<SEC-DOCUMENT>0001193125-18-217909-index.html : 20180713
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<ACCEPTANCE-DATETIME>20180713165114
ACCESSION NUMBER:		0001193125-18-217909
CONFORMED SUBMISSION TYPE:	424B4
PUBLIC DOCUMENT COUNT:		13
FILED AS OF DATE:		20180713
DATE AS OF CHANGE:		20180713

FILER:

	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:		424B4
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	333-226093
		FILM NUMBER:		18952996

	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
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