary of the Subsidiary Dissolution Date.

The term of the Employment Agreement, as amended by the Employment Agreement Amendment, will end on the 17-month anniversary of the Subsidiary Dissolution Date, unless terminated earlier by either party. Pursuant to the Employment Agreement Amendment, each of Hookipa Biotech and Dr. Peters may terminate the Employment Agreement with two months’ notice, and if prior to the 14-month anniversary of the Subsidiary Dissolution Date Hookipa Biotech terminates Dr. Peters and there is no good cause for doing so that corresponds to a reason for dismissal within the meaning of Section 27 of the Austrian Salaried Employees Act, or Dr. Peters resigns for good cause within the meaning of Section 26 of the Austrian Salaried Employees Act, Dr. Peters will be entitled to the Special Dissolution Success Bonus that would be payable upon completion of the dissolution as of the termination date.

A “sale event” as defined under our Equity Plans may occur in the event that the Asset Sale is completed. Under the Equity Plans, a “sale event” will be deemed to have occurred in circumstances including, but not limited to, the sale of all or substantially all of the assets of the Company on a consolidated basis to an unrelated person or entity. If the Asset Sale is deemed to constitute a sale event under the Equity Plans, all options and stock appreciation rights with time-based vesting conditions or restrictions that are not vested and/or exercisable immediately prior to the effective time of the sale event shall become fully vested and exercisable as of the effective time of the sale event, all other awards with time-based vesting, conditions or restrictions shall become fully vested and nonforfeitable as of the effective time of the sale event, and all awards with conditions and restrictions relating to the attainment of performance goals may become vested and nonforfeitable in connection with a sale event in the discretion of the Board or the Compensation Committee, or to the extent specified in the relevant award. Neither the Board nor the Compensation Committee has determined whether to exercise such authority in connection with the completion of the Asset Sale. As of June 11, 2025, there were 178,570 restricted stock units and 32,864 options issued and unvested held by certain of our officers and directors that will be accelerated, pursuant to the terms of the Equity Plans.

Appraisal rights are a statutory remedy available in many states to stockholders who object to certain extraordinary actions taken by a corporation, such as mergers or certain other change of control transactions. This remedy typically allows dissenting stockholders to require the corporation to buy their stock at a price equal to its fair value immediately before the extraordinary corporate action is taken. Under Delaware law, our stockholders are not entitled to appraisal rights in connection with the Asset Sale.

Mergers and acquisitions that may have an impact in the United States are subject to review by the Department of Justice and the Federal Trade Commission to determine whether they comply with applicable antitrust laws. We believe that the Asset Sale is not subject to the Hart-Scott-Rodino Antitrust Improvements Act of 1976 or the reporting and waiting requirements of any other U.S. antitrust law. However, completion of the Asset Sale is subject to certain FDI clearances as detailed below. Although we believe that Gilead will be able to obtain clearance in a timely manner, we cannot be certain when or if Gilead will do so.

The Asset Sale is subject to the approval (or decision that no approval is required) by the Austrian Federal Ministry of Economy, Energy and Tourism (Bundesminister für Wirtschaft, Energie und Tourismus) pursuant to the Austrian Investment Control Act (Investitionskontrollgesetz).

If the Asset Sale is consummated, it is expected to be accounted for as a “sale” by the Company, as that term is used under generally accepted accounting principles, for accounting and financial reporting purposes.

The following is a summary of certain of the terms of the Asset Purchase Agreement. This summary does not purport to describe all the terms of the Asset Purchase Agreement and is qualified in its entirety by reference to the full text of the Asset Purchase Agreement, which is attached as Annex A. We urge you to read the Asset Purchase Agreement carefully and in its entirety because it, and not the summary set forth in this proxy statement, is the legal document that governs the Asset Sale.

The representations, warranties and covenants contained in the Asset Purchase Agreement were made only for purposes of the Asset Purchase Agreement as of specific dates and may be subject to more recent developments. Such representations, warranties and covenants were made solely for the benefit of the parties to the Asset Purchase Agreement, may be subject to limitations agreed upon by the contracting parties, including being qualified by confidential disclosures made for the purposes of allocating risk between the parties instead of establishing these matters as facts, and may apply standards of materiality in a way that is different from what may be viewed as material by you or by other investors. For the foregoing reasons, you should not rely on the representations, warranties and covenants or any descriptions thereof as characterizations of the actual state of facts or condition of the parties or any of their respective subsidiaries or affiliates.

Under the terms of the Asset Purchase Agreement, Gilead will purchase all assets primarily related to, or necessary for the conduct of, our HB-400 Program, and certain assets related to our HB-500 Program, including all know-how and patent rights that are necessary or reasonably useful for researching, developing, manufacturing or commercializing HBV an HIV products.

Aggregate consideration for the sale of the Assets will consist of up to $10.0 million, of which $3.0 million shall be payable upon closing and up to $7.0 million shall become payable in three stages upon completion of the Transfer Plan, with $3.0 million payable upon completion of the first phase and $2.0 million payable upon completion of each of the second and third phases of the Transfer Plan.

The closing will take place at 11:59:59 p.m. Eastern Time on a date no later than the fifth business day after the satisfaction or waiver of the closing conditions set forth in the Asset Purchase Agreement, or at such other time, date and location as the parties agree in writing (the “Closing Date”).

The Sellers made representations and warranties relating to, among other things:

Additionally, Gilead made representations and warranties relating to the following matters:

The representations and warranties made by each of the Sellers and Gilead in the Asset Purchase Agreement, except for certain fundamental representations of each of the Sellers and Gilead, will terminate and expire as of the closing of the Asset Sale. The fundamental representations of the Sellers (which include representations and warranties relating to corporate organization, existence, good standing and power and authority to carry on our business; corporate power and authority to enter into the Asset Purchase Agreement and related agreements and to consummate the Asset Sale; enforceability of the Asset Purchase Agreement and related agreements; financial ability to consummate the Asset Sale and solvency; title to assets; the absence of conflicts, violations or breaches under organizational documents or any applicable law; intellectual property and related matters; compliance, licenses and permits; brokers’ and finders’ fees; and fair market value of the consideration for the Assets) and Gilead (which include corporate organization, existence and good standing; corporate power and authority to enter into the Asset Purchase Agreement and related agreements and to consummate the Asset Sale; enforceability of the Asset Purchase Agreement and related agreements; the absence of conflict, violation or breach under organizational documents and any applicable law; and brokers’ and finders’ fees), the tax representations and warranties of the Sellers, and the representations and warranties in any certificate with respect to the foregoing, shall survive the closing until (i) with respect to the Company and Gilead, the third anniversary of the closing or (ii) with respect to Hookipa Biotech, two (2) business days prior to the filing of the application for the registration of deletion (Löschung) pursuant to section 93 para 1 of the Austrian Limited Liability Company Act with the Austrian companies’ register (subject to Hookipa Biotech providing requisite notice to Gilead at least ten (10) business days prior to such filing).

Notwithstanding the foregoing, claims under the Asset Purchase Agreement based on fraud will survive the closing of the Asset Sale until the date that is sixty (60) days after the expiration of the longest statute of limitations with respect thereto.

Until the closing of the Asset Sale, each of the Sellers will use commercially reasonable efforts to, unless otherwise expressly disclosed, permitted or contemplated by the Asset Purchase Agreement, or Gilead otherwise consents in writing:

Additionally, unless expressly disclosed, permitted or contemplated by the Asset Purchase Agreement, or Gilead otherwise consents in writing, neither Seller will:

Notwithstanding the foregoing, prior to the closing of the Asset Sale, the Company will be permitted to dispose of the Excluded Assets (as defined in the Asset Purchase Agreement). Prior to the Closing Date, the Sellers shall exercise, consistent with the terms and conditions of the Asset Purchase Agreement, complete control and supervision of their operations and the Programs in the ordinary course of business consistent with past practice.

Under the Asset Purchase Agreement, until the earlier to occur of the termination of the Asset Purchase Agreement and the closing of the Asset Sale, we and our employees, officers and directors are required not to, and we are required to direct and use reasonable best efforts to cause our other representatives not to, directly or indirectly:

Notwithstanding the above restrictions, until the approval of the Asset Sale by the Company’s stockholders, if the Board has determined in good faith (after consultation with its financial advisor, if any, and legal counsel) that an Acquisition Proposal that did not result in the breach of the above restrictions either constitutes a Superior Proposal or is reasonably likely to lead to a Superior Proposal, the Board has determined in good faith (after consultation with its legal counsel) that the failure to take the following actions would be reasonably likely to be inconsistent with its fiduciary duties pursuant to applicable law and the Company has provided 24 hours prior notice to Gilead of its intention to furnish information to, negotiate with or otherwise engage in discussions with any person involving such Acquisition Proposal, the Company may, directly or indirectly: subject to the entry into, and in accordance with, an acceptable confidentiality agreement, furnish to the person making such a bona fide written Acquisition Proposal (and its representatives and financing sources) non-public information relating to the Sellers or the Programs and afford to such person (and such person’s representatives and financing sources) access to the business, properties, assets, books, records or other non-public information, or to personnel, of the Sellers; provided, however, that the Company shall concurrently provide to Gilead, or provide Gilead access to, any such non-public information concerning the Sellers or the Programs that is provided to any such person or its representatives that was not previously provided to Gilead or its representatives; and participate or engage in discussions or negotiations with such person (and their representatives and financing sources) with respect to such bona fide written Acquisition Proposal.

In addition, if the Company receives an Acquisition Proposal that did not arise from a material breach of its non-solicitation obligations that the Board concludes in good faith (following the receipt of advice from its financial advisor, if any, and legal counsel), is a Superior Proposal, and the Board determines in good faith (following the receipt of advice from its financial advisor, if any, and legal counsel), that changing its recommendation in favor of the Asset Sale would be inconsistent with its fiduciary duties under Delaware law, then the Board may, at any time prior to stockholder approval of the Asset Sale, change its recommendation to stockholders or terminate the Asset Purchase Agreement to enter into an alternative acquisition agreement with respect to such Acquisition Proposal. Notwithstanding the foregoing, the Board may not change its recommendation unless the Company shall have provided prior written notice to Gilead, at least three business days in advance, of the Company’s intention to make a recommendation change or terminate the Asset Purchase Agreement, which notice shall specify the material terms and conditions of the Superior Proposal, and shall have contemporaneously provided copies of the most recent versions of all proposed agreements relating to the Superior Proposal, and shall negotiate with Gilead in good faith (to the extent that Gilead requests to so negotiate) to make such adjustments to the Asset Purchase Agreement and after considering any binding written proposals made by Gilead to amend the terms of the Asset Purchase Agreement prior to the expiration of the three business day notice period, the Board determines in good faith (following the receipt of advice from its financial advisor, if any, and legal counsel) that the Acquisition Proposal continues to be a Superior Proposal (after giving effect to any written proposals made by Gilead) and the failure to change its recommendation in favor of the Asset Sale would be inconsistent with its fiduciary duties under Delaware law.

The restrictions on the Sellers’ solicitation of other offers described above do not restrict the Sellers with respect to the solicitation, pursuit or negotiation of any Non-Conflicting Transactions (as defined below); provided that, if at any point any such solicitation, pursuit or negotiation results, or would reasonably be expected to result in, an Acquisition Proposal, any such solicitation, pursuit or negotiation shall thereafter be subject to such non-solicitation restrictions.

Under the Asset Purchase Agreement, “Acquisition Proposal” means any offer or proposal from a third party to engage in an Acquisition Transaction. “Acquisition Transaction” means any transaction or series of related transactions involving (i) any direct or indirect purchase or other acquisition by any person or “group” (as defined pursuant to Section 13(d) of the Exchange Act) of persons, whether from the Company or any other person(s), of securities representing more than 15% of the total outstanding equity securities of either the Company or Hookipa Biotech (by vote or economic interests) after giving effect to the consummation of such purchase or other acquisition,

including pursuant to a tender offer or exchange offer by any person or “group” of persons that, if consummated in accordance with its terms, would result in such person or “group” of persons beneficially owning more than 15% of the total outstanding equity securities of the either Company or Hookipa Biotech (by vote or economic interests) after giving effect to the consummation of such tender or exchange offer; (ii) any purchase, license or other acquisition by any person or “group” (as defined pursuant to Section 13(d) of the Exchange Act) of persons of either Program, any product or any Asset outside of the ordinary course; or (iii) any merger, amalgamation, consolidation, business combination, recapitalization, reorganization, liquidation, dissolution or other transaction involving either Seller pursuant to which any person or “group” (as defined pursuant to Section 13(d) of the Exchange Act) of persons would hold securities representing more than 15% of the total outstanding equity securities of Company or Hookipa Biotech (by vote or economic interests) after giving effect to the consummation of such transaction. For avoidance of doubt, a liquidation or dissolution of the Company or any of its subsidiaries shall not be an Acquisition Transaction.

Under the Asset Purchase Agreement, “Non-Conflicting Transaction” means a transaction to which either Seller is a party that (i) is not an Acquisition Transaction, (ii) would not adversely impact the Programs, the Assets or the assumed liabilities, (iii) does not involve a sale, transfer, license or other disposition of any Asset and (iv) would not require the abandonment or termination of the Asset Purchase Agreement or the transactions contemplated thereby, hinder or delay the consummation of the transactions contemplated by the Asset Purchase Agreement, or otherwise negatively impact the rights of Gilead or the obligations of the Sellers under the Asset Purchase Agreement.

Under the Asset Purchase Agreement, “Superior Proposal” means any bona fide written Acquisition Proposal by a person other than Gilead or its affiliates that was not the result of a breach of the no solicitation provision of the Asset Purchase Agreement and the Company’s Board has determined in good faith (after consultation with its financial advisor and legal counsel) (i) is reasonably likely to be consummated in accordance with its terms, taking into account all legal, regulatory, timing and financing aspects of the proposal (including certainty of closing and the identity of the Person making the proposal), that the Company’s Board deems relevant, and (ii) if consummated, would be more favorable, from a financial point of view, to the Company’s stockholders (in their capacity as such) than the Asset Sale (taking into account any revisions to the Asset Purchase Agreement made or proposed in writing by Gilead prior to the time of such determination).

Until the earlier of the closing of the Asset Sale and the termination of the Asset Purchase Agreement, the Company will cooperate with Gilead’s investigation of the Assets and provide Gilead and its representatives with reasonable access during normal business hours to the data and other information regarding the Programs, the Assets and assumed liabilities as Gilead may reasonably request, in each case for any reasonable purpose related to the consummation of the transactions contemplated by the Asset Purchase Agreement.

The Asset Purchase Agreement contains numerous covenants that apply to the Sellers and Gilead, respectively.

The covenants that are specific to the Sellers generally relate to, among other things: the conduct of the Programs, and related matters, before the closing of the Asset Sale (as described above); providing Gilead with access to, and deliveries of, certain information (as described above); ceasing all activity regarding alternative acquisition proposals, except with respect to unsolicited alternative acquisition proposals (as described above); holding a meeting of the Company’s stockholders and soliciting proxies from the Company’s stockholders to obtain the approval of the Asset Purchase Agreement and the Asset Sale by the Company’s stockholders; cooperation and efforts to close the Asset Sale; and the release of all liens on the assets of the Company.

In addition, the Asset Purchase Agreement:

Following the closing of the Asset Sale, each of the Sellers shall remain in existence as necessary to assist Gilead with the execution of the Transfer Plan and provide Gilead with reasonable access, upon reasonable advance notice, the books and records of such Seller relating to the Assets and the Assumed Liabilities with respect to (i) periods or occurrences prior to the closing, and (ii) officers, employees and independent contractors of such Seller.

Further, at or following the closing, the Sellers shall transfer the Assets as required by applicable laws, the terms and conditions of the Asset Purchase Agreement, and the Transfer Plan. Following the closing, for a period ending on the earlier of (x) six (6) months after the closing and (y) the date all phases of the Transfer Plan are completed, the Sellers shall reasonably cooperate in all respects with Gilead in connection with the transfer of the Assets, including (i) assisting Gilead with the transfer of the Assets and (ii) providing any information requested by Gilead related to the Assets.

Completion of the first phase of the Transfer Plan requires the transfer of certain know-how, records, documents, and other information and materials relating to the HB-400 Program and the HB-500 Program to Gilead. Completion of the second phase of the Transfer Plan requires the assignment to Gilead of certain transferred contracts relating to the HB-400 Program and the HB-500 Program (or an alternative arrangement mutually agreed between us and Gilead) and the transfer of patent file histories relating to the patents assigned to Gilead under the Asset Purchase Agreement. Completion of the third phase of the Transfer Plan requires the performance of certain transfer services such as drafting a comparability protocol, preparing an interim analysis, and providing assistance to Gilead with respect to manufacturing processes and updates to stability documents and change controls. Completion of each of the phases of the Transfer Plan will occur 30 days after we notify Gilead that such phase has been completed, and we may undertake activities under these phases concurrently. However, Gilead may dispute such notification of completion, in which case completion will only take place once we and Gilead agree that all tasks under a given phase have been completed. Consequently, if Gilead disputes the completion of a phase of the Transfer Plan, our receipt of the cash consideration for such phase may be delayed until we and Gilead agree that all tasks under such phase have been completed. If we and Gilead cannot agree that all tasks under a given phase have been completed, we may never receive the cash consideration for that given phase, subject to resolution of that dispute under the terms of the Asset Purchase Agreement in our favor.

Each party’s obligation to consummate the Asset Sale is subject to the satisfaction of the following conditions:

Gilead’s obligations to consummate the Asset Sale are subject to the satisfaction of the following further conditions:

The Sellers’ obligations to consummate the Asset Sale are subject to the satisfaction of the following further conditions:

The Asset Purchase Agreement may be terminated at any time prior to the closing of the Asset Sale as follows:

The Company is required to reimburse Gilead for its reasonable, documented out-of-pocket expenses incurred by Gilead in connection with the Asset Purchase Agreement and the Asset Sale up to $400,000, in the event that the Asset Purchase Agreement is terminated as follows:

The representations, warranties, covenants and other agreements contained in the Asset Purchase Agreement or any certificate delivered in connection with the Asset Purchase Agreement, will survive the completion of the Asset Purchase Agreement as follows:

Subject to the terms and conditions of the Asset Purchase Agreement, Hookipa Biotech, severally but not jointly, and the Company, jointly and severally, have agreed, to indemnify Gilead, Gilead’s affiliates and each of their respective members and representatives, against, and hold them harmless from, any and all losses resulting from or arising in connection with:

Effective as of the closing, the Company has agreed to guarantee the obligations of Hookipa Biotech under the Asset Purchase Agreement and other transaction documents, including the Collaboration Agreement, notwithstanding any limitation on Gilead’s right to bring indemnification claims against Hookipa Biotech within the time periods describe above with respect to such obligations.

Gilead has the right to withhold the amount of any claims for indemnifiable damages, and set-off any such amounts, from the $7.0 million transfer completion payments. Gilead is not entitled to any indemnification for losses related to breaches of certain representations and warranties of the Sellers until Gilead suffers at least $100,000 of damages, and then Gilead is entitled to recover from the first dollar of damages.

Subject to certain exclusions in the case of claims of fraud against the Sellers or the insolvency of the Sellers, in no event shall a Seller’s aggregate liability to Gilead for indemnification claims pursuant to a breach of certain fundamental representations in the Asset Purchase Agreement or in any certificate delivered pursuant to the Asset Purchase Agreement, to the extent related thereto, exceed an amount equal to:

No indemnified party is entitled to be indemnified for any punitive damages, damages for lost profits or diminution in value or consequential, exemplary or special damages under the Asset Purchase Agreement, except as a result of direct damages therefor or arising out of, or involving a claim made by a third party.

The Asset Purchase Agreement may not be amended, modified, altered or supplemented, in whole or in part, other than by means of a written instrument, duly executed and delivered by Gilead and the Sellers.

Transaction taxes related to the Asset Sale generally shall be borne by the Sellers, provided that Gilead shall, upon the reasonable request of the Sellers, reasonably cooperate with the Sellers to minimize the amount of transaction taxes that shall be payable as a result of the Asset Sale.

Under the Collaboration Agreement, the Hookipa Biotech is responsible for conducting the HB-500 Phase 1b clinical trial, which trial is currently ongoing. In connection with entering into the Asset Purchase Agreement, Hookipa Biotech and Gilead entered into a letter agreement, pursuant to which Gilead consented to the Company’s request to wind-down the HB-500 trial.

At the Special Meeting, stockholders will be asked to consider and vote upon a proposal to approve the Dissolution. The Board has approved the Dissolution and the Plan of Dissolution, subject to stockholder approval. Under the DGCL, the affirmative vote of the holders of a majority of all the issued and outstanding shares of common stock is required to approve the Dissolution.

Attached as Annex B to this proxy statement is the Plan of Dissolution. The features of the Plan of Dissolution, and other information regarding the winding up of the Company, are summarized below. The following summary of the Plan of Dissolution is not a complete summary and is subject in all respects to the provisions of, and is qualified by reference to, the Plan of Dissolution. Stockholders are urged to read the Plan of Dissolution in its entirety.

The amount and timing of any distributions to stockholders will be determined by the Board in its discretion. The Board anticipates that any distribution to stockholders will not occur any earlier than the date that is three years after the filing of the Certificate of Dissolution and may be approximately $1.28 to $1.72 per share of common stock and Class A common stock (based on 9,799,053 shares of common stock and 2,399,517 shares of Class A common stock outstanding on the record date), after taking into account currently known and estimated expenses and liabilities, and assuming the entire $10.0 million purchase price in the Asset Sale is paid to the Sellers and no indemnification claims are made under the Asset Purchase Agreement. However, there can be no assurance as to the timing and amount of distributions, if any, to our stockholders because there are many factors, some of which are outside of our control, that could affect our ability to make such distributions.

The Board unanimously approved the Dissolution and the Plan of Distribution and declared the advisability thereof. The Board recommends that stockholders vote “FOR” the Dissolution Proposal. Approval of the Dissolution Proposal will constitute the required stockholder approval to dissolve and liquidate the Company as described in the Plan of Dissolution.

In considering the Dissolution, the Board considered the terms of the Plan of Dissolution and the dissolution process under the DGCL, as well as other available strategic options. As part of the Board’s evaluation process, the Board considered the risks and timing of each strategic option available to the Company, and consulted with its financial advisor, management and the Company’s legal counsel. In approving the Dissolution and the Plan of Dissolution, the Board considered a number of factors, including but not limited to, the factors described elsewhere in this proxy statement as well as the following factors:

The Board also considered certain material risks or potentially adverse factors in making its determination and recommendation, including, but not limited to, the following:

The members of the Board did not quantify or otherwise assign relative significance to any of the factors considered when making their determination, but instead considered whether the factors as a whole justified recommending the Dissolution Proposal to the stockholders. The foregoing summarizes the material factors and risks considered by the Board, but it is in no way meant to be exhaustive of the discussion and information considered by the Board. In view of its many considerations, the Board did not quantify or otherwise assign relative significance to any factor considered. In addition, each member of the Board may have given different significance to each factor.

The approval of the Dissolution Proposal will authorize the Board to wind up the affairs of the Company, to cease operating the business for which the Company was organized and to finally terminate the existence of the Company.

The Board unanimously approved the Dissolution and the Plan of Dissolution. The Dissolution and the Plan of Dissolution must be approved by the holders of a majority of the voting power of the issued and outstanding shares of capital stock entitled to vote thereon.

Following the consummation of the Asset Sale and Transfer Plan, the Company, acting by an officer, employee, or agent, as applicable, will, among other things:

In addition, subject to approval by the Board, under the Plan of Dissolution, the officers, employees and agents of the Company will, as promptly as feasible, proceed to:

Under the Plan of Dissolution, liquidating distributions, if any, shall be made from time to time after the filing of the Certificate of Dissolution to the stockholders of record, at the close of business on the Final Record Date, to stockholders in accordance with the provisions of the Company’s certificate of incorporation, as amended from time to time, provided that reasonable provision has been made for the payment, satisfaction and discharge of all known, unascertained, or contingent debts, obligations and liabilities of the Company (including costs and expenses incurred and anticipated to be incurred in connection with the sale and distribution of assets and liquidation of the Company). Pursuant to the Plan of Dissolution, liquidating distributions will be made in cash or in kind, including in stock of, or ownership interests in, subsidiaries of the Company and remaining assets of the Company, if any. Such distributions may occur in a single distribution or in a series of distributions, in such amounts and at such time or times as the Board in its absolute discretion, and in accordance with the DGCL, may determine; provided, however, that the Company must complete the distribution of all its properties and assets to its stockholders as provided in the

Plan of Dissolution as soon as practicable following the filing of its Certificate of Dissolution with the Delaware Secretary of State and in any event on or before the tenth anniversary of the Final Record Date (the “Final Distribution Date”).

Under the Plan of Dissolution, the Company may establish and retain or set aside a reasonable amount of cash and/or property to satisfy claims against the Company and its subsidiaries and other obligations of the Company and its subsidiaries, including (a) tax obligations; (b) all expenses of the sale of the Company’s property and assets; (c) the salary, fees, and expenses of members of the Board, management, and employees; (d) expenses for the collection and defense of the Company’s property and assets; (e) the expenses for attorneys and other professional advisors incurred in connection with liquidation and winding up of the Company; and (f) all other expenses related to the dissolution and liquidation of the Company and the winding-up of its affairs. To the extent any unexpended amounts remain in a contingency reserve, such amounts will be distributed to stockholders no later than the Final Distribution Date pursuant to the Plan of Dissolution.

Under the Plan of Dissolution, the Board may, but is not required to, establish a liquidating trust (the “Liquidating Trust”) and distribute assets of the Company to the Liquidating Trust rather than continue to hold the assets in the Company. The Liquidating Trust may be established by agreement with one or more trustees selected by the Board. If the Liquidating Trust is established by agreement with one or more trustees, the trust agreement establishing and governing the Liquidating Trust shall be in form and substance determined by the Board. The trustees will in general be authorized to take charge of the Company’s property, and to sell and convert into cash or other distributable form any and all corporate non-cash or non-distributable assets and collect the debts and property due and belonging to the Company, with power to prosecute and defend, in the name of the Company, or otherwise, all such suits as may be necessary or proper for the foregoing purposes, and to appoint an agent under it and to do all other acts which might be done by the Company that may be necessary, appropriate or advisable for the final settlement of the unfinished business of the Company.

The Plan of Dissolution provides that the Company will continue to indemnify and advance expenses to its officers, directors, employees and agents in accordance with its Certificate of Incorporation and the Bylaws and any contractual arrangements for actions taken in connection with the liquidation and the winding up of the affairs of the Company. The Board is authorized under the Plan of Dissolution to obtain and maintain directors’ and officers’ liability insurance and any other insurance as may be necessary, appropriate, or advisable to cover the Company’s obligations.

If for any reason the Board determines that such action would be in the best interests of the Company, it may abandon the Dissolution or modify or abandon the Plan of Dissolution and all actions contemplated thereunder, including the proposed winding up of the Company, notwithstanding the stockholder approval of the Dissolution, to the extent permitted by the DGCL; provided, however, that the Board may not revoke the Dissolution following the filing of the Certificate of Dissolution without first obtaining stockholder approval in accordance with the DGCL. Upon the abandonment of the Dissolution, the Plan of Dissolution will be void.

Distributions to the stockholders made pursuant to the Plan of Dissolution are intended to be treated as made in complete liquidation of the Company within the meaning of the Internal Revenue Code of 1986, as amended (the “Code”), and the regulations promulgated thereunder. Under the Plan of Dissolution, the adoption of the Plan of Dissolution by the stockholders will constitute full and complete authority for the making by the Board of all such liquidating distributions.

In accordance with the provisions of the Company’s certificate of incorporation, the holders of the Series A Preferred will receive, pari passu with any distribution to the holders of common stock and Class A common stock, an amount equal to $0.001 per share of Series A Preferred, plus an additional amount equal to any dividends declared

but unpaid on such shares. If the assets available for distribution are insufficient to pay the holders of the Series A Preferred such amount in full, then all remaining assets of the Company will be distributed ratably to holders of the Series A Preferred, common stock and Class A common stock in proportion to the respective amounts which would otherwise be payable if all amounts payable on or with respect to such shares were paid in full. The holders of common stock and Class A common stock are entitled to share ratably in any liquidating distributions.

We expect that certain members of our Board and one or more of our remaining officers are expected to oversee the winding up for a period of time following the Final Record Date. As compensation for the foregoing, our remaining directors and officers will continue to receive compensation, as determined by the Board.

The Company has not yet determined an expected completion date of the Dissolution, if any. The Plan of Dissolution, however, provides that all liquidating distributions be made before the tenth anniversary of the effective date of the Plan of Dissolution.

Appraisal rights are a statutory remedy available in many states to stockholders who object to certain extraordinary actions taken by a corporation, such as mergers or certain other change of control transactions. This remedy typically allows dissenting stockholders to require the corporation to buy their stock at a price equal to its fair value immediately before the extraordinary corporate action is taken. Under Delaware law, stockholders do not have dissenters’ rights of appraisal in connection with the Dissolution or Plan of Dissolution.

See “Material United States Federal Income Tax Consequences of the Dissolution to Hookipa Stockholders” below.

If the number of shares of common stock present in person or represented by proxy at the Special Meeting voting in favor of the proposal to approve the Asset Sale or the Dissolution is insufficient to approve the Asset Sale or the Dissolution at the time of the Special Meeting, we intend to adjourn the Special Meeting to a later date or dates in order to enable the Board to solicit additional proxies in respect of the proposal to approve the Asset Sale and the Dissolution.

In this proposal regarding the adjournment of the Special Meeting, we are asking you to approve one or more adjournments of the Special Meeting, if necessary, for the purpose of soliciting additional proxies in favor of the proposal to approve the Asset Sale and the Dissolution. If our stockholders approve the Adjournment Proposal, we could adjourn the Special Meeting and any adjourned session of the Special Meeting and use the additional time to solicit additional proxies, including the solicitation of proxies from stockholders that have previously returned properly executed proxies voting against the Asset Sale or the Dissolution, as applicable. Among other things, approval of the Adjournment Proposal could mean that, even if we had received proxies representing a sufficient number of votes against the Asset Sale or the Dissolution such that the proposal to approve the Asset Sale or the Dissolution, as applicable, would be defeated, we could adjourn the Special Meeting without a vote on the approval of the Asset Sale or the Dissolution, as applicable, and seek to convince the holders of those shares to change their votes to votes in favor of the Asset Sale and the Dissolution. Additionally, we may seek to adjourn the Special Meeting if a quorum is not present at the Special Meeting. The Bylaws also permit the presiding officer of the Special Meeting to adjourn the Special Meeting, whether or not a quorum is present.

Approval of the proposal to approve one or more adjournments of the Special Meeting, if necessary, to allow for the solicitation of additional proxies to approve the Asset Sale and the Dissolution, requires that (i) if a quorum is present at the Special Meeting, the votes properly cast for the proposal exceed the votes properly cast against the proposal and (ii) if a quorum is not present at the Special Meeting, the proposal is approved by the affirmative “FOR” vote of a majority of the shares of common stock present or represented by proxy at the Special Meeting and entitled to vote on the subject matter.

The following discussion is a general summary of the material U.S. federal income tax consequences of the Dissolution to the Company’s stockholders who hold their shares of common stock as a capital assets within the meaning of Section 1221 of the Internal Revenue Code of 1986, as amended (the “Code”) (generally, property held for investment), but does not purport to be a complete analysis of all the potential tax effects. The discussion addresses neither the tax consequences that may be relevant to particular categories of investors subject to special treatment under certain U.S. federal income tax laws (such as financial institutions, dealers in securities, insurance companies, traders in securities who elect to apply a mark-to-market method of accounting, tax-exempt organizations, partnerships, persons who hold shares as part of a hedge, straddle, constructive sale or conversion transaction, persons who acquired their shares through the exercise of employee stock options or otherwise as compensation, former citizens or residents of the United States, persons who hold their stock as qualified small business stock within the meaning of Section 1202 of the Code) nor any tax consequences arising under the laws of any state, local or foreign jurisdiction or any tax consequences under the alternative minimum tax, or estate and gift tax, provisions of the Code.

The discussion below is based upon the Code, Treasury Regulations, administrative rulings and judicial decisions now in effect, all of which are subject to change at any time, either prospectively or retrospectively, by legislative, administrative or judicial action. The following discussion has no binding effect on the IRS or the courts, and assumes that any distributions to stockholders will be in accordance with the Plan of Dissolution. No ruling has been requested from the IRS with respect to the anticipated tax treatment of the Dissolution, and the Company will not seek an opinion of counsel with respect to the anticipated tax treatment summarized herein. There is no assurance that any liquidating trust formed in connection with the Dissolution will be treated as a liquidating trust for U.S. federal income tax purposes or that the distributions made pursuant to the Plan of Dissolution, if any, will be treated as made in complete liquidation of the Company for U.S. federal income tax purposes. If any of the conclusions stated herein proves to be incorrect, the result could be increased taxation at the stockholder level.

If an entity or arrangement treated as a partnership for U.S. federal tax purposes holds common stock, the tax treatment of a person treated as a partner generally will depend on the status of the partner and the activities of the partnership. Partnerships holding common stock and partners in such partnerships should consult their tax advisors regarding the consequences of the Dissolution to them.

THE FOLLOWING DISCUSSION IS FOR GENERAL INFORMATION ONLY, AND DOES NOT CONSTITUTE AND MUST NOT BE CONSTRUED AS TAX ADVICE TO THE STOCKHOLDERS. STOCKHOLDERS ARE URGED TO CONSULT THEIR OWN TAX ADVISORS REGARDING THE TAX CONSEQUENCES TO THEM OF THE DISSOLUTION, INCLUDING ALL ASPECTS OF U.S. FEDERAL, STATE, LOCAL, NON-U.S. AND OTHER TAX CONSEQUENCES.

For purposes of this discussion, the term “U.S. stockholder” means a beneficial owner of Company common stock that is any of the following: (i) a citizen or individual resident of the United States; (ii) a corporation, or other entity taxable as a corporation for U.S. federal income tax purposes, created or organized in the United States or under the laws of the United States, any state thereof or the District of Columbia; or (iii) an estate or trust, the income of which is subject to U.S. federal income taxation regardless of its source.

It is intended that, if the Company consummates the Dissolution and liquidates, distributions to stockholders be treated as made in complete liquidation of the Company. If distributions are made in complete liquidation of the Company, a U.S. stockholder will recognize gain or loss with respect to such distributions equal to the difference between: (i) the sum of the amount of money and the fair market value of property (other than money) distributed to such stockholder; and (ii) such stockholder’s tax basis in the common stock. A stockholder’s tax basis in its shares generally will equal the stockholder’s cost to acquire the common stock, although, depending on various circumstances, that general rule may not apply in a particular case. The gain or loss will be a capital gain or loss, assuming the shares of common stock are held as capital assets. Long-term capital gain recognized by a stockholder that is an individual, estate or trust generally is taxed at a maximum current U.S. federal income tax rate of 20%. Additionally, certain U.S. stockholders who are individuals, trusts or estates are required to pay a Medicare tax of 3.8% (in addition to taxes they would otherwise be subject to) on investment income. In the case of a stockholder

that is a corporation, capital gains are currently taxed at the same rate as ordinary income. The deductibility of capital losses is subject to limitations. The tax basis of any property other than cash received by each stockholder upon Dissolution will be the fair market value of the property at the time of the distribution.

If the Company effects the Dissolution and liquidates, stockholders may receive one (1) or more liquidating distributions, including a deemed distribution of cash. If such distributions are made in complete liquidation of the Company, a stockholder’s gain or loss will be computed on a “per share” basis so that gain or loss is calculated separately for blocks of shares of common stock acquired at different dates and different prices. Each liquidating distribution will be allocated proportionately to each common share owned by a stockholder. Gain will be recognized in connection with a liquidating distribution only to the extent that the aggregate value of all liquidating distributions received by a stockholder with respect to a share exceeds such stockholder’s tax basis for that share. If the amount of the distributions is less than the stockholder’s basis in the common stock, the stockholder will generally recognize a loss in the year the final distribution is received by the stockholder.

If the Company effects the Dissolution and liquidates, the Company will, at the close of the taxable year in which a liquidating distribution is made, provide stockholders and the IRS with a statement of the amount of cash and the Company’s best estimates of the fair market value of any property distributed to the Stockholders during that year as determined by the Company, at such time and in such manner as required by the Treasury Regulations.

If the Dissolution Proposal is not approved (or if it is approved, but one or more distributions are made to stockholders prior to the Plan of Dissolution becoming effective or the distribution otherwise is not characterized as a distribution in complete liquidation of the Company for U.S. federal income tax purposes), the discussion above does not apply to such distributions. Rather, such distributions, if any, will be characterized as dividends to the extent of the Company’s current or accumulated earnings and profits (as calculated for U.S. federal income tax purposes), distributions in excess of the Company’s current or accumulated earnings and profits will then reduce (but not below zero) the stockholders’ basis in their shares, and any excess amounts will be taxable as capital gains. Non-corporate stockholders currently are taxed on the amount of distributions characterized as dividends at a maximum federal income tax rate of 20%, and the Medicare tax of 3.8% applies to dividend income for certain high income individuals, estates and most trusts. Dividends received by corporate stockholders may be eligible for a dividend received deduction.

If the Company transfers assets to the liquidating trust in connection with the Dissolution, the Company intends to structure the liquidating trust so that it will not be treated as an association taxable as a corporation based upon the anticipated activities of the liquidating trust. Accordingly, it is expected that the liquidating trust itself should not be subject to income tax.

If the Company transfers assets to the liquidating trust in connection with the Dissolution, stockholders will be treated for tax purposes as having received a distribution at the time of transfer of their pro rata share of money and the fair market value of property (other than money) transferred to the liquidating trust, reduced by the amount of known liabilities assumed by the liquidating trust or to which the property transferred is subject, and then having contributed such property to the trust. The distribution is intended to be treated as a distribution in complete liquidation of the Company if made pursuant to the Plan of Dissolution. The effect of such a distribution is discussed above in the subsection entitled “Certain U.S. Federal Income Tax Consequences to U.S. Stockholders”.

As owners of the trust, the stockholders will be required to take into account for U.S. federal income tax purposes their pro rata portion of any income, expense, gain or loss recognized by the liquidating trust. The income, expense, gain or loss recognized by the liquidating trust will not affect a stockholder’s basis in the common stock.

As a result of the transfer of property by the Company to the liquidating trust and the ongoing activities of the liquidating trust, stockholders should be aware that they may be subject to tax whether or not they have received any actual distributions from the liquidating trust with which to pay such tax.

The Company has not obtained any IRS ruling as to the tax status of the liquidating trust, if any, and there is no assurance that the IRS will agree with the Company’s conclusion that the liquidating trust should be treated as a liquidating trust for federal income tax purposes. If, contrary to the Company’s expectation, it were determined that the liquidating trust should be classified for federal income tax purposes as an association taxable as a corporation, income and losses of the liquidating trust would be reflected on the liquidating trust’s own tax return rather than being passed through to the stockholders, and the liquidating trust would be required to pay U.S. federal income taxes at

the regular corporate tax rate. Furthermore, much of the above discussion would no longer be accurate. For instance, all or a portion of any distribution made to the stockholders from the liquidating trust could be treated as a dividend. Stockholders may also be subject to liability for state and local taxes with respect to the receipt of liquidating distributions. State and local tax laws may differ in various respects from federal income tax law.

In general, a distribution in respect of the winding up or complete liquidation of a U.S. domestic corporation is treated as a sale or exchange of its shares by its non-corporate stockholders and by its corporate stockholders owning less than eighty percent (80%) of the shares of the liquidating corporation. Gain on this sale or exchange is generally not subject to U.S. federal income tax for non-U.S. stockholders unless:

Although there can be no assurances in this regard, the Company believes it is not a U.S. real property holding corporation.

If any distribution is not pursuant to the Plan of Dissolution or otherwise not treated as a distribution in complete liquidation of the Company, such distribution will constitute a dividend for U.S. federal income tax purposes to the extent of the Company’s current or accumulated earnings and profits as determined for U.S. federal income tax purposes. In general, subject to the discussion below under “— FATCA”, any dividend distributions to a non-U.S. stockholder will be subject to U.S. withholding tax at a rate of 30% of the gross amount (or a reduced rate specified by an applicable income tax treaty), unless the dividends are effectively connected with a trade or business carried on by the non-U.S. stockholder within the United States (and, if required by an applicable income tax treaty, are attributable to a permanent establishment of the non-U.S. stockholder within the U.S.). In order to obtain a reduced rate of withholding, a non-U.S. stockholder will be required to provide a properly executed applicable IRS Form W-8 certifying its entitlement to benefits under a treaty.

Information reporting may apply to distributions made by us to stockholders. In addition, distributions may be subject to backup withholding. Certain U.S. stockholders are exempt from backup withholding, including corporations and certain tax-exempt organizations, and backup withholding generally will not apply to a stockholder who furnishes a correct taxpayer identification number on IRS Form W-9. For non-U.S. stockholders, backup withholding generally will not apply if such holder either certifies its non-U.S. status, such as by furnishing a valid IRS Form W-8BEN, W-8BEN-E, or W-8ECI (or applicable successor forms), or otherwise establishes an exemption. Proceeds from a distribution made pursuant to the Plan of Dissolution and received through a non-U.S. office of a non-U.S. broker generally will not be subject to backup withholding or information reporting. Backup withholding is not an additional tax. Any amounts withheld under the backup withholding rules may be allowed as a refund or a credit against a stockholder’s U.S. federal income tax liability, provided that the required information is timely furnished to the IRS. Stockholders should consult their tax advisors regarding their qualification for an exemption from backup withholding, the procedures for obtaining such an exemption, and any other information reporting requirements in connection with the Dissolution (e.g., certain Holders may be required to include certain information with their U.S. federal income tax returns). In addition, each stockholder should consult with his, her or its own tax advisor the information and backup withholding aspects of the Dissolution, including whether such stockholder needs to include a statement described in Treasury Regulations Section 1.331-1(d)(2) with its U.S. federal income tax return with respect to the Dissolution.

Provisions commonly referred to as “FATCA” impose withholding (separate and apart from, but without duplication of, the withholding tax described above) at a rate of 30% on payments of dividends on the Company

common stock and sales or redemption proceeds from dispositions of the Company common stock to certain foreign financial institutions (which is broadly defined for this purpose and in general includes investment vehicles) and certain non-financial foreign entities unless various U.S. information reporting and due diligence requirements (generally relating to ownership by U.S. persons of interests in or accounts with those entities) have been satisfied, or an exemption applies. An intergovernmental agreement between the United States and an applicable foreign country, or future Treasury regulations, may modify these requirements. Accordingly, the entity through which shares of the Company common stock are held will affect the determination of whether such withholding is required. Proposed U.S. Treasury regulations would eliminate the requirements under FATCA in respect of withholding on gross proceeds from sales, exchanges or dispositions of our common stock, and the preamble to the proposed regulations provides that taxpayers may rely on these proposed regulations pending their finalization.

The foregoing summary of certain U.S. federal income tax consequences is included for general information only and does not constitute legal advice to any stockholder. The tax consequences of the Dissolution may vary depending upon the particular circumstances of the stockholder. Each stockholder is recommended to consult his or her own tax advisor regarding the tax consequences of the Dissolution.

THE COMPANY INFORMS STOCKHOLDERS THAT (1) ANY DISCUSSION OF U.S. FEDERAL INCOME TAX ISSUES CONTAINED IN THIS PROXY STATEMENT (INCLUDING ANY ATTACHMENTS), UNLESS OTHERWISE SPECIFICALLY STATED, WAS NOT INTENDED OR WRITTEN TO BE USED, AND CANNOT BE USED, FOR THE PURPOSE OF AVOIDING PENALTIES UNDER THE CODE, (2) SUCH DISCUSSION WAS WRITTEN TO SUPPORT THE PROMOTION OR MARKETING OF THE MATTERS ADDRESSED BY THIS PROXY STATEMENT AND (3) EACH STOCKHOLDER SHOULD SEEK ADVICE BASED UPON ITS PARTICULAR CIRCUMSTANCES FROM AN INDEPENDENT TAX ADVISOR.

The following table sets forth the amount of common stock of the Company beneficially owned, directly or indirectly, as of June 4, 2025, by (i) each current director of the Company, (ii) each named executive officer of the Company, (iii) all directors and executive officers of the Company as a group, and (iv) each person who is known to the Company to beneficially own more than five percent (5%) of the outstanding shares of common stock of the Company, as determined through SEC filings and the Company’s records, and the percentage of the common stock outstanding represented by each such amount. All shares of common stock shown in the table reflect sole voting and investment power except as otherwise noted.

Beneficial ownership is determined by the rules of the SEC and includes voting or investment power of the securities. As of June 4, 2025, the Company had 9,797,818 shares of common stock outstanding. Shares of common stock subject to options to purchase, which are now exercisable or are exercisable, or restricted stock units vesting within 60 days after June 4, 2025 are to be considered outstanding for purposes of computing the percentage ownership of the persons holding these options or other rights but are not to be considered outstanding for the purpose of computing the percentage ownership of any other person. Unless otherwise indicated, the address for each person listed below is c/o HOOKIPA Pharma Inc, 350 Fifth Avenue, 72nd Floor, Suite 7240, New York, New York 10118, +43 1 890 63 60.

We are a clinical-stage biopharmaceutical company developing a new class of immunotherapeutics based on our proprietary arenavirus platform that is designed to target and amplify T cell and immune responses to fight diseases. Our replicating and non-replicating technologies are engineered to induce robust and durable antigen-specific CD8+ T cell responses and pathogen-neutralizing antibodies. We believe that our technologies can meaningfully leverage the human immune system for therapeutic purposes by inducing CD8+ T cell response levels previously not achieved by other immune therapy approaches.

Until recently, we were building a proprietary immuno-oncology pipeline utilizing our replicating technology. Our oncology portfolio targets oncoviral cancer antigens and next-generation antigens and includes two primary programs:

We also have a third oncology program, HB-300, targeting self-antigens for the treatment of prostate cancer, which the Company paused further development in January 2024, to conserve capital and ensure pipeline success and operational efficiency.

Additionally, we are developing infectious disease therapies in partnership with other companies. Our HB-400 Program and our HB-500 Program are being developed in a partnership with Gilead. Both Programs are in Phase 1 clinical development.

The SEC has adopted rules that permit companies and intermediaries (e.g., brokers) to satisfy the delivery requirements for Special Meeting materials with respect to two or more stockholders sharing the same address by delivering a single set of Special Meeting materials addressed to those stockholders. This process, which is commonly referred to as “householding,” potentially means extra convenience for stockholders and cost savings for companies.

This year, a number of brokers with account holders who are stockholders will be “householding” our proxy materials. A single set of Special Meeting materials will be delivered to multiple stockholders sharing an address unless contrary instructions have been received from the affected stockholders. Once you have received notice from your broker that they will be “householding” communications to your address, “householding” will continue until you are notified otherwise or until you revoke your consent. If, at any time, you no longer wish to participate in “householding” and would prefer to receive a separate set of Special Meeting materials, please notify your broker, bank or other nominee, or the Company at: HOOKIPA Pharma Inc., 350 Fifth Avenue, 72nd Floor, Suite 7240, New York, New York 10118, +43 1 890 63 60, Attention: Corporate Secretary, and the Company will deliver those documents to such stockholder promptly upon receiving the request. Stockholders who currently receive multiple copies of the Special Meeting materials at their addresses and would like to request “householding” of their communications should contact their brokers.

Our common stock is listed on Nasdaq under the symbol “HOOK.” As of June 17, 2025, there were 9,799,053 shares of common stock outstanding and one holder of record of shares of our common stock and two holders of record of shares of our Class A common stock. The actual number of stockholders is greater than this number of record holders and includes stockholders who are beneficial owners, but whose shares are held in street name by banks, brokers and other nominees.

On    , 2025, the latest practicable trading day before the printing of this proxy statement, the closing price for our common stock on Nasdaq was $    per share. You are encouraged to obtain current market prices for our common stock.

Following the Dissolution, there will be no further market for our common stock, and it will be delisted from Nasdaq prior to the Dissolution and deregistered under the Exchange Act. As a result, following the Dissolution, we will no longer file periodic reports under the Exchange Act with the SEC.

We have never declared or paid any cash dividends on our common stock. In the event that the Dissolution is not consummated, our payment of any future dividends would be at the discretion of our Board and will depend on then-existing conditions, including our financial condition, operating results, contractual restrictions, capital requirements, business prospects, and other factors our Board may deem relevant.

In the event that we hold the 2025 annual meeting of stockholders, the Bylaws provide that, for nominations of persons for election to our Board or other proposals to be considered at an annual meeting of our stockholders, a stockholder must give written notice to our corporate secretary at HOOKIPA Pharma Inc., 350 Fifth Avenue, 72nd Floor, New York, New York 10118, not later than the close of business 90 days, nor earlier than the close of business 120 days, prior to the first anniversary of the date of the preceding year’s annual meeting. However, the Bylaws also provide that in the event that the date of the annual meeting is more than 30 days before or more than 60 days after such anniversary date, notice must be delivered not later than the close of business on the later of the 90th day prior to such annual meeting or the 10th day following the day on which public announcement of the date of such meeting is first made. Any such notice must also comply with the requirements set forth in the Bylaws.

For stockholder proposals and nominations to be brought before the 2025 annual meeting of stockholders (if one is held), the required notice was required to be received by our corporate secretary at our principal executive offices no earlier than the close of business on February 17, 2025 and no later than the close of business on March 19, 2025; provided, however, that if our 2025 annual meeting of stockholders is held after August 16, 2025, then the proposal must be delivered not later than the close of business on the later of the 90th day prior to such annual meeting or the 10th day following the day on which public announcement of the date of such meeting is first made. The Bylaws specify the requirements as to form and content of all stockholders’ notices. These requirements may preclude stockholders from bringing matters before the stockholders at an annual or special meeting.

In addition, stockholders who intend to solicit proxies in support of director nominees other than our nominees must provide in their notice any additional information required by Rule 14a-19(b) under the Exchange Act.

In addition to the requirements stated above, any stockholder who wishes to submit a proposal for inclusion in our proxy materials in connection with an annual meeting (if one is held) must comply with Rule 14a-8 promulgated under the Exchange Act. For such proposals to be included in our proxy materials relating to our 2025 annual meeting of stockholders, all applicable requirements of Rule 14a-8 must be satisfied and we must have received such proposals no later than December 27, 2024; provided, however, that if our 2025 annual meeting of stockholders is held after August 16, 2025, then the deadline is a reasonable amount of time prior to the date we begin to print and mail our proxy statement for the 2025 annual meeting of stockholders. Such proposals must be delivered to our corporate secretary at HOOKIPA Pharma Inc., 350 Fifth Avenue, 72nd Floor, Suite 7240, New York, New York 10118.

We have not authorized anyone to provide you with information that is different from what is contained in this proxy statement, the annexes to this proxy statement, any amendments or supplements to this proxy statements, and the documents that we incorporate by reference into this proxy statement. We take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. This proxy statement is dated   , 2025. You should not assume that the information contained in this proxy statement is accurate as of any date other than that date (or as of an earlier date if so indicated in this proxy statement), and the mailing of this proxy statement to stockholders does not create any implication to the contrary. This proxy statement does not constitute a solicitation of a proxy in any jurisdiction where, or to or from any person to whom, it is unlawful to make a proxy solicitation.

We file annual, quarterly and current reports, proxy statements and other information with the SEC. Our SEC filings are available to the public at the SEC website at www.sec.gov. You also may obtain free copies of the documents we file with the SEC, including this proxy statement, by going to the investor relations page of our website at https://ir.hookipapharma.com/. Our website address is provided as an inactive textual reference only. The information provided on, or accessible through, our website is not part of this proxy statement, and therefore is not incorporated herein by reference.

The SEC allows us to “incorporate by reference” information into this proxy statement, which means that we can disclose important information to you by referring you to other documents filed separately with the SEC. The information incorporated by reference is deemed to be part of this proxy statement, except for any information superseded by information in this proxy statement or incorporated by reference subsequent to the date of this proxy statement. This proxy statement incorporates by reference the documents set forth below that we have previously filed with the SEC.

We also incorporate by reference into this proxy statement additional documents that we may file with the SEC under Section 13(a), 13(c), 14 or 15(d) of the Exchange Act (in each case, other than those documents or the portions of those documents not deemed to be filed) between the date of this proxy statement and the earlier of the date of the Special Meeting or the termination of the Plan of Dissolution. These documents include periodic reports, such as Annual Reports on Form 10-K and Quarterly Reports on Form 10-Q, as well as Current Reports on Form 8-K and proxy soliciting materials.

Notwithstanding the foregoing, we will not incorporate by reference in this proxy statement any documents or portions thereof that are not deemed “filed” with the SEC, including information furnished under Item 2.02 or Item 7.01 or otherwise of any Current Report on Form 8-K, including related exhibits, after the date of this proxy statement unless, and except to the extent, specified in such Current Report.

HOOKIPA’s SEC filings are available to the public over the Internet at the SEC’s website at www.sec.gov.

Any person, including any beneficial owner of shares of HOOKIPA common stock, to whom this proxy statement is delivered may request copies of proxy statements and any of the documents incorporated by reference in this document or other information concerning us by written or telephonic request directed to HOOKIPA’s address below. If you would like to request documents from us, please do so as soon as possible, to receive them before the Special Meeting. If you request any documents from us, we will mail them to you by first class mail, or another equally prompt method, within one business day after we receive your request. Documents incorporated by reference are available without charge, excluding any exhibits to those documents unless the exhibit is specifically incorporated by reference into those documents.

Our Board of Directors knows of no other matters to be presented for consideration at the Special Meeting.