<SEC-DOCUMENT>0001591986-22-000008-index.html : 20220214
<SEC-HEADER>0001591986-22-000008.hdr.sgml : 20220214
<ACCEPTANCE-DATETIME>20220214155448
ACCESSION NUMBER:		0001591986-22-000008
CONFORMED SUBMISSION TYPE:	SC 13G/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20220214
DATE AS OF CHANGE:		20220214

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/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-90168
		FILM NUMBER:		22630941

	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:			Aquilo Capital Management, LLC
		CENTRAL INDEX KEY:			0001591986
		IRS NUMBER:				272448001
		STATE OF INCORPORATION:			CA
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G/A

	BUSINESS ADDRESS:	
		STREET 1:		ONE LETTERMAN DRIVE
		STREET 2:		SUITE D4900, BUILDING D
		CITY:			SAN FRANCISCO
		STATE:			CA
		ZIP:			94129
		BUSINESS PHONE:		415-635-0140

	MAIL ADDRESS:	
		STREET 1:		ONE LETTERMAN DRIVE
		STREET 2:		SUITE D4900, BUILDING D
		CITY:			SAN FRANCISCO
		STATE:			CA
		ZIP:			94129

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Aquilo Capital Managment, LLC
		DATE OF NAME CHANGE:	20131114
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G/A
<SEQUENCE>1
<FILENAME>spro_13gv1.htm
<TEXT>
Document 1 - file: spro_13gv1.htm

</DOCUMENT>
</SEC-DOCUMENT>