Statement of Changes in Beneficial Ownership (4)

FORM 4

[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

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

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

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3235-0287

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Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

1. Name and Address of Reporting Person * RTW INVESTMENTS, LP	2. Issuer Name and Ticker or Trading Symbol Milestone Pharmaceuticals Inc. [ MIST ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director                    __X__ 10% Owner _____ Officer (give title below)    _____ Other (specify below)
(Last)          (First)          (Middle) 412 WEST 15TH STREET, FLOOR 9,	3. Date of Earliest Transaction (MM/DD/YYYY) 3/18/2020
(Street) NEW YORK, NY 10011 (City)        (State)        (Zip)	4. If Amendment, Date Original Filed (MM/DD/YYYY)	6. Individual or Joint/Group Filing (Check Applicable Line) ___ Form filed by One Reporting Person _ X _ 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. Trans. Date	2A. Deemed Execution Date, if any	3. Trans. 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 Shares	3/18/2020		P		2705	A	$10.3618	4309232	I	By RTW (1)
Common Shares	3/19/2020		P		5870	A	$10.8695	4315102	I	By RTW (1)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	4. Trans. 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		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 of Derivative Security: 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 securities reported herein may be deemed beneficially owned by each of: (i) RTW Investments, LP ("RTW"), which is deemed the beneficial owner of shares held by RTW Master Fund, Ltd., RTW Venture Fund Limited and RTW Innovation Master Fund, Ltd. (the "Funds"), which are investment funds managed by RTW, and (ii) Roderick Wong, M.D who serves as the Managing Partner and Chief Investment Officer of RTW. Dr. Wong exercises voting and dispositive control over the securities held by RTW and is therefore deemed to be a beneficial owner of securities owned or controlled by RTW. Each of RTW and Dr. Wong disclaim beneficial ownership of the reported securities held by the Funds, except to the extent of its or his pecuniary interest therein.

Reporting Owners
Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
RTW INVESTMENTS, LP 412 WEST 15TH STREET, FLOOR 9 NEW YORK, NY 10011		X
WONG RODERICK C/O RTW INVESTMENTS, LP 412 WEST 15TH STREET, FLOOR 9 NEW YORK, NY 10011		X

Signatures
RTW Investments, LP By: /s/ Roderick Wong, Managing Partner		3/19/2020
**Signature of Reporting Person		Date
Roderick Wong By: /s/ Roderick Wong		3/19/2020
**Signature of Reporting Person		Date