# EDGAR Filing Document

**Accession Number:** 0001408443
**File Stem:** 0000902664-23-002379
**Filing Date:** 2023-3
**Character Count:** 8017
**Document Hash:** 5e32fe366df578d4cacf9b3310b39a93
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000902664-23-002379.hdr.sgml**: 20230324

**ACCESSION NUMBER**: 0000902664-23-002379

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20230322

**FILED AS OF DATE**: 20230324

**DATE AS OF CHANGE**: 20230324

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** RTW INVESTMENTS, LP
- **CENTRAL INDEX KEY:** 0001493215
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-38899
- **FILM NUMBER:** 23760246

**BUSINESS ADDRESS:**
- **STREET 1:** 40 10TH AVENUE
- **STREET 2:** 7TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10014
- **BUSINESS PHONE:** 646-597-6980

**MAIL ADDRESS:**
- **STREET 1:** 40 10TH AVENUE
- **STREET 2:** 7TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10014

**FORMER NAME:**
- **FORMER CONFORMED NAME:** RTW INVESTMENTS, LLC
- **DATE OF NAME CHANGE:** 20100602
**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** WONG RODERICK
- **CENTRAL INDEX KEY:** 0001493280

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-38899
- **FILM NUMBER:** 23760245

**MAIL ADDRESS:**
- **STREET 1:** C/O RTW INVESTMENTS, LP
- **STREET 2:** 40 10TH AVENUE, 7TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10014
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Milestone Pharmaceuticals Inc.
- **CENTRAL INDEX KEY:** 0001408443
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **IRS NUMBER:** 000000000
- **STATE OF INCORPORATION:** A8
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 1111 BOUL. DR.-FREDERIK-PHILIPS, STE 420
- **CITY:** MONTREAL
- **STATE:** A8
- **ZIP:** H4M 2X6
- **BUSINESS PHONE:** (514) 336-0444

**MAIL ADDRESS:**
- **STREET 1:** 1111 BOUL. DR.-FREDERIK-PHILIPS, STE 420
- **CITY:** MONTREAL
- **STATE:** A8
- **ZIP:** H4M 2X6

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

## FORM 4

### STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

[x] 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>RTW INVESTMENTS, LP<br><sub>(Last) (First) (Middle)</sub><br>40 10TH AVENUE<br>7TH FLOOR<br><sub>(Street)</sub><br>NEW YORK, NY 10014<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2023-03-22 | **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>Milestone Pharmaceuticals Inc. [ MIST ] | **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>WONG RODERICK<br><sub>(Last) (First) (Middle)</sub><br>C/O RTW INVESTMENTS, LP<br>40 10TH AVENUE, 7TH FLOOR<br><sub>(Street)</sub><br>NEW YORK, NY 10014<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2023-03-22 | **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>Milestone Pharmaceuticals Inc. [ MIST ] | **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 Shares, no par value ("Common Shares") | 2023-03-22 |  | J<sup>(1)</sup> |  | 1059000 | D | <sup>(1)</sup> | 3256102 | I | See footnote<sup>(2)</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) The RTW Funds (as defined below) exchanged 1,059,000 Common Shares for 1,059,000 pre-funded warrants pursuant to an Exchange Agreement, dated as of March 22, 2023, by and among the Issuer and the RTW Funds. Each pre-funded warrant represents the right to acquire one Common Share for an exercise price of $0.001 per share. The pre-funded warrants are subject to a 9.99% beneficial ownership limitation and do not have an expiration date.

(2) This Form 4 is being filed by each of (i) RTW Investments, LP (the "Adviser") with respect to Common Shares held by certain investment funds managed by the Adviser (the "RTW Funds"), and (ii) Roderick Wong, M.D., who serves as the Managing Partner and Chief Investment Officer of the Adviser.

**Signature:** RTW Investments, LP, By: /s/ Roderick Wong, Managing Partner  
**Date:** 2023-03-24

**Signature:** Roderick Wong, M.D., By: /s/ Roderick Wong  
**Date:** 2023-03-24

### 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.**