# EDGAR Filing Document

**Accession Number:** 0001228865
**File Stem:** 0001104659-25-098408
**Filing Date:** 2025-10
**Character Count:** 19841
**Document Hash:** a055592e9cfd9b024e135afec2c079f8
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-25-098408.hdr.sgml**: 20251009

**ACCESSION NUMBER**: 0001104659-25-098408

**CONFORMED SUBMISSION TYPE**: SCHEDULE 13D/A

**PUBLIC DOCUMENT COUNT**: 2

**FILED AS OF DATE**: 20251009

**DATE AS OF CHANGE**: 20251009

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Zenas BioPharma, Inc.
- **CENTRAL INDEX KEY:** 0001953926
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 000000000
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13D/A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-94625
- **FILM NUMBER:** 251385847

**BUSINESS ADDRESS:**
- **STREET 1:** 852 WINTER STREET, SUITE 250
- **CITY:** WALTHAM
- **STATE:** MA
- **ZIP:** 02451
- **BUSINESS PHONE:** 857-271-2954

**MAIL ADDRESS:**
- **STREET 1:** 852 WINTER STREET, SUITE 250
- **CITY:** WALTHAM
- **STATE:** MA
- **ZIP:** 02451

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Zenas BioPharma (Cayman) Ltd
- **DATE OF NAME CHANGE:** 20221108
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** MOULDER LEON O JR
- **CENTRAL INDEX KEY:** 0001228865

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13D/A

**MAIL ADDRESS:**
- **STREET 1:** C/O TESARO, INC.
- **STREET 2:** 1000 WINTER STREET, SUITE 3300
- **CITY:** WALTHAM
- **STATE:** MA
- **ZIP:** 02451

## Ex-1

**Exhibit 1**

**JOINT FILING AGREEMENT**

The undersigned hereby agree that the foregoing statement on Schedule 13D is filed on behalf of each of the undersigned, and any amendments thereto executed by the undersigned shall be filed on behalf of each of the undersigned without the necessity of filing any additional joint filing agreement. The undersigned acknowledge that each is responsible for the timely filing of such statement on Schedule 13D and any amendments thereto, and for the completeness and accuracy of the information concerning him or it contained therein, but shall not be responsible for the completeness or accuracy of the information concerning the others of the undersigned, except to the extent that he or it knows or has reason to believe that such information is inaccurate or incomplete. This Joint Filing Agreement may be executed in any number of counterparts, all of which taken together shall constitute one and the same instrument.

Dated: October 9, 2025

---

| | |
|:---|:---|
| **TELLUS BIOVENTURES, LLC** | **TELLUS BIOVENTURES, LLC** |
| By: | /s/ Leon O. Moulder, Jr. |
|  | Leon O. Moulder, Jr., Managing Member |

---

---

| | |
|:---|:---|
| **LEON O. MOULDER, JR. REVOCABLE TRUST U/A DTD 9/9/2008** | **LEON O. MOULDER, JR. REVOCABLE TRUST U/A DTD 9/9/2008** |
| By: | /s/ Leon O. Moulder, Jr. |
|  | Leon O. Moulder, Jr., Trustee |

---

---

| |
|:---|
| /s/ Leon O. Moulder, Jr. |
| Leon O. Moulder, Jr. |

---

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## SCHEDULE 13D

### Under the Securities Exchange Act of 1934

**(Amendment No. 1)**

**Zenas BioPharma, Inc.**

*(Name of Issuer)*

**Common Stock, $0.0001 par value per share**

*(Title of Class of Securities)*

**98937L105**

*(CUSIP Number)*

**Leon O. Moulder, Jr.**<br>c/o Zenas BioPharma, Inc.<br>852 Winter Street, Suite 250<br>Waltham MA 02451<br>857-271-2954

*(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)*

**10/07/2025**

*(Date of Event Which Requires Filing of this Statement)*

| **CUSIP No.** | **98937L105** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Leon O. Moulder, Jr.** | Name of reporting person<br>**Leon O. Moulder, Jr.** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**AF** | Source of funds (See Instructions)<br>**AF** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**X1** | Citizenship or place of organization<br>**X1** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**885695.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**1708967.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**885695.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**1708967.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**2594662.00** | Aggregate amount beneficially owned by each reporting person<br>**2594662.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**4.8%** | Percent of class represented by amount in Row (11)<br>**4.8%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**IN** | Type of Reporting Person (See Instructions)<br>**IN** | |

---

**Comment for Reporting Person:** (1) Rows 7 & 9: Consists of (i) 266,155 shares of common stock held directly by Mr. Moulder, and (ii) 619,540 shares of common stock underlying outstanding stock options exercisable within 60 days of the date of October 7, 2025.

(2) Rows 8 & 10: Consists of (i) 1,672,039 shares of common stock held by Tellus BioVentures, LLC ("Tellus") and (ii) 36,928 shares of common stock held by Leon O. Moulder, Jr. Revocable Trust U/A dtd 9/9/2008 (the "Trust"). Mr. Moulder is the Managing Member of Tellus and may be deemed to have sole voting and dispositive power over the shares held by Tellus, and Mr. Moulder is a trustee of the Trust and may be deemed to have sole voting and dispositive power of the shares held by the Trust.

(3) Row 11: Consists of (i) 266,155 shares of common stock held directly by Mr. Moulder, (ii) 619,540 shares of common stock underlying outstanding stock options exercisable within 60 days of October 7, 2025, (iii) 1,672,039 shares of common stock held by Tellus and (iv) 36,928 shares of common stock held by the Trust. Mr. Moulder is the Managing Member of Tellus and may be deemed to have sole voting and dispositive power over the shares held by Tellus, and Mr. Moulder is a trustee of the Trust and may be deemed to have sole voting and dispositive power of the shares held by the Trust.

(4) Row 13: Calculated based on 42,110,313 shares of Common Stock outstanding, as reported by the Issuer in its Quarterly Report on Form 10-Q for the three months ended June 30, 2025, as filed with the Securities and Exchange Commission (the "Commission") on August 12, 2025 (the "Q2 2025 Form 10-Q"), plus (i) 5,000,000 shares of common stock issued by the Issuer to InnoCare Pharma Inc. on October 7, 2025 (the "InnoCare Shares"), as reported by the Issuer in its Current Report on Form 8-K filed with the Commission on October 8, 2025, (ii) 6,311,030 shares of common stock issued by the Issuer to certain investors pursuant to that certain Securities Purchase Agreement, dated as of October 7, 2025 (the "PIPE Purchase Agreement" and such shares, the "PIPE Shares"), as reported by the issuer in its Registration Statement on Form S-3ASR filed with the Commission on October 8, 2025 (the "Shelf Registration Statement"), and (iii) the 619,540 shares of common stock issuable upon the exercise of the options held by Mr. Moulder that are exercisable within 60 days of October 7, 2025.

| **CUSIP No.** | **98937L105** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Tellus BioVentures, LLC** | Name of reporting person<br>**Tellus BioVentures, LLC** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**WC** | Source of funds (See Instructions)<br>**WC** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**1672039.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**1672039.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**1672039.00** | Aggregate amount beneficially owned by each reporting person<br>**1672039.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**3.1%** | Percent of class represented by amount in Row (11)<br>**3.1%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**OO** | Type of Reporting Person (See Instructions)<br>**OO** | |

---

**Comment for Reporting Person:** (1) Rows 8, 10 & 11: Consists of 1,672,039 shares of common stock held of record by Tellus. Mr. Moulder is the Managing Member of Tellus and may be deemed to have sole voting and dispositive power over the shares held by Tellus.

(2) Row 13: Calculated based on 42,110,313 shares of Common Stock outstanding, as reported by the Issuer in the Q2 2025 10-Q, plus (i) the InnoCare Shares and (ii) the PIPE Shares.

| **CUSIP No.** | **98937L105** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Leon O. Moulder, Jr. Revocable Trust U/A dtd 9/9/2008** | Name of reporting person<br>**Leon O. Moulder, Jr. Revocable Trust U/A dtd 9/9/2008** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**AF** | Source of funds (See Instructions)<br>**AF** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**FLORIDA** | Citizenship or place of organization<br>**FLORIDA** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**36928.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**36928.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**36928.00** | Aggregate amount beneficially owned by each reporting person<br>**36928.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**0.1%** | Percent of class represented by amount in Row (11)<br>**0.1%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**OO** | Type of Reporting Person (See Instructions)<br>**OO** | |

---

**Comment for Reporting Person:** (1) Rows 8, 10 & 11: Consists of 36,928 shares of common stock held of record by Leon O. Moulder, Jr. Revocable Trust U/A dtd 9/9/2008 (the "Trust"). Mr. Moulder is a Trustee of the Trust and may be deemed to have sole voting and dispositive power over the shares held by the Trust.

(2) Row 13: Calculated based on 42,110,313 shares of Common Stock outstanding, as reported by the Issuer in the Q2 2025 10-Q, plus (i) the InnoCare Shares and (ii) the PIPE Shares.

**Item 1. Security and Issuer**

**(a) Title of Class of Securities:**
Common Stock, $0.0001 par value per share

**(b) Name of Issuer:**
Zenas BioPharma, Inc.

**(c) Address of Issuer's Principal Executive Offices:**
852 Winter Street, Suite 250, Waltham, MA, 02451

This Amendment No. 1 (this "Amendment") amends and supplements the Schedule 13D initially filed by Mr. Moulder and Tellus on June 6, 2025 (the "Original Schedule 13D"). Only those items that are hereby reported are amended; all other items reported in the Original Schedule 13D remain unchanged. Information given in response to each item shall be deemed incorporated by reference in all other items, as applicable. Capitalized terms not defined in this Amendment have the meanings ascribed to them in the Original Schedule 13D. This Amendment is filed with respect to the Common Stock, par value $0.0001 per share ("Common Stock"), of Zenas BioPharma, Inc., a Delaware corporation (the "Issuer"). The address of the principal executive offices of the Issuer is 852 Winter Street, Suite 250, Waltham, MA 02451.

**Item 4. Purpose of Transaction**

The information set forth in Item 3 of this Statement is incorporated herein by reference.

Mr. Moulder serves as the Chairman of the Issuer's Board of Directors and as its Chief Executive Officer. In such capacity, Mr. Moulder has influence over the corporate activities of the Issuer, including activities that may relate to items described in subparagraphs (a) through (j) of Item 4 of Schedule 13D. Except as described herein, the Reporting Persons have no present plans or proposals that relate to or would result in any of the transactions described in subparagraphs (a) through (j) of Item 4 of Schedule 13D. However, the Reporting Persons reserve the right to formulate in the future plans or proposals which may relate to or result in the transactions described in subparagraphs (a) through (j) of this Item 4. In addition to the foregoing, the Reporting Persons may engage in discussions from time to time with other members of the Issuer's management and/or Board of Directors and/or with other stockholders of the Issuer and/or other third parties. Such discussions may include, without limitation, discussions with respect to the governance, board composition, management, operations, business, assets, capitalization, financial condition, strategic plans and future of the Issuer, as well as other matters related to the Issuer. These discussions may also include a review of options for enhancing stockholder value through, among other things, various strategic alternatives (including acquisitions and divestitures) or operational or management initiatives.

The Reporting Persons hold the securities of the Issuer for general investment purposes. The Reporting Persons may, from time to time, depending on prevailing market, economic and other conditions, acquire additional shares of Common Stock or other securities of the Issuer, dispose of any such securities, or engage in discussions with the Issuer concerning such acquisitions or dispositions or further investments in the Issuer. The Reporting Persons intend to review their investment in the Issuer on a continuing basis and, depending upon the price and availability of shares of Common Stock or other securities of the Issuer, subsequent developments affecting the Issuer, the Issuer's business and prospects, other investment and business opportunities available to the Reporting Persons, general stock market and economic conditions, tax considerations and other factors considered relevant, may decide at any time to increase or to decrease the size of their investment in the Issuer in the open market, in privately negotiated transactions, pursuant to 10b5-1 trading plans or otherwise.

Mr. Moulder, in his capacity as Chief Executive Officer of the Issuer, may be entitled to receive cash compensation and equity compensation, including stock option or other equity awards, including pursuant to the Issuer's 2024 Equity Incentive Plan (the "2024 Plan"). Mr. Moulder does not receive any additional compensation for his service on the Board of Directors of the Issuer. The terms and provisions of the 2024 Plan are described in the Issuer's definitive proxy statement relating to its 2025 annual meeting of stockholders, which was filed with the Commission on March 11, 2025 (the "2025 Proxy").

**Item 5. Interest in Securities of the Issuer**

**(a)**
See Items 7-11 of the cover pages of this Statement and Item 2 above.

**(b)**
See Items 7-11 of the cover pages of this Statement and Item 2 above.

**(c)**
Except as reported in this Statement, no Reporting Person has effected any transactions in the Issuer's securities within the past 60 days.

**Item 6. Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer.**

Item 6 of the Original Schedule 13D is hereby amended and supplement by adding the following to the end of Item 6:

In connection with the Private Placement, on October 7, 2025, the Issuer entered into a Registration Rights Agreement (the "PIPE Registration Rights Agreement") with the PIPE Investors, pursuant to which the Issuer will prepare and file, within 15 days of the PIPE Closing and subject to certain allowable delays, an initial registration statement (the "PIPE Registration Statement") with the Commission to register for resale the PIPE Shares. The Issuer granted the PIPE Investors customary indemnification rights in connection with the PIPE Registration Rights Agreement. The PIPE Investors have also granted the Issuer customary indemnification rights in connection with the PIPE Registration Rights Agreement.

The above summary of the PIPE Registration Rights Agreement is qualified by reference to such description and the full text of the PIPE Registration Rights Agreement, a form of which is filed as Exhibit 4 to this Amendment and is incorporated by reference herein.

### 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.

**Reporting Person:** Leon O. Moulder, Jr.

**Signature:** /s/ Leon O. Moulder, Jr.

**Name/Title:** Leon O. Moulder, Jr.

**Date:** 10/09/2025

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.

**Reporting Person:** Tellus BioVentures, LLC

**Signature:** /s / Leon O. Moulder, Jr.

**Name/Title:** Leon O. Moulder, Jr., Managing Member

**Date:** 10/09/2025

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.

**Reporting Person:** Leon O. Moulder, Jr. Revocable Trust U/A dtd 9/9/2008

**Signature:** /s / Leon O. Moulder, Jr.

**Name/Title:** Leon O. Moulder, Jr., Trustee

**Date:** 10/09/2025