<SEC-DOCUMENT>0001193125-19-074931-index.html : 20190314
<SEC-HEADER>0001193125-19-074931.hdr.sgml : 20190314
<ACCEPTANCE-DATETIME>20190314170033
ACCESSION NUMBER:		0001193125-19-074931
CONFORMED SUBMISSION TYPE:	SC 13D
PUBLIC DOCUMENT COUNT:		2
FILED AS OF DATE:		20190314
DATE AS OF CHANGE:		20190314
GROUP MEMBERS:		BIOGEN SWITZERLAND HOLDINGS GMBH

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Nightstar Therapeutics plc
		CENTRAL INDEX KEY:			0001711675
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			X0
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13D
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-90131
		FILM NUMBER:		19681772

	BUSINESS ADDRESS:	
		STREET 1:		C/O NIGHTSTAR, INC.
		STREET 2:		203 CRESCENT STREET, SUITE 303
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02453
		BUSINESS PHONE:		781-778-7553

	MAIL ADDRESS:	
		STREET 1:		C/O NIGHTSTAR, INC.
		STREET 2:		203 CRESCENT STREET, SUITE 303
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02453

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Nightstar Therapeutics Ltd
		DATE OF NAME CHANGE:	20170712

FILED BY:		

	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 13D

	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
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13D
<SEQUENCE>1
<FILENAME>d700791dsc13d.htm
<DESCRIPTION>SC 13D
<TEXT>
Document 1 - file: d700791dsc13d.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-1.01
<SEQUENCE>2
<FILENAME>d700791dex101.htm
<DESCRIPTION>EX-1.01
<TEXT>
Document 2 - file: d700791dex101.htm

</DOCUMENT>
</SEC-DOCUMENT>