<SEC-DOCUMENT>0000895345-17-000338-index.html : 20171115
<SEC-HEADER>0000895345-17-000338.hdr.sgml : 20171115
<ACCEPTANCE-DATETIME>20171115164732
ACCESSION NUMBER:		0000895345-17-000338
CONFORMED SUBMISSION TYPE:	SC 13G
PUBLIC DOCUMENT COUNT:		2
FILED AS OF DATE:		20171115
DATE AS OF CHANGE:		20171115
GROUP MEMBERS:		MERCK SHARP & DOHME CORP.
GROUP MEMBERS:		MRL VENTURES FUND LLC

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Spero Therapeutics, Inc.
		CENTRAL INDEX KEY:			0001701108
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-90168
		FILM NUMBER:		171205694

	BUSINESS ADDRESS:	
		STREET 1:		675 MASSACHUSETTS AVENUE
		STREET 2:		14TH FLOOR
		CITY:			CAMBRIDGE
		STATE:			MA
		ZIP:			02139
		BUSINESS PHONE:		857-242-1600

	MAIL ADDRESS:	
		STREET 1:		675 MASSACHUSETTS AVENUE
		STREET 2:		14TH FLOOR
		CITY:			CAMBRIDGE
		STATE:			MA
		ZIP:			02139

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Spero Therapeutics, LLC
		DATE OF NAME CHANGE:	20170316

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Merck & Co., Inc.
		CENTRAL INDEX KEY:			0000310158
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				221918501
		STATE OF INCORPORATION:			NJ
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G

	BUSINESS ADDRESS:	
		STREET 1:		2000 GALLOPING HILL ROAD
		CITY:			KENILWORTH
		STATE:			NJ
		ZIP:			07033
		BUSINESS PHONE:		908-740-4000

	MAIL ADDRESS:	
		STREET 1:		2000 GALLOPING HILL ROAD
		CITY:			KENILWORTH
		STATE:			NJ
		ZIP:			07033

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Merck & Co. Inc.
		DATE OF NAME CHANGE:	20091103

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	SCHERING PLOUGH CORP
		DATE OF NAME CHANGE:	19920703
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G
<SEQUENCE>1
<FILENAME>jb13g-spero_merck.htm
<TEXT>
Document 1 - file: jb13g-spero_merck.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.1
<SEQUENCE>2
<FILENAME>jb13gmerck-ex99_1.htm
<TEXT>
Document 2 - file: jb13gmerck-ex99_1.htm

</DOCUMENT>
</SEC-DOCUMENT>