SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* Mostafa Adam S. (Last) (First) (Middle) C/O X4 PHARMACEUTICALS, INC. 955 MASSACHUSETTS AVENUE, 4TH FLOOR (Street) CAMBRIDGE MA 02139 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol X4 Pharmaceuticals, Inc [ XFOR ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director 10% Owner X Officer (give title below) Other (specify below) Chief Financial Officer
	3. Date of Earliest Transaction (Month/Day/Year) 08/14/2020
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) X Form filed by One Reporting Person 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. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction 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 Stock	08/14/2020		A		16,250(1)	A	$0	24,173(2)	D
Common Stock	08/17/2020		A		16,250(3)	A	$0	40,423(4)	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction 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 (Month/Day/Year)		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: 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. Represents restricted stock units issued to the Reporting Person. Each restricted stock unit represents a contingent right to receive one share of common stock of the Issuer and has no expiration date. One third of the shares underlying the restricted stock unit award vested on August 14, 2020. One third of the shares will vest on August 14, 2021, and one third of the shares will vest on August 14, 2022, subject to the Reporting Person providing continuous service to the Issuer on such dates. Shares in respect of the vested portion of the award must be delivered no later than March 15 of the calendar year following the year in which vesting occurs.

2. Of the shares of common stock reported, 18,756 Shares represent unvested restricted stock units.

3. Represents restricted stock units issued to the Reporting Person. Each restricted stock unit represents a contingent right to receive one share of common stock of the Issuer and has no expiration date. One third of the shares underlying the restricted stock unit award vested on August 17, 2020. One third of the shares will vest on August 17, 2021, and one third of the shares will vest on August 17, 2022, subject to the Reporting Person providing continuous service to the Issuer on such dates. Shares in respect of the vested portion of the award must be delivered no later than March 15 of the calendar year following the year in which vesting occurs.

4. Of the shares of common stock reported, 29,589 shares represent unvested restricted stock units.

Remarks:

	/s/ Derek M. Meisner, attorney-in-fact	08/18/2020
	** Signature of Reporting Person	Date
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).
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