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ZBIO Form 4: Director-linked funds acquire 321,983 shares

Filing Impact
(Very High)
Filing Sentiment
(Very Positive)
Form Type
4

Rhea-AI Filing Summary

Director Hongbo Lu reported purchases of Zenas BioPharma (ZBIO) common stock totaling 321,983 shares held indirectly through NextBio entities. The Form 4 shows two non-derivative acquisitions: 58,823 shares bought on 09/13/2024 at $17 per share and 263,160 shares bought on 10/07/2025 at $19 per share, bringing indirect beneficial ownership to 321,983 shares. The filing clarifies these shares are owned directly by NextBio Master Fund LP and NextBio Evergreen LLC and may be deemed indirectly owned by NextBio Capital entities and Mr. Lu in his capacity as a managing member; the reporting person disclaims direct beneficial ownership except for pecuniary interest. The statement is a routine Section 16 disclosure of insider transactions and shows increased insider-aligned position through affiliated investment vehicles.

Positive

  • Insider-aligned increase: Indirect holdings rose to 321,983 shares after two purchases
  • Transparent disclosure: Transactions reported on Form 4 with specific dates and prices ($17 and $19)

Negative

  • None.

Insights

Large affiliated purchases increase indirect insider stake to 321,983 shares.

The disclosed transactions are two non-derivative acquisitions: $17 x 58,823 shares on 09/13/2024 and $19 x 263,160 shares on 10/07/2025, reported as indirect holdings through NextBio entities. The structure indicates the economic interest sits with investment vehicles rather than direct personal ownership.

Primary dependencies are the fund ownership structures and reporting accuracy; risks are limited to typical disclosure timing and filing classification. Monitor future Form 4s for further purchases or dispositions by the same reporting group within the next 12 months to track any change in aligned ownership.

Report clarifies governance role and disclaimers on beneficial ownership.

The filing identifies the reporting person as a Director and explains indirect ownership through NEXTBio Master Fund LP and NextBio Evergreen LLC, naming NextBio Capital entities and Hongbo Lu as managing members. The standard disclaimer limits admission of beneficial ownership beyond pecuniary interest.

This disclosure is material for assessing potential alignment between management/directors and external investors; consider reviewing the issuer's outstanding share count and future Schedule 13D/G filings within 12 months to evaluate the ownership stake's influence.

Insider Lu Hongbo
Role Director
Bought 321,983 shs ($6.00M)
Type Security Shares Price Value
Purchase Common Stock 263,160 $19.00 $5.00M
Purchase Common Stock 58,823 $17.00 $1000K
Holdings After Transaction: Common Stock — 321,983 shares (Indirect, See footnote)
Footnotes (1)
  1. The reported securities are owned directly by NEXTBio Master Fund LP and may be deemed to be indirectly beneficially owned by (i) NEXTBio Capital LLC, the general partner of NEXTBio Master Fund LP, (ii) NEXTBio Capital Management LP, the investment manager to NEXTBio Master Fund LP, and (iii) Hongbo Lu, a managing member of NEXTBio Capital LLC. The Reporting Person disclaims beneficial ownership of the reported securities except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose. The reported securities are owned directly by NEXTBio Master Fund LP or NextBio Evergreen LLC and may be deemed to be indirectly beneficially owned by (i) NEXTBio Capital LLC, the general partner of NEXTBio Master Fund LP (with respect to such securities directly owned by NEXTBio Master Fund LP), (ii) NEXTBio Capital Evergreen GP LLC, the managing member of NEXTBio Evergreen LLC (with respect to such securities directly owned by NextBio Evergreen LLC), (iii) NEXTBio Capital Management LP, the investment manager to NEXTBio Master Fund LP and NextBio Evergreen LLC, and (iv) Hongbo Lu, a managing member of NEXTBio Capital LLC and NEXTBio Capital Evergreen GP LLC. (Continued from footnote 2) The Reporting Person disclaims beneficial ownership of the reported securities except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.
Form 4 Insider Transactions: What Each Field Means →
SEC Form 4
FORM 4 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940
OMB APPROVAL
OMB Number: 3235-0287
Estimated average burden
hours per response: 0.5
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.
1. Name and Address of Reporting Person*
Lu Hongbo
(Last) (First) (Middle)
C/O ZENAS BIOPHARMA, INC.
852 WINTER ST., SUITE 250
(Street)
WALTHAM MA 02451
(City) (State) (Zip)
2. Issuer Name and Ticker or Trading Symbol
Zenas BioPharma, Inc. [ ZBIO ] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
X Director 10% Owner
Officer (give title below) Other (specify below)
3. Date of Earliest Transaction (Month/Day/Year)
09/13/2024
4. If Amendment, Date of Original Filed (Month/Day/Year)
 6. Individual or Joint/Group Filing (Check Applicable Line)
X Form filed by One Reporting Person
Form filed by More than One Reporting Person
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 09/13/2024 P 58,823 A $17 58,823 I(1) See footnote(1)
Common Stock 10/07/2025 P 263,160 A $19 321,983 I(2)(3) See footnote(2)(3)
Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 6. Date Exercisable and Expiration Date (Month/Day/Year) 7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Explanation of Responses:
1. The reported securities are owned directly by NEXTBio Master Fund LP and may be deemed to be indirectly beneficially owned by (i) NEXTBio Capital LLC, the general partner of NEXTBio Master Fund LP, (ii) NEXTBio Capital Management LP, the investment manager to NEXTBio Master Fund LP, and (iii) Hongbo Lu, a managing member of NEXTBio Capital LLC. The Reporting Person disclaims beneficial ownership of the reported securities except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.
2. The reported securities are owned directly by NEXTBio Master Fund LP or NextBio Evergreen LLC and may be deemed to be indirectly beneficially owned by (i) NEXTBio Capital LLC, the general partner of NEXTBio Master Fund LP (with respect to such securities directly owned by NEXTBio Master Fund LP), (ii) NEXTBio Capital Evergreen GP LLC, the managing member of NEXTBio Evergreen LLC (with respect to such securities directly owned by NextBio Evergreen LLC), (iii) NEXTBio Capital Management LP, the investment manager to NEXTBio Master Fund LP and NextBio Evergreen LLC, and (iv) Hongbo Lu, a managing member of NEXTBio Capital LLC and NEXTBio Capital Evergreen GP LLC.
3. (Continued from footnote 2) The Reporting Person disclaims beneficial ownership of the reported securities except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.
Hongbo Lu, By: Hongbo Lu 10/09/2025
** Signature of Reporting Person Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

Source: View Original Filing on SEC EDGAR

FAQ

What did Hongbo Lu report on the Form 4 for ZBIO?

The Form 4 reports two non-derivative purchases totaling 321,983 shares, acquired on 09/13/2024 and 10/07/2025 at $17 and $19 per share respectively.

Are the shares owned personally by Hongbo Lu?

No. The filing states the shares are owned directly by NEXTBio Master Fund LP and NextBio Evergreen LLC and may be deemed indirectly owned by NextBio Capital entities and Hongbo Lu; the reporting person disclaims direct beneficial ownership except for pecuniary interest.

What is Hongbo Lu's relationship to Zenas BioPharma (ZBIO)?

The Form 4 indicates Hongbo Lu is a Director of Zenas BioPharma and a managing member of NextBio Capital entities that hold the reported shares.

How much were the reported purchases and at what prices?

The first purchase was 58,823 shares at $17; the second was 263,160 shares at $19, totaling 321,983 shares.

Does this Form 4 show any derivative transactions or sales?

No. The filing lists only non-derivative acquisitions; Table II for derivative securities contains no reported transactions.