<SEC-DOCUMENT>0000947871-22-000219-index.html : 20220211
<SEC-HEADER>0000947871-22-000219.hdr.sgml : 20220211
<ACCEPTANCE-DATETIME>20220211170828
ACCESSION NUMBER:		0000947871-22-000219
CONFORMED SUBMISSION TYPE:	SC 13G/A
PUBLIC DOCUMENT COUNT:		2
FILED AS OF DATE:		20220211
DATE AS OF CHANGE:		20220211
GROUP MEMBERS:		ORBIMED CAPITAL GP IV LLC

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			X4 Pharmaceuticals, Inc
		CENTRAL INDEX KEY:			0001501697
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		IRS NUMBER:				273181608
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-90199
		FILM NUMBER:		22622566

	BUSINESS ADDRESS:	
		STREET 1:		61 NORTH BEACON STREET
		STREET 2:		4TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02134
		BUSINESS PHONE:		857-529-8300

	MAIL ADDRESS:	
		STREET 1:		61 NORTH BEACON STREET
		STREET 2:		4TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02134

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Arsanis, Inc.
		DATE OF NAME CHANGE:	20100920

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ORBIMED ADVISORS LLC
		CENTRAL INDEX KEY:			0001055951
		IRS NUMBER:				133976876
		STATE OF INCORPORATION:			DE

	FILING VALUES:
		FORM TYPE:		SC 13G/A

	BUSINESS ADDRESS:	
		STREET 1:		601 LEXINGTON AVENUE
		STREET 2:		54TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
		BUSINESS PHONE:		(212) 739-6400

	MAIL ADDRESS:	
		STREET 1:		601 LEXINGTON AVENUE
		STREET 2:		54TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G/A
<SEQUENCE>1
<FILENAME>ss792583_sc13ga.htm
<DESCRIPTION>AMENDMENT NO. 2
<TEXT>
Document 1 - file: ss792583_sc13ga.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.A
<SEQUENCE>2
<FILENAME>ss792583_ex99a.htm
<DESCRIPTION>JOINT FILING AGREEMENT
<TEXT>
Document 2 - file: ss792583_ex99a.htm

</DOCUMENT>
</SEC-DOCUMENT>