Amendment: SEC Form SCHEDULE 13D/A filed by Zenas BioPharma Inc.

The address of each Reporting Person for purposes of this filing is: c/o SR One Capital Management, LP, 985 Old Eagle School Road, Suite 511, Wayne, PA 19087.

The principal business of the Funds is to invest in and assist growth-oriented businesses. The principal business of SR One Partners II is to act as the sole general partner of SR One Fund II Aggregator. The principal business of SMA Partners is to act as the sole general partner of AMZL. The principal business of SR One Opportunities Partners I is to act as the sole general partner of SR One Opportunities Fund I. The principal business of SR One Capital Management is to act as the sole general partner of SR One Partners II, SMA Partners, SR One Opportunities Partners I and a number of affiliated partnerships with similar businesses. The principal business of Dr. George is to manage SR One Capital Management.

During the five years prior to the date hereof, none of the Reporting Persons has been convicted in a criminal proceeding or has been a party to a civil proceeding ending in a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.

During the five years prior to the date hereof, none of the Reporting Persons has been convicted in a criminal proceeding or has been a party to a civil proceeding ending in a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.

SR One Fund II Aggregator, SR One Partners II, AMZL, SMA Partners, SR One Opportunities Fund I, and SR One Opportunities Partners I are limited partnerships organized under the laws of the State of Delaware. SR One Capital Management is a limited liability company organized under the laws of the State of Delaware. Dr. George is a United States citizen.

On October 7, 2025, the Issuer entered into a securities purchase agreement (the "Securities Purchase Agreement") with (i) certain institutional and accredited investors (the "Institutional Investors") and (ii) certain directors and officers of the Issuer (the "Director and Officer Investors"), pursuant to which the Issuer agreed to sell to (i) the Institutional Investors an aggregate of 6,261,112 shares of Common Stock at a price of $19.00 per share, and (ii) the Director and Officer Investors an aggregate of 48,918 shares of Common Stock at a price of $20.85 per share, in each case in a private placement transaction (the "Private Placement"). The Private Placement closed on October 9, 2025. Pursuant to the Securities Purchase Agreement, SR One Opportunities Fund I purchased 63,158 shares of Common Stock for an aggregate purchase price of $1,200,002.00. SR One Opportunities Fund I now beneficially owns a total of 1,173,395 shares of Common Stock (the "SR One Opportunities Fund I Shares"). The working capital of SR One Opportunities Fund I is the source of the funds for the purchase of the SR One Opportunities Fund I Shares. No part of the purchase price of the SR One Opportunities Fund I Shares is represented by funds or other consideration borrowed or otherwise obtained for the purpose of acquiring, holding, trading or voting the SR One Opportunities Fund I Shares. Pursuant to the Securities Purchase Agreement, AMZL purchased 63,157 shares of Common Stock for an aggregate purchase price of $1,199,983.00. AMZL now beneficially owns a total of 1,917,895 shares of Common Stock (the "AMZL Shares"). The working capital of AMZL is the source of the funds for the purchase of the AMZL Shares. No part of the purchase price of the AMZL Shares is represented by funds or other consideration borrowed or otherwise obtained for the purpose of acquiring, holding, trading or voting the AMZL Shares. Collectively, the Funds now beneficially own a total of 5,037,854 shares of Common Stock (the "Fund Shares"). The shares of Common Stock issued in the Private Placement were issued in a private placement exempt from the registration requirements of the Securities Act of 1933, as amended (the "Securities Act"), and have not been registered under the Securities Act. The foregoing description of the Securities Purchase Agreement does not purport to be complete and is qualified in its entirety by reference to the full text of the form of Securities Purchase Agreement, a copy of which is attached as Exhibit 10.3 to the Issuer's Form 8-K filed with the Securities and Exchange Commission (the "SEC") on October 8, 2025 (the "Form 8-K") and incorporated by reference herein.

The Funds acquired their respective shares for investment purposes. Depending on market conditions, their continuing evaluation of the business and prospects of the Issuer and other factors, the Funds and other Reporting Persons may dispose of or acquire additional shares of the Issuer. Except as set forth above, none of the Reporting Persons has any present plans which relate to or would result in: (a) The acquisition by any person of additional securities of the Issuer, or the disposition of securities of the Issuer; (b) An extraordinary corporate transaction, such as a merger, reorganization or liquidation, involving the Issuer or any of its subsidiaries; (c) A sale or transfer of a material amount of assets of the Issuer or any of its subsidiaries; (d) Any change in the present board of directors or management of the Issuer, including any plans or proposals to change the number or term of directors or to fill any existing vacancies on the board; (e) Any material change in the present capitalization or dividend policy of the Issuer; (f) Any other material change in the Issuer's business or corporate structure; (g) Changes in the Issuer's charter, bylaws or instruments corresponding thereto or other actions which may impede the acquisition of control of the Issuer by any person; (h) Causing a class of securities of the Issuer to be delisted from a national securities exchange or to cease to be authorized to be quoted in an inter-dealer quotation system of a registered national securities association; (i) A class of equity securities of the Issuer becoming eligible for termination of registration pursuant to Section 12(g)(4) of the Securities Exchange Act of 1934; or (j) Any action similar to any of those enumerated above.

SR One Fund II Aggregator is the record owner of the SR One Fund II Aggregator Shares. As the general partner of SR One Fund II Aggregator, SR One Partners II may be deemed to beneficially own the SR One Fund II Aggregator Shares. As the general partner of SR One Partners II, SR One Capital Management may be deemed to beneficially own the SR One Fund II Aggregator Shares. As the managing member of SR One Capital Management, Dr. George may be deemed to beneficially own the SR One Fund II Aggregator Shares. AMZL is the record owner of the AMZL Shares. As the general partner of AMZL, SMA Partners may be deemed to beneficially own the AMZL Shares. As the general partner of SMA Partners, SR One Capital Management may be deemed to beneficially own the AMZL Shares. As the managing member of SR One Capital Management, Dr. George may be deemed to beneficially own the AMZL Shares. SR One Opportunities Fund I is the record owner of the SR One Opportunities Fund I Shares. As the general partner of SR One Opportunities Fund I, SR One Opportunities Partners I may be deemed to beneficially own the SR One Opportunities Fund I Shares. As the general partner of SR One Opportunities Partners I, SR One Capital Management may be deemed to beneficially own the SR One Opportunities Fund I Shares. As the managing member of SR One Capital Management, Dr. George may be deemed to beneficially own the SR One Opportunities Fund I Shares. Each Reporting Person disclaims beneficial ownership of the Fund Shares other than those shares which such person owns of record. The percentage of outstanding shares of Common Stock which may be deemed to be beneficially owned by each Reporting Person is set forth on Line 13 of such Reporting Person's cover sheet. Such percentage was calculated based on 53,420,343 shares of Common Stock, which includes the sum of (i) 42,110,313 shares of Common Stock reported by the Issuer to be outstanding as of July 31, 2025, on the Issuer's Form 10-Q filed with the SEC on August 12, 2025, (ii) 6,310,030 shares of Common Stock sold by the Issuer in the Private Placement, and (iii) 5,000,000 shares of Common Stock sold to InnoCare Pharma Inc. on October 7, 2025 as reported in the Form 8-K.

(i) sole power to vote or to direct the vote: See line 7 of cover sheets (ii) shared power to vote or to direct the vote: See line 8 of cover sheets (iii) sole power to dispose or to direct the disposition: See line 9 of cover sheets (iv) shared power to dispose or to direct the disposition: See line 10 of cover sheets

Except as set forth in Item 3 above, none of the Reporting Persons has effected any transaction in shares of Common Stock during the last 60 days.

No other person is known to have the right to receive or the power to direct the receipt of dividends from, or any proceeds from the sale of, Common Stock beneficially owned by any of the Reporting Persons.

Not applicable.

SR One Opportunities Fund I and AMZL entered into the Securities Purchase Agreement and a Registration Rights Agreement on October 7, 2025, in each case, as further described in the Form 8-K, the descriptions of which are incorporated by reference herein.

Exhibit 1 - Agreement regarding filing of joint Schedule 13D. Exhibit 2 - Power of Attorney regarding filings under the Securities Exchange Act of 1934, as amended.