# EDGAR Filing Document

**Accession Number:** 0001099776
**File Stem:** 0001999371-25-008631
**Filing Date:** 2025-7
**Character Count:** 11524
**Document Hash:** 05afeabb2fc8de3ecbbc2e7758b88299
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001999371-25-008631.hdr.sgml**: 20250701

**ACCESSION NUMBER**: 0001999371-25-008631

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20250627

**FILED AS OF DATE**: 20250701

**DATE AS OF CHANGE**: 20250701

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** COULTER JAMES G
- **CENTRAL INDEX KEY:** 0001099776

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-42504
- **FILM NUMBER:** 251097291

**MAIL ADDRESS:**
- **STREET 1:** 301 COMMERCE STREET
- **STREET 2:** SUITE 3300
- **CITY:** FORT WORTH
- **STATE:** TX
- **ZIP:** 76102
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** WINKELRIED JON
- **CENTRAL INDEX KEY:** 0001366946

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-42504
- **FILM NUMBER:** 251097290

**MAIL ADDRESS:**
- **STREET 1:** C/O GOLDMAN, SACHS & CO.
- **STREET 2:** 85 BROAD STREET
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10004

**FORMER NAME:**
- **FORMER CONFORMED NAME:** JON WINKELRIED
- **DATE OF NAME CHANGE:** 20060621
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** TPG GP A, LLC
- **CENTRAL INDEX KEY:** 0001903793

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

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-42504
- **FILM NUMBER:** 251097292

**BUSINESS ADDRESS:**
- **STREET 1:** 301 COMMERCE STREET
- **STREET 2:** SUITE 3300
- **CITY:** FORT WORTH
- **STATE:** TX
- **ZIP:** 76102
- **BUSINESS PHONE:** (817) 871-4000

**MAIL ADDRESS:**
- **STREET 1:** 301 COMMERCE STREET
- **STREET 2:** SUITE 3300
- **CITY:** FORT WORTH
- **STATE:** TX
- **ZIP:** 76102
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Sionna Therapeutics, Inc.
- **CENTRAL INDEX KEY:** 0002036042
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 000000000
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 21 HICKORY DRIVE, SUITE 500
- **CITY:** WALTHAM
- **STATE:** MA
- **ZIP:** 02451
- **BUSINESS PHONE:** 617-819-2020

**MAIL ADDRESS:**
- **STREET 1:** 21 HICKORY DRIVE, SUITE 500
- **CITY:** WALTHAM
- **STATE:** MA
- **ZIP:** 02451

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

## FORM 4

### STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

[ ] 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**<sup>*</sup><br>TPG GP A, LLC<br><sub>(Last) (First) (Middle)</sub><br>C/O TPG INC.<br>301 COMMERCE STREET, SUITE 3300<br><sub>(Street)</sub><br>FORT WORTH, TX 76102<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-06-27 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] Director [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Sionna Therapeutics, Inc. [ SION ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>COULTER JAMES G<br><sub>(Last) (First) (Middle)</sub><br>C/O TPG GLOBAL, LLC<br>301 COMMERCE STREET, SUITE 3300<br><sub>(Street)</sub><br>FORT WORTH, TX 76102<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-06-27 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] Director [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Sionna Therapeutics, Inc. [ SION ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>WINKELRIED JON<br><sub>(Last) (First) (Middle)</sub><br>C/O TPG GLOBAL, LLC<br>301 COMMERCE STREET, SUITE 3300<br><sub>(Street)</sub><br>FORT WORTH, TX 76102<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2025-06-27 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] Director [X] 10% Owner<br>[ ] Officer (give title below) [ ] Other (specify below)<br>_ _ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>Sionna Therapeutics, Inc. [ SION ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[ ] Form filed by One Reporting Person<br>[X] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | 3. Transaction Code (V) | 3. Transaction Code (V) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | Code | V | Amount | (A) or (D) | Price | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| Common Stock | 2025-06-27 |  | P |  | 60000 | A | $15.84 | 6744962 | I | See Explanation of Responses<sup>(1)(2)(3)(4)</sup> |

---

## Table II - Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | 4. Transaction Code (V) | 4. Transaction Code (V) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 6. Date Exercisable and Expiration Date | 6. Date Exercisable and Expiration Date | 7. Title and Amount of Underlying Securities | 7. Title and Amount of Underlying Securities | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | Code | V | (A) | (D) | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

---

### Footnotes:

(1) Each of James G. Coulter and Jon Winkelried own entities that control TPG GP A, LLC (together with Messrs. Coulter and Winkelried, the "Reporting Persons"), which is the managing member of each of (i) TPG Group Holdings (SBS) Advisors, LLC, which is the general partner of TPG Group Holdings (SBS), L.P., and (ii) Alabama Investments (Parallel) GP, LLC, which is the general partner of each of (a) Alabama Investments (Parallel), LP, (b) Alabama Investments (Parallel) Founder A, LP and (c) Alabama Investments (Parallel) Founder G, LP, which, collectively with TPG Group Holdings (SBS), L.P., Alabama Investments (Parallel), LP and Alabama Investments (Parallel) Founder A, LP, holds 100% of the shares of Class B common stock (which represents a majority of the combined voting power of the common stock) of TPG Inc.

(2) TPG Inc. is the sole member of TPG GPCo, LLC, which is the sole member of TPG Holdings II-A, LLC, which is the general partner of TPG Operating Group II, L.P., which is the sole member of TPG Holdings I-A, LLC, which is the general partner of TPG Operating Group I, L.P., which is the sole member of The Rise Fund GenPar Advisors, LLC, which is the general partner of The Rise Fund GenPar, L.P., which is the managing member of The Rise Fund SPV GP, LLC, which is the general partner of each of The Rise Fund Sling, L.P., which directly holds 5,536,598 shares of Common Stock ("Common Stock") of Sionna Therapeutics, Inc. (the "Issuer"), and The Rise Fund Sling II, L.P. (together with The Rise Fund Sling, L.P., the "TPG Funds"), which directly holds 1,208,364 shares of Common Stock.

(3) Because of the relationship between the Reporting Persons and the TPG Funds, the Reporting Persons may be deemed to beneficially own the securities reported herein to the extent of the greater of their respective direct or indirect pecuniary interests in the profits or capital accounts of the TPG Funds. Each of the TPG Funds and each Reporting Person disclaims beneficial ownership of the securities reported herein, except to the extent of such TPG Fund's or such Reporting Person's pecuniary interest therein, if any.

(4) Pursuant to Rule 16a-1(a)(4) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), this filing shall not be deemed an admission that the Reporting Persons are, for purposes of Section 16 of the Exchange Act or otherwise, the beneficial owners of any equity securities in excess of their respective pecuniary interests.

**Remarks:**
5. The Reporting Persons are jointly filing this Form 4 pursuant to Rule 16a-3(j) under the Exchange Act.
6. Gerald Neugebauer is signing on behalf of Messrs. Coulter and Winkelried pursuant to authorization and designation letters dated January 10, 2024, which were previously filed with the Securities and Exchange Commission.

**Signature:** /s/ Martin Davidson, Chief Accounting Officer, TPG GP A, LLC (5)  
**Date:** 2025-07-01

**Signature:** /s/ Gerald Neugebauer, on behalf of James G. Coulter (5) (6)  
**Date:** 2025-07-01

**Signature:** /s/ Gerald Neugebauer, on behalf of Jon Winkelried (5) (6)  
**Date:** 2025-07-01

### Remarks:

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.**