<SEC-DOCUMENT>0001193125-19-104620-index.html : 20190412
<SEC-HEADER>0001193125-19-104620.hdr.sgml : 20190412
<ACCEPTANCE-DATETIME>20190412090555
ACCESSION NUMBER:		0001193125-19-104620
CONFORMED SUBMISSION TYPE:	FWP
PUBLIC DOCUMENT COUNT:		2
FILED AS OF DATE:		20190412
DATE AS OF CHANGE:		20190412

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:		FWP
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	333-229377
		FILM NUMBER:		19745323

	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

FILED BY:		

	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:		FWP

	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>FWP
<SEQUENCE>1
<FILENAME>d679106dfwp.htm
<DESCRIPTION>FWP
<TEXT>
Document 1 - file: d679106dfwp.htm
</DOCUMENT> <DOCUMENT> <TYPE>GRAPHIC <SEQUENCE>2 <FILENAME>g679106g0412105457160.jpg <DESCRIPTION>GRAPHIC <TEXT> Document 2 - file: g679106g0412105457160.jpg
</DOCUMENT> </SEC-DOCUMENT>