# EDGAR Filing Document

**Accession Number:** 0002123613
**File Stem:** 0001193125-26-288406
**Filing Date:** 2026-6
**Character Count:** 29239
**Document Hash:** 431ed7ee3eedcc45e7dc8085a3b52dc1
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-26-288406.hdr.sgml**: 20260629

**ACCESSION NUMBER**: 0001193125-26-288406

**CONFORMED SUBMISSION TYPE**: SCHEDULE 13D

**PUBLIC DOCUMENT COUNT**: 2

**FILED AS OF DATE**: 20260629

**DATE AS OF CHANGE**: 20260629

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Kardigan, Inc.
- **CENTRAL INDEX KEY:** 0002123613
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 932994203
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13D
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-95771
- **FILM NUMBER:** 261135698

**BUSINESS ADDRESS:**
- **STREET 1:** C/O KARDIGAN, INC.
- **STREET 2:** 131 OYSTER POINT BLVD., SECOND FLOOR
- **CITY:** SOUTH SAN FRANCISCO
- **STATE:** CA
- **ZIP:** 94080
- **BUSINESS PHONE:** (415) 573-3220

**MAIL ADDRESS:**
- **STREET 1:** C/O KARDIGAN, INC.
- **STREET 2:** 131 OYSTER POINT BLVD., SECOND FLOOR
- **CITY:** SOUTH SAN FRANCISCO
- **STATE:** CA
- **ZIP:** 94080
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** ARCH Venture Fund XIII, L.P.
- **CENTRAL INDEX KEY:** 0002006772

**ORGANIZATION NAME:**
- **EIN:** 000000000
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

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

**BUSINESS ADDRESS:**
- **STREET 1:** 8755 W. HIGGINS ROAD, SUITE 1025
- **CITY:** CHICAGO
- **STATE:** IL
- **ZIP:** 60631
- **BUSINESS PHONE:** 773-380-6600

**MAIL ADDRESS:**
- **STREET 1:** 8755 W. HIGGINS ROAD, SUITE 1025
- **CITY:** CHICAGO
- **STATE:** IL
- **ZIP:** 60631

## Exhibit 1.1

<u>Exhibit 1</u>

<u>AGREEMENT</u>

Pursuant to Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, the undersigned hereby agree that only one statement containing the information required by Schedule 13D need be filed with respect to the ownership by each of the undersigned of shares of stock of Kardigan, Inc.

This Agreement may be executed in any number of counterparts, each of which shall be deemed an original.

Dated: June 29, 2026

ARCH VENTURE FUND XIII, L.P.

By: ARCH Venture Partners XIII, L.P.

its General Partner

By: ARCH Venture Partners XIII, LLC

its General Partner

By: <u>\*</u> 

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Keith Crandell

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Managing Director

ARCH VENTURE PARTNERS XIII, L.P.

By: ARCH Venture Partners XIII, LLC

its General Partner

By: <u>\*</u> 

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Keith Crandell

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Managing Director

ARCH VENTURE PARTNERS XIII, LLC

By: <u>\*</u> 

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Keith Crandell

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Managing Director

 <u>\*</u> 

Keith Crandell

 <u>\*</u> 

Robert Nelsen

 <u>\*</u> 

Kristina Burow

 <u>\*</u> 

Steven Gillis

 <u>\*</u> 

Paul Berns

\* By: <u>/s/ Mark McDonnell</u> 

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Mark McDonnell as

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Attorney-in-Fact

\* This Agreement of Joint Filing was executed by Mark McDonnell pursuant to a Power of Attorney filed as Exhibit 24.1 to the Form 3 relating to the beneficial ownership of shares of Metsera, Inc. by the Reporting Persons filed with the Securities Exchange Commission on January 30, 2025 and incorporated herein in its entirety by reference.

------

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

## SCHEDULE 13D

### Under the Securities Exchange Act of 1934

**Kardigan, Inc.**

*(Name of Issuer)*

**Common Stock, $0.00001 par value per share**

*(Title of Class of Securities)*

**—**

*(CUSIP Number)*

**Mark McDonnell**<br>ARCH Venture Management, LLC<br>8755 W. Higgins Road, Suite 1025<br>Chicago IL 60631<br>(773) 380 6600

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

**06/22/2026**

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

| **CUSIP No.** | **—** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**ARCH Venture Fund XIII, L.P.** | Name of reporting person<br>**ARCH Venture Fund XIII, L.P.** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (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>**15042035.00** |
| 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>**15042035.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**15042035.00** | Aggregate amount beneficially owned by each reporting person<br>**15042035.00** | |
| 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>**16.2%** | Percent of class represented by amount in Row (11)<br>**16.2%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**PN** | Type of Reporting Person (See Instructions)<br>**PN** | |

---

| **CUSIP No.** | **—** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**ARCH Venture Partners XIII, L.P.** | Name of reporting person<br>**ARCH Venture Partners XIII, L.P.** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (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>**15042035.00** |
| 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>**15042035.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**15042035.00** | Aggregate amount beneficially owned by each reporting person<br>**15042035.00** | |
| 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>**16.2%** | Percent of class represented by amount in Row (11)<br>**16.2%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**PN** | Type of Reporting Person (See Instructions)<br>**PN** | |

---

| **CUSIP No.** | **—** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**ARCH Venture Partners XIII, LLC** | Name of reporting person<br>**ARCH Venture Partners XIII, LLC** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (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>**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>**15042035.00** |
| 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>**15042035.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**15042035.00** | Aggregate amount beneficially owned by each reporting person<br>**15042035.00** | |
| 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>**16.2%** | Percent of class represented by amount in Row (11)<br>**16.2%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**OO** | Type of Reporting Person (See Instructions)<br>**OO** | |

---

| **CUSIP No.** | **—** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Robert Nelsen** | Name of reporting person<br>**Robert Nelsen** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (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>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**15042035.00** |
| 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>**15042035.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**15042035.00** | Aggregate amount beneficially owned by each reporting person<br>**15042035.00** | |
| 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>**16.2%** | Percent of class represented by amount in Row (11)<br>**16.2%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**IN** | Type of Reporting Person (See Instructions)<br>**IN** | |

---

| **CUSIP No.** | **—** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Keith Crandell** | Name of reporting person<br>**Keith Crandell** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (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>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**15042035.00** |
| 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>**15042035.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**15042035.00** | Aggregate amount beneficially owned by each reporting person<br>**15042035.00** | |
| 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>**16.2%** | Percent of class represented by amount in Row (11)<br>**16.2%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**IN** | Type of Reporting Person (See Instructions)<br>**IN** | |

---

| **CUSIP No.** | **—** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Kristina Burow** | Name of reporting person<br>**Kristina Burow** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (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>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**15042035.00** |
| 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>**15042035.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**15042035.00** | Aggregate amount beneficially owned by each reporting person<br>**15042035.00** | |
| 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>**16.2%** | Percent of class represented by amount in Row (11)<br>**16.2%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**IN** | Type of Reporting Person (See Instructions)<br>**IN** | |

---

| **CUSIP No.** | **—** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Steven Gillis** | Name of reporting person<br>**Steven Gillis** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (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>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**15042035.00** |
| 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>**15042035.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**15042035.00** | Aggregate amount beneficially owned by each reporting person<br>**15042035.00** | |
| 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>**16.2%** | Percent of class represented by amount in Row (11)<br>**16.2%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**IN** | Type of Reporting Person (See Instructions)<br>**IN** | |

---

| **CUSIP No.** | **—** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Paul Berns** | Name of reporting person<br>**Paul Berns** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (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>**53483.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**15042035.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**53483.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**15042035.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**15095518.00** | Aggregate amount beneficially owned by each reporting person<br>**15095518.00** | |
| 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>**16.2%** | Percent of class represented by amount in Row (11)<br>**16.2%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**IN** | Type of Reporting Person (See Instructions)<br>**IN** | |

---

**Item 1. Security and Issuer**

**(a) Title of Class of Securities:**
Common Stock, $0.00001 par value per share

**(b) Name of Issuer:**
Kardigan, Inc.

**(c) Address of Issuer's Principal Executive Offices:**
506 Carnegie Center Drive, Suite 201, Princeton, NJ, 08540

**Item 4. Purpose of Transaction**

AVF XIII and the other Reporting Persons acquired the Common Stock for investment purposes. Depending on market conditions, the continuing evaluation of the business and prospects of the Issuer and other factors, AVF XIII and other Reporting Persons may dispose of or acquire additional shares of Common Stock of the Issuer.  Except as set forth above, none of the Reporting Persons has any present plans which relate to or would result in the matters set forth in subparagraphs (a) - (j) of Item 4 of Schedule 13D.

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

**(a)**
AVF XIII is the record owner of 15,042,035 shares of Common Stock and Warrants exercisable for 876,040 shares of Common Stock ("AVF XIII Record Shares"). AVP XIII LP, as the sole general partner of AVF XIII LP, may be deemed to beneficially own the AVF XIII Record Shares. AVP XIII LLC, as the sole general partner of AVP XIII LP, may be deemed to beneficially own the AVF XIII Record Shares. The Warrants may not be exercised until the first date on which the Issuer achieves a market valuation of $5.0 billion. As a result, none of the Warrants are currently exercisable.

By virtue of their relationship as affiliated entities who have overlapping general partners and investment committee members, each of the AVP XIII Investment Committee Members and direct and indirect general partners of AVF XIII may be deemed to share the power to direct the AVF XIII Record Shares.

Berns is the holder of options to purchase 113,513 shares of common stock, of which 53,483 are exercisable now and within the next 60 days, and 20,706 restricted stock units, of which 0 are exercisable now and within the next 60 days.

Each Reporting Person disclaims beneficial ownership of the AVF XIII Record Shares except for the shares, if any, held of record by such Reporting Person.

The percentage of outstanding Common Stock of the Issuer 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 the 93,089,121 shares outstanding following the IPO, as reported by the Issuer in its Prospectus filed pursuant to Rule 424(b)(4) with the Securities and Exchange Commission on June 17, 2026, giving effect to the exercise of the underwriters' allotment, and includes vested options in the shares reported for Berns.

**(b)**
Regarding the number of shares as to which such person has:

(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.

**(c)**
Except as set forth in this Schedule 13D, none of the Reporting Persons has effected any transaction in the Common Stock during the last 60 days.

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

Investor Rights Agreement

AVF XIII is party to that certain Amended and Restated Investors' Rights Agreement, dated September 4, 2025 (the "Investor Rights Agreement").  Pursuant to the Investor Rights Agreement, the Issuer has granted to AVF XIII demand, piggyback and shelf registration rights with respect to shares of Common Stock held by AVF XIII.  Such registration rights will terminate upon the earlier of (i) the occurrence of a deemed liquidation event, as defined in the Issuer's amended and restated certificate of incorporation, as currently in effect, (ii) such date after the completion of the IPO when AVF XIII (A) together with its affiliates (as determined under Rule 144 of the Securities Act) holds less than 1% of the Issuer's outstanding capital stock and (B) may immediately sell all registrable securities held by it pursuant to Rule 144 of the Securities Act without any volume limitations, or another similar exemption, during any three month period without registration, and (iii) the third anniversary of the IPO.

Effective as of the closing of the IPO, the covenants relating to delivery of financial statements and inspection rights set forth in Section 3 and the rights of first offer were terminated.

The foregoing description of the Investor Rights Agreement does not purport to be complete and is qualified in its entirety by reference to the full text of such agreement, which is filed as Exhibit 2 to this Schedule 13D and is incorporated herein by reference.

Lock-Up Agreement

AVF XIII has entered into a lock-up agreement with the underwriters of the IPO (the "Lock-Up Agreement") pursuant to which AVF XIII has agreed, subject to certain exceptions, not to offer, pledge, announce the intention to sell, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase or otherwise dispose of, directly or indirectly, or enter into any swap or other agreement that transfers, in whole or in part, any of the economic consequences of ownership of the Common Stock for a period of 180 days after June 17, 2026, except with the prior written consent of J.P. Morgan Securities LLC, Jefferies LLC, Leerink Partners LLC and TD Securities (USA) LLC, subject to certain exceptions.

The foregoing description of the Lock-Up Agreement does not purport to be complete and is qualified in its entirety by reference to the full text of such agreement, the form of which is filed as Exhibit 3 to this Schedule 13D and is incorporated herein by reference.

Warrants

In connection with the issuance of the Series B Preferred Stock, AVF XIII was issued by the Issuer a Warrant exercisable for 876,040 shares of Common Stock at an exercise price of $13.4135 per share (after giving effect to the Stock Split). The Warrant is exercisable, in whole or in part, only upon the first date on which the Issuer achieves a market valuation of $5.0 billion, and expires on September 4, 2035.

The foregoing description of the Warrant does not purport to be complete and is qualified in its entirety by reference to the full text of such Warrant, which is filed as Exhibit 4 to this Schedule 13D and is incorporated herein by reference.

### 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:** ARCH Venture Fund XIII, L.P.

**Signature:** ARCH Venture Partners XIII, L.P.

**Name/Title:** its General Partner

**Date:** 06/29/2026

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:** ARCH Venture Partners XIII, L.P.

**Signature:** ARCH Venture Partners XIII, LLC

**Name/Title:** its General Partner

**Date:** 06/29/2026

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:** ARCH Venture Partners XIII, LLC

**Signature:** /s/ Mark McDonnell*

**Name/Title:** Mark McDonnell, as Attorney-in-Fact for Keith Crandell, Managing Director

**Date:** 06/29/2026

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:** Robert Nelsen

**Signature:** /s/ Mark McDonnell*

**Name/Title:** Mark McDonnell, as Attorney-in-Fact for Robert Nelsen

**Date:** 06/29/2026

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:** Keith Crandell

**Signature:** /s/ Mark McDonnell*

**Name/Title:** Mark McDonnell, as Attorney-in-Fact for Keith Crandell

**Date:** 06/29/2026

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:** Kristina Burow

**Signature:** /s/ Mark McDonnell*

**Name/Title:** Mark McDonnell, as Attorney-in-Fact for Kristina Burow

**Date:** 06/29/2026

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:** Steven Gillis

**Signature:** /s/ Mark McDonnell*

**Name/Title:** Mark McDonnell, as Attorney-in-Fact for Steven Gillis

**Date:** 06/29/2026

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:** Paul Berns

**Signature:** /s/ Mark McDonnell*

**Name/Title:** Mark McDonnell, as Attorney-in-Fact for Paul Berns

**Date:** 06/29/2026