<SEC-DOCUMENT>0000899243-19-017423-index.html : 20190619
<SEC-HEADER>0000899243-19-017423.hdr.sgml : 20190619
<ACCEPTANCE-DATETIME>20190619161927
ACCESSION NUMBER:		0000899243-19-017423
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20190617
FILED AS OF DATE:		20190619
DATE AS OF CHANGE:		20190619

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Russo Rene
		CENTRAL INDEX KEY:			0001722066

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-38295
		FILM NUMBER:		19906250

	MAIL ADDRESS:	
		STREET 1:		C/O ARSANIS, INC.
		STREET 2:		890 WINTER STREET, SUITE 230
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02451

ISSUER:		

	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

	BUSINESS ADDRESS:	
		STREET 1:		955 MASSACHUSETTS AVENUE
		STREET 2:		4TH FLOOR
		CITY:			CAMBRIDGE
		STATE:			MA
		ZIP:			02139
		BUSINESS PHONE:		857-529-8300

	MAIL ADDRESS:	
		STREET 1:		955 MASSACHUSETTS AVENUE
		STREET 2:		4TH FLOOR
		CITY:			CAMBRIDGE
		STATE:			MA
		ZIP:			02139

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Arsanis, Inc.
		DATE OF NAME CHANGE:	20100920
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
Document 1 - file: doc4.html

Document 1 - RAW XML: doc4.xml

</DOCUMENT>
</SEC-DOCUMENT>