<SEC-DOCUMENT>0001104659-19-006789-index.html : 20190208
<SEC-HEADER>0001104659-19-006789.hdr.sgml : 20190208
<ACCEPTANCE-DATETIME>20190208155245
ACCESSION NUMBER:		0001104659-19-006789
CONFORMED SUBMISSION TYPE:	SC 13G/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20190208
DATE AS OF CHANGE:		20190208

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BIOGEN INC.
		CENTRAL INDEX KEY:			0000875045
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		IRS NUMBER:				330112644
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-42028
		FILM NUMBER:		19579711

	BUSINESS ADDRESS:	
		STREET 1:		225 BINNEY STREET
		CITY:			CAMBRIDGE
		STATE:			MA
		ZIP:			02142
		BUSINESS PHONE:		7814642000

	MAIL ADDRESS:	
		STREET 1:		225 BINNEY STREET
		CITY:			CAMBRIDGE
		STATE:			MA
		ZIP:			02142

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	BIOGEN IDEC INC.
		DATE OF NAME CHANGE:	20070427

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	BIOGEN IDEC INC
		DATE OF NAME CHANGE:	20031112

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	IDEC PHARMACEUTICALS CORP / DE
		DATE OF NAME CHANGE:	19970530

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:		177 EAST COLORADO BLVD.
		STREET 2:		11TH FLOOR
		CITY:			PASADENA
		STATE:			CA
		ZIP:			91105
		BUSINESS PHONE:		6263049222

	MAIL ADDRESS:	
		STREET 1:		177 EAST COLORADO BLVD.
		STREET 2:		11TH FLOOR
		CITY:			PASADENA
		STATE:			CA
		ZIP:			91105
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G/A
<SEQUENCE>1
<FILENAME>a19-4191_8sc13ga.htm
<DESCRIPTION>SC 13G/A
<TEXT>
Document 1 - file: a19-4191_8sc13ga.htm

</DOCUMENT>
</SEC-DOCUMENT>