<SEC-DOCUMENT>0001104659-15-010275-index.html : 20150213
<SEC-HEADER>0001104659-15-010275.hdr.sgml : 20150213
<ACCEPTANCE-DATETIME>20150213145531
ACCESSION NUMBER:		0001104659-15-010275
CONFORMED SUBMISSION TYPE:	SC 13G/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20150213
DATE AS OF CHANGE:		20150213

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MOMENTA PHARMACEUTICALS INC
		CENTRAL INDEX KEY:			0001235010
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		IRS NUMBER:				043561634
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-79927
		FILM NUMBER:		15613114

	BUSINESS ADDRESS:	
		STREET 1:		675 WEST KENDALL STREET
		CITY:			CAMBRIDGE
		STATE:			MA
		ZIP:			02142
		BUSINESS PHONE:		617 491-9700

	MAIL ADDRESS:	
		STREET 1:		675 WEST KENDALL STREET
		CITY:			CAMBRIDGE
		STATE:			MA
		ZIP:			02142

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PRIMECAP MANAGEMENT CO/CA/
		CENTRAL INDEX KEY:			0000763212
		IRS NUMBER:				953868081

	FILING VALUES:
		FORM TYPE:		SC 13G/A

	BUSINESS ADDRESS:	
		STREET 1:		225 SOUTH LAKE AVE STE 400
		CITY:			PASADENA
		STATE:			CA
		ZIP:			91101-3005
		BUSINESS PHONE:		8183049222

	MAIL ADDRESS:	
		STREET 1:		225 SOUTH LAKE AVE SUITE 400
		CITY:			PASADENA
		STATE:			CA
		ZIP:			91101
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G/A
<SEQUENCE>1
<FILENAME>a15-4369_36sc13ga.htm
<DESCRIPTION>SC 13G/A
<TEXT>
Document 1 - file: a15-4369_36sc13ga.htm

</DOCUMENT>
</SEC-DOCUMENT>