<SEC-DOCUMENT>0000899243-17-025133-index.html : 20171101
<SEC-HEADER>0000899243-17-025133.hdr.sgml : 20171101
<ACCEPTANCE-DATETIME>20171101192451
ACCESSION NUMBER:		0000899243-17-025133
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20171101
FILED AS OF DATE:		20171101
DATE AS OF CHANGE:		20171101

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Deshpande Milind
		CENTRAL INDEX KEY:			0001378588

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-38266
		FILM NUMBER:		171170313

	MAIL ADDRESS:	
		STREET 1:		ACHILLION PHARMACEUTICALS
		STREET 2:		300 GEORGE STREET
		CITY:			NEW HAVEN
		STATE:			CT
		ZIP:			06511

ISSUER:		

	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

	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
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>doc3.xml
<DESCRIPTION>FORM 3 SUBMISSION
<TEXT>
Document 1 - file: doc3.html

Document 1 - RAW XML: doc3.xml

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-24.1
<SEQUENCE>2
<FILENAME>attachment1.htm
<DESCRIPTION>EX-24.1 DOCUMENT
<TEXT>
Document 2 - file: attachment1.htm

</DOCUMENT>
</SEC-DOCUMENT>