<SEC-DOCUMENT>0001193125-20-030568-index.html : 20200211
<SEC-HEADER>0001193125-20-030568.hdr.sgml : 20200211
<ACCEPTANCE-DATETIME>20200211070159
ACCESSION NUMBER:		0001193125-20-030568
CONFORMED SUBMISSION TYPE:	424B5
PUBLIC DOCUMENT COUNT:		3
FILED AS OF DATE:		20200211
DATE AS OF CHANGE:		20200211

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:		424B5
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	333-228661
		FILM NUMBER:		20593862

	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>424B5
<SEQUENCE>1
<FILENAME>d832850d424b5.htm
<DESCRIPTION>424B5
<TEXT>
Document 1 - file: d832850d424b5.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>2
<FILENAME>g832850g05e18.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 2 - file: g832850g05e18.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>3
<FILENAME>g832850g61v41.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 3 - file: g832850g61v41.jpg

</DOCUMENT>
</SEC-DOCUMENT>