• Live Feeds
    • Press Releases
    • Insider Trading
    • FDA Approvals
    • Analyst Ratings
    • Insider Trading
    • SEC filings
    • Market insights
  • Analyst Ratings
  • Alerts
  • Subscriptions
  • Settings
  • RSS Feeds
Quantisnow Logo
  • Live Feeds
    • Press Releases
    • Insider Trading
    • FDA Approvals
    • Analyst Ratings
    • Insider Trading
    • SEC filings
    • Market insights
  • Analyst Ratings
  • Alerts
  • Subscriptions
  • Settings
  • RSS Feeds
PublishGo to App
    Quantisnow Logo

    © 2026 quantisnow.com
    Democratizing insights since 2022

    Services
    Live news feedsRSS FeedsAlertsPublish with Us
    Company
    AboutQuantisnow PlusContactJobsAI superconnector for talent & startupsNEWLLM Arena
    Legal
    Terms of usePrivacy policyCookie policy

    SEC Form SC 13G/A filed by Prothena Corporation plc (Amendment)

    2/2/24 2:18:06 PM ET
    $PRTA
    Biotechnology: Pharmaceutical Preparations
    Health Care
    Get the next $PRTA alert in real time by email
    SC 13G/A 1 ie00b91xrn20_020224.txt ie00b91xrn20_020224.txt SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No: 9) PROTHENA CORPORATION PUBLIC LIMITED COMPANY -------------------------------------------------------- (Name of Issuer) Common Stock -------------------------------------------------------- (Title of Class of Securities) B91XRN2 -------------------------------------------------------- (SEDOL Number) December 31, 2023 -------------------------------------------------------- (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Schedule is filed: [X] Rule 13d-1(b) [ ] Rule 13d-1(c) [ ] Rule 13d-1(d) *The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page. The information required in the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes). SEDOL No. B91XRN2 (1)Names of reporting persons. BlackRock, Inc. (2) Check the appropriate box if a member of a group (a) [ ] (b) [X] (3) SEC use only (4) Citizenship or place of organization Delaware Number of shares beneficially owned by each reporting person with: (5) Sole voting power 3684648 (6) Shared voting power 0 (7) Sole dispositive power 3770650 (8) Shared dispositive power 0 (9) Aggregate amount beneficially owned by each reporting person 3770650 (10) Check if the aggregate amount in Row (9) excludes certain shares (11) Percent of class represented by amount in Row 9 7.0% (12) Type of reporting person HC Item 1. Item 1(a) Name of issuer: ----------------------------------------------------------------------- PROTHENA CORPORATION PUBLIC LIMITED COMPANY Item 1(b) Address of issuer's principal executive offices: ----------------------------------------------------------------------- 77 Sir John Rogerson's Quay, Block C Grand Canal Docklands DUBLIN 2 Ireland D02 VK60 Item 2. 2(a) Name of person filing: ---------------------------------------------------------------------- BlackRock, Inc. 2(b) Address or principal business office or, if none, residence: ----------------------------------------------------------------------- BlackRock, Inc. 50 Hudson Yards New York, NY 10001 2(c) Citizenship: -------------------------------------------------------------------- See Item 4 of Cover Page 2(d) Title of class of securities: ------------------------------------------------------------------- Common Stock 2(e) SEDOL No.: See Cover Page Item 3. If this statement is filed pursuant to Rules 13d-1(b), or 13d-2(b) or (c), check whether the person filing is a: [ ] Broker or dealer registered under Section 15 of the Act; [ ] Bank as defined in Section 3(a)(6) of the Act; [ ] Insurance company as defined in Section 3(a)(19) of the Act; [ ] Investment company registered under Section 8 of the Investment Company Act of 1940; [ ] An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E); [ ] An employee benefit plan or endowment fund in accordance with Rule 13d-1(b)(1)(ii)(F); [X] A parent holding company or control person in accordance with Rule 13d-1(b)(1)(ii)(G); [ ] A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813); [ ] A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940; [ ] A non-U.S. institution in accordance with Rule 240.13d-1(b)(1)(ii)(J); [ ] Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K). If filing as a non-U.S. institution in accordance with Rule 240.13d-1(b)(1)(ii)(J), please specify the type of institution: Item 4. Ownership Provide the following information regarding the aggregate number and percentage of the class of securities of the issuer identified in Item 1. Amount beneficially owned: 3770650 Percent of class 7.0% Number of shares as to which such person has: Sole power to vote or to direct the vote 3684648 Shared power to vote or to direct the vote 0 Sole power to dispose or to direct the disposition of 3770650 Shared power to dispose or to direct the disposition of 0 Item 5. Ownership of 5 Percent or Less of a Class. If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than 5 percent of the class of securities, check the following [ ]. Item 6. Ownership of More than 5 Percent on Behalf of Another Person If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required. Various persons have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of the common stock of PROTHENA CORPORATION PUBLIC LIMITED COMPANY. No one person's interest in the common stock of PROTHENA CORPORATION PUBLIC LIMITED COMPANY is more than five percent of the total outstanding common shares. Item 7. Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person. See Exhibit A Item 8. Identification and Classification of Members of the Group If a group has filed this schedule pursuant to Rule 13d-1(b)(ii)(J), so indicate under Item 3(j) and attach an exhibit stating the identity and Item 3 classification of each member of the group. If a group has filed this schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating the identity of each member of the group. Item 9. Notice of Dissolution of Group Notice of dissolution of a group may be furnished as an exhibit stating the date of the dissolution and that all further filings with respect to transactions in the security reported on will be filed, if required, by members of the group, in their individual capacity. See Item 5. Item 10. Certifications By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect. Signature. After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct. Dated: February 2, 2024 BlackRock, Inc. Signature: Spencer Fleming ------------------------------------------- Name/Title Attorney-In-Fact The original statement shall be signed by each person on whose behalf the statement is filed or his authorized representative. If the statement is signed on behalf of a person by his authorized representative other than an executive officer or general partner of the filing person, evidence of the representative's authority to sign on behalf of such person shall be filed with the statement, provided, however, that a power of attorney for this purpose which is already on file with the Commission may be incorporated by reference. The name and any title of each person who signs the statement shall be typed or printed beneath his signature. Attention: Intentional misstatements or omissions of fact constitute Federal criminal violations (see 18 U.S.C. 1001). Exhibit A Subsidiary BlackRock Life Limited BlackRock Advisors, LLC Aperio Group, LLC BlackRock (Netherlands) B.V. BlackRock Institutional Trust Company, National Association BlackRock Asset Management Ireland Limited BlackRock Financial Management, Inc. BlackRock Japan Co., Ltd. BlackRock Asset Management Schweiz AG BlackRock Investment Management, LLC BlackRock Investment Management (UK) Limited BlackRock Asset Management Canada Limited BlackRock Investment Management (Australia) Limited BlackRock Fund Advisors BlackRock Fund Managers Ltd *Entity beneficially owns 5% or greater of the outstanding shares of the security class being reported on this Schedule 13G. Exhibit B POWER OF ATTORNEY The undersigned, BlackRock, Inc., a corporation duly organized under the laws of the State of Delaware, United States (the "Company"), does hereby make, constitute and appoint each of Eric Andruczyk, Richard Cundiff, R. Andrew Dickson, III, Spencer Fleming, Daniel Goldmintz, Laura Hildner, Elizabeth Kogut, David Maryles, Christopher Meade, Una Neary, Charles Park, Daniel Riemer, David Rothenberg and Brenda Schulz, acting severally, as its true and lawful attorneys-in-fact, for the purpose of, from time to time, executing, in its name and on its behalf and on behalf of its direct and indirect subsidiaries, any and all documents, certificates, instruments, statements, filings, agreements and amendments (collectively, "documents") determined by such person to be necessary or appropriate to comply with ownership or control-person reporting requirements imposed by any United States or non-United States governmental or regulatory authority, including, without limitation, Schedules 13D and 13G and Forms 3, 4, 5, 13F and 13H and any amendments to any of the foregoing as may be required to be filed with the Securities and Exchange Commission, and delivering, furnishing or filing any such documents with the appropriate governmental or regulatory authority or other person, and giving and granting to each such attorney-in-fact full power and authority to do and perform any and every act and thing whatsoever requisite, necessary or proper to be done in the exercise of any of the rights and powers herein granted, as fully and to all intents and purposes as the Company and/or its direct and indirect subsidiaries, as applicable, might or could do if personally present by one of its authorized signatories, hereby ratifying and confirming all that said attorney-in-fact shall lawfully do or cause to be done by virtue hereof. Any such determination by an attorney-in-fact named herein shall be conclusively evidenced by such person's execution, delivery, furnishing or filing of the applicable document. This power of attorney shall expressly revoke the power of attorney dated 2nd day of January, 2019 in respect of the subject matter hereof, shall be valid from the date hereof and shall remain in full force and effect until either revoked in writing by the Company, or, in respect of any attorney-in-fact named herein, until such person ceases to be an employee of the Company or one of its affiliates. IN WITNESS WHEREOF, the undersigned has caused this power of attorney to be executed as of this 30th day of April, 2023. BlackRock, Inc. By: /s/ R. Andrew Dickson, III Name: R. Andrew Dickson, III Title: Corporate Secretary
    Get the next $PRTA alert in real time by email

    Crush Q1 2026 with the Best AI Superconnector

    Stay ahead of the competition with Standout.work - your AI-powered talent-to-startup matching platform.

    AI-Powered Inbox
    Context-aware email replies
    Strategic Decision Support
    Get Started with Standout.work

    Recent Analyst Ratings for
    $PRTA

    DatePrice TargetRatingAnalyst
    5/28/2025$4.00Neutral → Underperform
    BofA Securities
    5/27/2025Outperform → Perform
    Oppenheimer
    5/27/2025$6.00Buy → Hold
    Jefferies
    5/27/2025Overweight → Neutral
    Cantor Fitzgerald
    12/20/2024$40.00Buy
    Chardan Capital Markets
    1/30/2024$68.00 → $38.00Buy → Neutral
    BofA Securities
    12/12/2023$62.00Buy
    Deutsche Bank
    4/24/2023$80.00Outperform
    SVB Securities
    More analyst ratings

    $PRTA
    SEC Filings

    View All

    Prothena Corporation plc filed SEC Form 8-K: Leadership Update, Financial Statements and Exhibits

    8-K - PROTHENA CORP PUBLIC LTD CO (0001559053) (Filer)

    12/12/25 4:26:08 PM ET
    $PRTA
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Prothena Corporation plc filed SEC Form 8-K: Submission of Matters to a Vote of Security Holders, Financial Statements and Exhibits

    8-K - PROTHENA CORP PUBLIC LTD CO (0001559053) (Filer)

    11/19/25 4:30:57 PM ET
    $PRTA
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Amendment: SEC Form SCHEDULE 13G/A filed by Prothena Corporation plc

    SCHEDULE 13G/A - PROTHENA CORP PUBLIC LTD CO (0001559053) (Subject)

    11/12/25 3:47:28 PM ET
    $PRTA
    Biotechnology: Pharmaceutical Preparations
    Health Care

    $PRTA
    Insider Trading

    Insider transactions reveal critical sentiment about the company from key stakeholders. See them live in this feed.

    View All

    Chief Scientific Officer Zago Wagner M. was granted 85,000 units of Ordinary Shares (SEC Form 4)

    4 - PROTHENA CORP PUBLIC LTD CO (0001559053) (Issuer)

    7/30/25 5:52:29 PM ET
    $PRTA
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Chief Accounting Officer Walker Karin L was granted 25,000 units of Ordinary Shares (SEC Form 4)

    4 - PROTHENA CORP PUBLIC LTD CO (0001559053) (Issuer)

    7/30/25 5:52:14 PM ET
    $PRTA
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Chief Development Officer Swanson Chad J. was granted 85,000 units of Ordinary Shares (SEC Form 4)

    4 - PROTHENA CORP PUBLIC LTD CO (0001559053) (Issuer)

    7/30/25 5:52:01 PM ET
    $PRTA
    Biotechnology: Pharmaceutical Preparations
    Health Care

    $PRTA
    Insider Purchases

    Insider purchases reveal critical bullish sentiment about the company from key stakeholders. See them live in this feed.

    View All

    Large owner Scully William P received a gift of 430,000 units of Ordinary Shares, bought $2,749,916 worth of Ordinary Shares (207,436 units at $13.26) and gifted 747,700 units of Ordinary Shares, decreasing direct ownership by 7% to 735,993 units (SEC Form 4)

    4 - PROTHENA CORP PUBLIC LTD CO (0001559053) (Issuer)

    5/2/25 10:29:05 AM ET
    $PRTA
    Biotechnology: Pharmaceutical Preparations
    Health Care

    $PRTA
    Analyst Ratings

    Analyst ratings in real time. Analyst ratings have a very high impact on the underlying stock. See them live in this feed.

    View All

    Prothena downgraded by BofA Securities with a new price target

    BofA Securities downgraded Prothena from Neutral to Underperform and set a new price target of $4.00

    5/28/25 8:10:50 AM ET
    $PRTA
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Prothena downgraded by Oppenheimer

    Oppenheimer downgraded Prothena from Outperform to Perform

    5/27/25 9:09:16 AM ET
    $PRTA
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Prothena downgraded by Jefferies with a new price target

    Jefferies downgraded Prothena from Buy to Hold and set a new price target of $6.00

    5/27/25 9:09:16 AM ET
    $PRTA
    Biotechnology: Pharmaceutical Preparations
    Health Care

    $PRTA
    Press Releases

    Fastest customizable press release news feed in the world

    View All

    Prothena Announces Board of Directors Update

    Prothena Corporation plc (NASDAQ:PRTA), a late-stage clinical biotechnology company with a robust pipeline of investigational therapeutics built on protein dysregulation expertise, today announced that Paula Cobb will step down from Prothena's Board of Directors to join Manifold Bio as its Chief Operating Officer. During her six-year tenure, Ms. Cobb played a significant role in which she made key contributions to the Company's vision and strategy. "I would like to thank Paula for her many contributions during the past six years. As a biotechnology executive with wide-ranging global development, business strategy and commercial expertise, she provided valuable insights to the board and lea

    12/12/25 4:05:00 PM ET
    $PRTA
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Prothena Announces Poster Presentation on its TDP-43 CYTOPE® Program at Neuroscience 2025

    TDP-43 CYTOPE® preclinical data demonstrates the potential of Prothena's CYTOPE technology as a novel modality for delivering large molecules into cells, enabling precise targeting of intracellular disease pathways Systemically-administered TDP-43 CYTOPE rapidly and efficiently distributed to the brain and periphery, internalized into the cytosol and significantly reduced intracellular TDP-43 pathology in an ALS mouse model TDP-43 CYTOPE meaningfully reduced intracellular TDP-43 pathology and associated RNA dysregulation caused by cryptic exon inclusions - key pathogenic features of TDP-43 proteinopathies - in a human-derived neuronal cell line   Prothena Corporation plc (NASDAQ

    11/19/25 4:05:00 PM ET
    $PRTA
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Prothena Highlights Phase 2 Data for Coramitug (Formerly PRX004) Published in Circulation, Official Journal of AHA

    Novo Nordisk's Phase 2 data for coramitug supports ongoing Phase 3 CLEOPATTRA clinical trial in patients with ATTR amyloidosis with cardiomyopathy Coramitug is being developed by Novo Nordisk as part of their up to $1.2 billion acquisition of Prothena's ATTR amyloidosis business and pipeline Prothena Corporation plc (NASDAQ:PRTA) announced the publication of Phase 2 clinical trial data for coramitug (formerly PRX004), a potential first-in-class amyloid depleter antibody, for the treatment of ATTR amyloidosis with cardiomyopathy (ATTR-CM), in the American Heart Association's journal, Circulation. A link to the online publication can be found here: Coramitug, a Humanized Monoclonal

    11/11/25 9:00:00 AM ET
    $PRTA
    Biotechnology: Pharmaceutical Preparations
    Health Care

    $PRTA
    Leadership Updates

    Live Leadership Updates

    View All

    Prothena Announces Board of Directors Update

    Prothena Corporation plc (NASDAQ:PRTA), a late-stage clinical biotechnology company with a robust pipeline of investigational therapeutics built on protein dysregulation expertise, today announced that Paula Cobb will step down from Prothena's Board of Directors to join Manifold Bio as its Chief Operating Officer. During her six-year tenure, Ms. Cobb played a significant role in which she made key contributions to the Company's vision and strategy. "I would like to thank Paula for her many contributions during the past six years. As a biotechnology executive with wide-ranging global development, business strategy and commercial expertise, she provided valuable insights to the board and lea

    12/12/25 4:05:00 PM ET
    $PRTA
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Prothena Reports Third Quarter 2024 Financial Results and Business Highlights

    Net cash used in operating and investing activities was $45.2 million and $102.5 million for the third quarter and first nine months of 2024, respectively; quarter-end cash and restricted cash position was $520.1 million PRX012, a potential single-injection once-monthly subcutaneous treatment, is designed to address the unmet need of millions of patients with presymptomatic or early symptomatic Alzheimer's disease; Prothena expects to report multiple clinical readouts starting in mid-2025 and continuing throughout the year from the ongoing Phase 1 ASCENT clinical trials Results from partner Roche evaluating prasinezumab in patients with early Parkinson's disease from the Phase 2 PASA

    11/12/24 4:05:00 PM ET
    $PRTA
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Prothena Reports First Quarter 2024 Financial Results and Business Highlights

    Net cash used in operating and investing activities was $73.2 million in the first quarter of 2024; quarter-end cash and restricted cash position was $548.7 million Advanced potential best-in-class Alzheimer's disease portfolio: initial data supportive of ongoing Phase 1 clinical trial for PRX012, an anti-amyloid beta antibody; received FDA clearance for IND application and Fast Track designation for PRX123, a dual amyloid beta/tau vaccine; Phase 2 clinical trial initiated in patients with early Alzheimer's disease for BMS-986446 (formerly PRX005) by partner Bristol Myers Squibb Strengthened leadership position in the amyloidosis community with ongoing enrollment of the confirmatory

    5/8/24 4:05:00 PM ET
    $PRTA
    Biotechnology: Pharmaceutical Preparations
    Health Care

    $PRTA
    Large Ownership Changes

    This live feed shows all institutional transactions in real time.

    View All

    Amendment: SEC Form SC 13G/A filed by Prothena Corporation plc

    SC 13G/A - PROTHENA CORP PUBLIC LTD CO (0001559053) (Subject)

    11/14/24 1:22:34 PM ET
    $PRTA
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Amendment: SEC Form SC 13G/A filed by Prothena Corporation plc

    SC 13G/A - PROTHENA CORP PUBLIC LTD CO (0001559053) (Subject)

    11/13/24 7:00:50 AM ET
    $PRTA
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Amendment: SEC Form SC 13G/A filed by Prothena Corporation plc

    SC 13G/A - PROTHENA CORP PUBLIC LTD CO (0001559053) (Subject)

    11/13/24 6:06:27 AM ET
    $PRTA
    Biotechnology: Pharmaceutical Preparations
    Health Care

    $PRTA
    Financials

    Live finance-specific insights

    View All

    Prothena to Report Third Quarter 2025 Financial Results on November 6

    Prothena Corporation plc (NASDAQ:PRTA), a late-stage clinical biotechnology company with a robust pipeline of investigational therapeutics built on protein dysregulation expertise, today announced that it will report its third quarter and first nine months of 2025 financial results on Thursday November 6, 2025, after the close of the U.S. financial markets. Consistent with past practice, the Company will not be conducting a conference call in conjunction with the financial results release on November 6. About Prothena Prothena Corporation plc is a late-stage clinical biotechnology company with expertise in protein dysregulation and a pipeline of investigational therapeutics with the p

    10/30/25 4:05:00 PM ET
    $PRTA
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Prothena to Report Second Quarter 2025 Financial Results on August 4

    Prothena Corporation plc (NASDAQ:PRTA), a late-stage clinical biotechnology company with a robust pipeline of investigational therapeutics built on protein dysregulation expertise, today announced that it will report its second quarter and first six months of 2025 financial results on Monday, August 4, 2025, after the close of the U.S. financial markets. Consistent with past practice, the Company will not be conducting a conference call in conjunction with the financial results release on August 4. About Prothena Prothena Corporation plc is a late-stage clinical biotechnology company with expertise in protein dysregulation and a pipeline of investigational therapeutics with the potent

    7/28/25 4:05:00 PM ET
    $PRTA
    Biotechnology: Pharmaceutical Preparations
    Health Care

    Prothena to Report First Quarter 2025 Financial Results on May 8

    Prothena Corporation plc (NASDAQ:PRTA), a late-stage clinical biotechnology company with a robust pipeline of investigational therapeutics built on protein dysregulation expertise, today announced that it will report its first quarter 2025 financial results on Thursday, May 8, 2025, after the close of the U.S. financial markets. Consistent with past practice, the Company will not be conducting a conference call in conjunction with the financial results release on May 8. About Prothena Prothena Corporation plc is a late-stage clinical biotechnology company with expertise in protein dysregulation and a pipeline of investigational therapeutics with the potential to change the course of deva

    5/1/25 4:05:00 PM ET
    $PRTA
    Biotechnology: Pharmaceutical Preparations
    Health Care