<SEC-DOCUMENT>0001193125-18-247901.txt : 20180814
<SEC-HEADER>0001193125-18-247901.hdr.sgml : 20180814
<ACCEPTANCE-DATETIME>20180814080910
ACCESSION NUMBER:		0001193125-18-247901
CONFORMED SUBMISSION TYPE:	8-K
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20180814
ITEM INFORMATION:		Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers: Compensatory Arrangements of Certain Officers
ITEM INFORMATION:		Financial Statements and Exhibits
FILED AS OF DATE:		20180814
DATE AS OF CHANGE:		20180814

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:		8-K
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-38266
		FILM NUMBER:		181014375

	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>8-K
<SEQUENCE>1
<FILENAME>d607089d8k.htm
<DESCRIPTION>FORM 8-K
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<Center><DIV STYLE="width:8.5in" align="left">
 <P STYLE="line-height:1.0pt;margin-top:0pt;margin-bottom:0pt;border-bottom:1px solid #000000">&nbsp;</P>
<P STYLE="line-height:3.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1px solid #000000">&nbsp;</P> <P STYLE="margin-top:4pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>UNITED STATES </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>SECURITIES AND EXCHANGE COMMISSION </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>Washington, D.C. 20549 </B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center>
<P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>Form <FONT
STYLE="white-space:nowrap">8-K</FONT> </B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center>
<P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>CURRENT
REPORT </B></P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>Pursuant to Section&nbsp;13 or 15(d) </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>of the Securities Exchange Act of 1934 </B></P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:12pt; font-family:Times New Roman" ALIGN="center"><B>Date of Report (Date of earliest event reported): August&nbsp;14, 2018 </B></P>
<P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center> <P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:24pt; font-family:Times New Roman" ALIGN="center"><B>SPERO THERAPEUTICS, INC. </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>(Exact Name of registrant as specified in its charter) </B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center>
<P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:8pt" ALIGN="center">


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<TD VALIGN="top" ALIGN="center"><B>Delaware</B></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top" ALIGN="center"><B><FONT STYLE="white-space:nowrap">001-38266</FONT></B></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top" ALIGN="center"><B><FONT STYLE="white-space:nowrap">46-4590683</FONT></B></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:8pt">
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(State or other jurisdiction</B></P>
<P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>of incorporation)</B></P></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(Commission</B></P>
<P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>File Number)</B></P></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(IRS Employer</B></P>
<P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>Identification No.)</B></P></TD></TR>
</TABLE> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>675 Massachusetts Avenue, 14th Floor </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Cambridge, Massachusetts 02139 </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(Address of principal executive offices and zip code) </B></P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Registrant&#146;s telephone number, including area code: (857) <FONT STYLE="white-space:nowrap">242-1600</FONT> </B></P>
<P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center> <P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Check the appropriate box below if the Form <FONT STYLE="white-space:nowrap">8-K</FONT> filing is intended to simultaneously satisfy the filing obligation of
the registrant under any of the following provisions: </P> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR style = "page-break-inside:avoid">
<TD WIDTH="4%" VALIGN="top" ALIGN="left">&#9744;</TD>
<TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) </P></TD></TR></TABLE>
<P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR style = "page-break-inside:avoid">
<TD WIDTH="4%" VALIGN="top" ALIGN="left">&#9744;</TD>
<TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">Soliciting material pursuant to Rule <FONT STYLE="white-space:nowrap">14a-12</FONT> under the Exchange Act (17
CFR <FONT STYLE="white-space:nowrap">240.14a-12)</FONT> </P></TD></TR></TABLE> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR style = "page-break-inside:avoid">
<TD WIDTH="4%" VALIGN="top" ALIGN="left">&#9744;</TD>
<TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left"><FONT STYLE="white-space:nowrap">Pre-commencement</FONT> communications pursuant to Rule <FONT
STYLE="white-space:nowrap">14d-2(b)</FONT> under the Exchange Act (17 CFR <FONT STYLE="white-space:nowrap">240.14d-2(b))</FONT> </P></TD></TR></TABLE> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR style = "page-break-inside:avoid">
<TD WIDTH="4%" VALIGN="top" ALIGN="left">&#9744;</TD>
<TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left"><FONT STYLE="white-space:nowrap">Pre-commencement</FONT> communications pursuant to Rule <FONT
STYLE="white-space:nowrap">13e-4(c)</FONT> under the Exchange Act (17 CFR <FONT STYLE="white-space:nowrap">240.13e-4(c))</FONT> </P></TD></TR></TABLE>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (17 CFR &#167;230.405) or
Rule <FONT STYLE="white-space:nowrap">12b-2</FONT> of the Securities Exchange Act of 1934 (17 CFR <FONT STYLE="white-space:nowrap">&#167;240.12b-2).</FONT> </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Emerging growth company&nbsp;&nbsp;&#9746; </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">If an emerging
growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section&nbsp;13(a) of the Exchange
Act.&nbsp;&nbsp;&#9746; </P> <P STYLE="font-size:10pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="line-height:1.0pt;margin-top:0pt;margin-bottom:0pt;border-bottom:1px solid #000000">&nbsp;</P>
<P STYLE="line-height:3.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1px solid #000000">&nbsp;</P>
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<TD WIDTH="10%" VALIGN="top" ALIGN="left"><B>Item&nbsp;5.02</B></TD>
<TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left"><B>Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain
Officers;&nbsp;Compensatory Arrangements of Certain Officers. </B></P></TD></TR></TABLE> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">On August&nbsp;14, 2018, Mr.&nbsp;Casper Breum, a member of the Board
of Directors (the &#147;Board&#148;) of Spero Therapeutics, Inc. (the &#147;Company&#148;), gave notice of his decision to retire from the Board effective immediately prior to the next regularly scheduled meeting of the Board on September&nbsp;21,
2018, upon the appointment of his successor, as described below. Mr.&nbsp;Breum&#146;s decision to resign from the Board is not a result of any disagreement with the Company or the Board. </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">On August&nbsp;14, 2018, the Board, upon the recommendation of the Nominating and Corporate Governance Committee, appointed John C. Pottage, Jr., M.D. to the
Board effective immediately prior to the next regularly scheduled meeting of the Board on September&nbsp;21, 2018, concurrent with Mr.&nbsp;Breum&#146;s resignation. Dr.&nbsp;Pottage will serve as a Class&nbsp;I Director for the remainder of the
Class&nbsp;I term, which is up for reelection at the Company&#146;s 2021 annual meeting of stockholders. It is expected that Dr.&nbsp;Pottage will chair the newly established Development Committee and will be added to the Board&#146;s Audit
Committee. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Dr.&nbsp;Pottage has served as Senior Vice President and Chief Scientific and Medical Officer of ViiV Healthcare, a pharmaceutical company,
since November 2009. From September 2008 to November 2009, Dr.&nbsp;Pottage served as Senior Vice President, Head of Infectious Disease Medicine Development Center, and from June 2007 to September 2008 served as the Vice President, Global Clinical
Development of Antivirals, at GlaxoSmithKline, a pharmaceutical company. Prior to joining GlaxoSmithKline, Dr.&nbsp;Pottage served as Chief Medical Officer and Senior Vice President of Drug Development of Achillion Pharmaceuticals, a patient-based
pharmaceutical company, from May 2002 to May 2007. From July 1998 to May 2002, Dr.&nbsp;Pottage served as Medical Director of Vertex Pharmaceuticals, a global biotechnology company. </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Dr.&nbsp;Pottage received his M.D. from Saint Louis University School of Medicine and his A.B. in Biology from Colgate University. </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">The Board has affirmatively determined that Dr.&nbsp;Pottage is an independent director pursuant to Nasdaq&#146;s governance listing standards and those
rules&nbsp;and regulations issued pursuant to the Securities Exchange Act of 1934, as amended. There are no arrangements or understandings between Dr.&nbsp;Pottage and any other person pursuant to which Dr.&nbsp;Pottage was appointed as a director.
There are no transactions to which the Company is a party and in which Dr.&nbsp;Pottage has a material interest that are required to be disclosed under Item&nbsp;404(a) of Regulation <FONT STYLE="white-space:nowrap">S-K.</FONT> Dr.&nbsp;Pottage has
not previously held any positions with the Company and has no family relations with any directors or executive officers of the Company. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Dr.&nbsp;Pottage
will be entitled to the standard compensation paid by the Company to all of its <FONT STYLE="white-space:nowrap">non-employee</FONT> directors under the Company&#146;s <FONT STYLE="white-space:nowrap">Non-Employee</FONT> Director Compensation Policy
<FONT STYLE="white-space:nowrap">(pro-rated</FONT> as applicable to reflect the actual time Dr.&nbsp;Pottage will serve on the Company&#146;s Board for the year), a copy of which is filed as Exhibit 10.20 to the Company&#146;s Registration Statement
on Form <FONT STYLE="white-space:nowrap">S-1,</FONT> as amended (File <FONT STYLE="white-space:nowrap">No.&nbsp;333-220858),</FONT> filed by the Company on October&nbsp;23, 2017. </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Dr.&nbsp;Pottage will also enter into an indemnification agreement on the form the Company has entered into with its other
<FONT STYLE="white-space:nowrap">non-employee</FONT> directors, which form is filed as Exhibit 10.4 to the Company&#146;s Registration Statement on Form <FONT STYLE="white-space:nowrap">S-1</FONT> (File
<FONT STYLE="white-space:nowrap">No.&nbsp;333-220858)</FONT> filed by the Company on October&nbsp;6, 2017 and is incorporated herein by reference. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">A copy
of our press release announcing Dr.&nbsp;Pottage&#146;s appointment to the Board is attached hereto as Exhibit 99.1 and incorporated herein by reference. </P> <P STYLE="font-size:18pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD WIDTH="10%" VALIGN="top" ALIGN="left"><B>Item&nbsp;9.01</B></TD>
<TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left"><B>Financial Statements and Exhibits. </B></P></TD></TR></TABLE>
<P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD WIDTH="4%" VALIGN="top" ALIGN="left">(d)</TD>
<TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">Exhibits </P></TD></TR></TABLE> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD VALIGN="top" NOWRAP>99.1</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top"><A HREF="d607089dex991.htm">Press Release dated August&nbsp;14, 2018. </A></TD></TR>
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 <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>SIGNATURE </B></P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned
hereunto duly authorized. </P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD VALIGN="bottom" COLSPAN="3"><B>SPERO THERAPEUTICS, INC.</B></TD></TR>
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<TD VALIGN="top">Date: August&nbsp;14, 2018</TD>
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<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom">By:</TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom"> <P STYLE="margin-top:0pt; margin-bottom:1pt; border-bottom:1px solid #000000; font-size:10pt; font-family:Times New Roman">/s/ Joel Sendek</P></TD></TR>
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<TD VALIGN="bottom">Name:</TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom">Joel Sendek</TD></TR>
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<TD VALIGN="bottom">&nbsp;</TD>
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<TD VALIGN="bottom">Title:</TD>
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<TD VALIGN="bottom">Chief Financial Officer and Treasurer</TD></TR>
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<TYPE>EX-99.1
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<FILENAME>d607089dex991.htm
<DESCRIPTION>EX-99.1
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<Center><DIV STYLE="width:8.5in" align="left">
 <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="right"><B>Exhibit 99.1 </B></P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>Spero Announces Appointment of John C. Pottage, Jr., MD to its Board of Directors </B></P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><I>Spero adds broad leadership and scientific expertise to its Board of Directors with appointment of John Pottage </I></P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">CAMBRIDGE, Mass. August&nbsp;14, 2018 &#151; Spero Therapeutics, Inc. (Nasdaq:SPRO), a multi-asset clinical-stage biopharmaceutical company focused on
identifying, developing and commercializing novel treatments for multidrug-resistant bacterial infections, today announced the appointment of John C. Pottage, Jr., M.D. to its Board of Directors, effective immediately prior to the next regularly
scheduled meeting of the Board of Directors on September&nbsp;21, 2018. Dr.&nbsp;Pottage has more than 20 years of corporate leadership and scientific experience within the biotechnology and pharmaceutical sectors, currently serving as Senior Vice
President and Chief Scientific and Medical Officer of ViiV Healthcare, where he oversees research and development, regulatory, safety and medical affairs. Dr.&nbsp;Pottage is succeeding Casper Breum, who has been a long-standing director of Spero
since it was a private company and is making a planned transition from the Board, effective upon Dr.&nbsp;Pottage&#146;s appointment. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">&#147;We are
excited to welcome John to our Board of Directors,&#148; said&nbsp;Ankit Mahadevia, M.D., Chief Executive Officer of&nbsp;Spero Therapeutics. &#147;John&#146;s expansive development, operational, and leadership experience within the infectious
disease field will help guide Spero as we continue the rapid advancement of our clinical-stage pipeline in an effort to bring novel therapies to market that address the growing threat of multidrug-resistant bacteria.&#148; </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Dr.&nbsp;Mahadevia added, &#147;We would also like to thank Casper for his many contributions to Spero&#146;s Board over the last three years as we&#146;ve
emerged into a multi-asset public company.&#148; </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Prior to joining ViiV Healthcare, Dr.&nbsp;Pottage served as Senior Vice President and Head of the
Infectious Disease Medicine Development Center at GlaxoSmithKline from September 2008 to November 2009, and prior to that, from June 2007 to September 2008, as Vice President of Global Clinical Development of Antivirals at GlaxoSmithKline. From May
2002 to May 2007, Dr.&nbsp;Pottage served as Chief Medical Officer and Senior Vice President of Drug Development of Achillion Pharmaceuticals. Prior to Achillion Pharmaceuticals, Dr.&nbsp;Pottage served as Medical Director of Vertex Pharmaceuticals,
and in various positions at Rush University Medical Center. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">&#147;This is a transformational time for the company with the initiation of a pivotal Phase
3 trial for SPR994 expected around <FONT STYLE="white-space:nowrap">year-end</FONT> and multiple clinical catalysts on the horizon,&#148; Dr.&nbsp;Pottage said. &#147;I&#146;m delighted to join the Board and look forward to working with the
management team and the board to advance Spero&#146;s robust pipeline.&#148; </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Dr.&nbsp;Pottage presently serves on the advisory board of Medicines for
Malaria Venture in Geneva, Switzerland. He received his A.B. in biology from Colgate University and his M.D. from Saint Louis University School of Medicine. </P>
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 <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>About Spero </B></P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Spero is a multi-asset, clinical-stage biopharmaceutical company focused on identifying, developing and commercializing novel treatments for
multidrug-resistant (&#147;MDR&#148;) bacterial infections. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Spero&#146;s lead product candidate, SPR994, is designed to be the first broad-spectrum oral
carbapenem-class antibiotic for use in adults to treat MDR Gram-negative infections. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Spero also has a platform technology known as its Potentiator
Platform that it believes will enable it to develop drugs that will expand the spectrum and potency of existing antibiotics, including formerly inactive antibiotics, against Gram-negative bacteria. Spero&#146;s lead product candidates generated from
its Potentiator Platform are two intravenous, or IV,-administered agents, SPR741 and SPR206, designed to treat MDR Gram-negative infections in the hospital setting. </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Spero is also advancing SPR720, its novel oral therapy product candidate designed for the treatment of pulmonary
<FONT STYLE="white-space:nowrap">non-tuberculous</FONT> mycobacterial infection. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">For more information, visit <I>https://sperotherapeutics.com</I>. </P>
<P STYLE="margin-top:18pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>Forward-Looking Statements </B></P> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">This press release may
contain forward-looking statements.&nbsp;These statements include, but are not limited to, statements about the initiation, timing, progress and results of Spero&#146;s preclinical studies and clinical trials and its research and development
programs, including statements regarding management&#146;s assessment of the results of such preclinical studies and clinical trials, the timing of clinical data, Spero&#146;s cash forecast and anticipated expenses, the sufficiency of its cash
resources and the availability of additional <FONT STYLE="white-space:nowrap">non-dilutive</FONT> funding from governmental agencies beyond any initially funded awards.&nbsp;In some cases, forward-looking statements can be identified by terms such
as &#147;may,&#148; &#147;will,&#148; &#147;should,&#148; &#147;expect,&#148; &#147;plan,&#148; &#147;aim,&#148; &#147;anticipate,&#148; &#147;could,&#148; &#147;intent,&#148; &#147;target,&#148; &#147;project,&#148; &#147;contemplate,&#148;
&#147;believe,&#148; &#147;estimate,&#148; &#147;predict,&#148; &#147;potential&#148; or &#147;continue&#148; or the negative of these terms or other similar expressions.&nbsp;Actual results may differ materially from those indicated by such
forward-looking statements as a result of various important factors, including whether results obtained in preclinical studies and clinical trials will be indicative of results obtained in future clinical trials; whether Spero&#146;s product
candidates will advance through the preclinical development and clinical trial process on a timely basis, or at all; whether the results of such trials will warrant submission for approval from the&nbsp;United States Food and Drug
Administration&nbsp;or equivalent foreign regulatory agencies; whether Spero&#146;s cash resources will be sufficient to fund its continuing operations for the periods and/or trials anticipated; and other factors discussed in the &#147;Risk
Factors&#148; set forth in filings that we periodically make with the U.S. Securities Exchange Commission.&nbsp;The forward-looking statements included in this press release represent Spero&#146;s views as of the date of this press
release.&nbsp;Spero anticipates that subsequent events and developments will cause its views to change.&nbsp;However, while Spero may elect to update these forward-looking statements at some point in the future, it specifically disclaims any
obligation to do so.&nbsp;These forward-looking statements should not be relied upon as representing Spero&#146;s views as of any date subsequent to the date of this press release. </P>
 <p STYLE="margin-top:0pt;margin-bottom:0pt ; font-size:8pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">2 </P>

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 <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><B>Spero Investor Contact: </B></P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Sharon Klahre </P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Director, Investor Relations </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><FONT STYLE="white-space:nowrap"><FONT STYLE="white-space:nowrap">857-242-1547</FONT></FONT> </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman"><I><U>IR@sperotherapeutics.com </U></I></P>
 <p STYLE="margin-top:0pt;margin-bottom:0pt ; font-size:8pt">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">3 </P>

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