[SCHEDULE 13G/A] X4 Pharmaceuticals, Inc. SEC Filing

Rhea-AI Filing Summary

OrbiMed Advisors LLC filed an amended Schedule 13G reporting beneficial ownership of 134,947 warrants of X4 Pharmaceuticals, Inc., representing 1.7% of the company’s common stock on a fully diluted basis. The filing states the warrants confer shared voting and dispositive power over 134,947 warrants and that OrbiMed holds these warrants on behalf of other persons. OrbiMed’s investment and voting authority is exercised through a management committee of three named members, each disclaiming beneficial ownership. The filing affirms the holdings were not acquired to influence control of the issuer.

Insights

Securities Analyst

TL;DR: Routine Schedule 13G/A disclosing a modest 1.7% warrant position; no control intent stated.

The filing documents a passive reporting position by OrbiMed Advisors LLC: 134,947 warrants equating to 1.7% of X4 Pharmaceuticals on an aggregate basis. The report indicates shared voting and dispositive power but affirms the position was not acquired to change control. Given the sub-5% stake and the adviser classification, this is a disclosure of interest rather than an activist or control-oriented move. Material impact on capital structure or governance is unlikely based on the disclosed percentages.

Corporate Governance Expert

TL;DR: Disclosure is consistent with regulatory transparency; committee members disclaiming beneficial ownership is standard.

The statement clarifies that investment and voting authority is exercised via a management committee (three named individuals) who disclaim beneficial ownership, a common structure for investment advisers reporting aggregated client positions. The filing’s certification that the holdings were not acquired to influence control reduces governance concern. Because the position is below 5% and recorded as warrants, it does not indicate immediate dilution or control shifts that would materially affect shareholder voting dynamics.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 5)

X4 Pharmaceuticals, Inc

(Name of Issuer)

Common Stock, par value $0.001 per share

(Title of Class of Securities)

98420X103

(CUSIP Number)

06/30/2025

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

SCHEDULE 13G

CUSIP No. 98420X103

1

Names of Reporting Persons

ORBIMED ADVISORS LLC

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 134,947.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 134,947.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

134,947.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

1.7 %

12

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13G

Item 1.
(a)	Name of issuer: X4 Pharmaceuticals, Inc
(b)	Address of issuer's principal executive offices: 61 North Beacon Street, 4th Floor Boston, Massachusetts 02134
Item 2.
(a)	Name of person filing: OrbiMed Advisors LLC
(b)	Address or principal business office or, if none, residence: 601 Lexington Avenue, 54th Floor New York, NY 10022
(c)	Citizenship: Delaware.
(d)	Title of class of securities: Common Stock, par value $0.001 per share
(e)	CUSIP No.: 98420X103
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: OrbiMed Advisors LLC: 134,947 warrants to purchase shares of Common Stock
(b)	Percent of class: 1.7%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 0
	(ii) Shared power to vote or to direct the vote: 134,947 warrants
	(iii) Sole power to dispose or to direct the disposition of: 0
	(iv) Shared power to dispose or to direct the disposition of: 134,947 warrants
Item 5.	Ownership of 5 Percent or Less of a Class.
	Ownership of 5 percent or less of a class
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required. The Reporting Person hold 134,947 warrants, which upon conversion equals to 1.7% of the shares of Common Stock in the aggregate on behalf of other persons who have the right to receive or the power to direct the receipt of dividends from, or proceeds from the sale of, such securities. OrbiMed Advisors LLC exercises investment and voting power over the shares of Common Stock through a management committee comprised of Carl L. Gordon, Sven H. Borho, and W. Carter Neild, each of whom disclaims beneficial ownership of the shares of Common Stock reported herein.
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	Not Applicable
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.

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.

ORBIMED ADVISORS LLC

Signature:	/s/ Carl L. Gordon
Name/Title:	Carl L. Gordon, Member
Date:	08/14/2025

FAQ

What stake does OrbiMed Advisors LLC report in X4 Pharmaceuticals (XFOR)?

OrbiMed Advisors LLC reports beneficial ownership of 134,947 warrants, representing 1.7% of the common stock on an aggregate basis.

Does OrbiMed have sole voting or dispositive power over the reported securities?

No. The filing states OrbiMed has 0 sole voting and 0 sole dispositive power and shared voting and shared dispositive power over 134,947 warrants.

Are these holdings reported as intended to influence control of X4 Pharmaceuticals?

The filing includes a certification that the securities were not acquired and are not held for the purpose of changing or influencing control of the issuer.

Who exercises investment and voting authority for these holdings?

Investment and voting authority is exercised through a management committee comprised of Carl L. Gordon, Sven H. Borho, and W. Carter Neild, each of whom disclaims beneficial ownership.

What class of securities is disclosed in this Schedule 13G/A?

The filing discloses warrants to purchase Common Stock of X4 Pharmaceuticals, par value $0.001 per share, CUSIP 98420X103.