SPERO THERAPEUTICS, INC.
675 Massachusetts Avenue, 14th Floor
Cambridge, Massachusetts 02139
PROXY STATEMENT FOR SPERO THERAPEUTICS, INC.
2023 ANNUAL MEETING OF STOCKHOLDERS TO BE HELD ON OCTOBER 5, 2023
This proxy statement, along with the accompanying Notice of 2023 Annual Meeting of Stockholders, contains information about
the 2023 annual meeting of stockholders of Spero Therapeutics, Inc. (Annual Meeting), including any adjournments or postponements of the Annual Meeting. We are holding the Annual Meeting at 9:00 a.m. Eastern Time on October 5, 2023.
This years annual meeting will be conducted solely via live audio webcast on the Internet. You will be able to attend the annual meeting, vote and submit your questions during the annual meeting by visiting
www.virtualshareholdermeeting.com/SPRO2023. You will not be able to attend the annual meeting in person.
In this proxy
statement, we refer to Spero Therapeutics, Inc. as Spero, the Company, we and us.
This proxy statement relates to the solicitation of proxies by our board of directors (Board of Directors) for use
at the Annual Meeting.
On or about September 1, 2023, we intend to begin sending this proxy statement, the attached
Notice of Annual Meeting of Stockholders and the enclosed proxy card to all stockholders entitled to vote at the Annual Meeting.
Although not part of this proxy statement, we are also sending, along with this proxy statement, our Annual Report on Form 10-K for the fiscal year ended December 31, 2022, as amended, which includes our financial statements for the fiscal year ended December 31, 2022.
IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS FOR THE
SHAREHOLDER MEETING TO BE HELD ON OCTOBER 5, 2023
This proxy statement, the Notice of Annual Meeting of Stockholders, our form of proxy card and our 2022 Annual Report on
Form 10-K are available for viewing, printing and downloading at www.proxyvote.com. To view these materials, please have your 16-digit control
number available that appears on your proxy card. On this website, you can also elect to receive future distributions of our proxy statements and annual reports to stockholders by electronic delivery.
Additionally, you can find a copy of our Annual Report on Form 10-K, which includes
our financial statements, for the fiscal year ended December 31, 2022, on the website of the Securities and Exchange Commission (the SEC), at www.sec.gov, or in the SEC Filings section of the
Investors & Media section of our website at www.sperotherapeutics.com. You may also obtain a printed copy of our Annual Report on Form 10-K, including our financial
statements, free of charge, from us by sending a written request to: Spero Therapeutics, Inc., Attn: Investor Relations, 675 Massachusetts Avenue, 14th Floor, Cambridge, Massachusetts 02139. Exhibits will be provided upon written request and payment
of an appropriate processing fee.