Corporate Presentation Oppenheimer Healthcare Conference March 16, 2021 Forward-looking Statements 2 This presentation contains forward-looking statements as defined in the Private Securities Litigation Reform Act of 1995 regarding, among other things, the design, initiation, timing and submission to the U.S. Food and Drug Administration (FDA) of a New Drug Application (NDA) for tebipenem HBr and the potential approval of tebipenem HBr by the FDA; future commercialization, the potential number of patients w ...

Spero Therapeutics, Inc. (NASDAQ:SPRO) Q4 2020 Earnings Conference Call March 11, 2021 4:30 PM ET Company Participants Sharon Klahre – Vice President of Investor Relations and Strategic Finance Ankit Mahadevia – Chief Executive Officer David Melnick – Chief Medical Officer Cristina Larkin – Chief Operating Officer Sath Shukla – Chief Financial Officer Conference Call Participants Lyla Youssef – Cowen & Company Louise Chen – Cantor Fitzgerald Kevin DeGeeter – Oppenheimer Esther Hong – Berenberg Ram Selvaraju ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2020 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from ____to____ Commission file number 001-38266 SPERO THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) | Delaware | 46-4590683 | | --- | --- | ...

Corporate Presentation Evercore ISI HealthCONx Conference December 3, 2020 Forward-looking Statements This presentation contains forward-looking statements as defined in the Private Securities Litigation Reform Act of 1995 regarding, among other things, the design, initiation, timing and submission to the U.S. Food and Drug Administration (FDA) of a New Drug Application (NDA) for tebipenem HBr and the potential approval of tebipenem HBr by the FDA; future commercialization, the potential number of patients ...

Tebipenem HBr (SPR994) - Oral Carbapenem - Tebipenem HBr's ADAPT-PO Phase 3 trial met its primary endpoint, demonstrating non-inferiority to IV ertapenem in complicated urinary tract infections (cUTI) and acute pyelonephritis (AP), with similar safety results [5] - The overall combined response rate in the ADAPT-PO trial was 58.8% for oral tebipenem HBr versus 61.6% for IV ertapenem, a difference of -3.3% [21] - The company plans to submit an NDA for Tebipenem HBr in 2Q21 for the treatment of cUTI [5, 11] - If approved, Tebipenem HBr could address a multi-billion dollar opportunity in cUTI and NTM markets, with no approved branded or generic oral competition in the carbapenem class [6] - The carbapenem market is estimated at $3 billion in the United States alone [51] SPR720 - Oral Therapy for NTM Infections - SPR720 is a potential first oral therapy for non-tuberculous mycobacterial (NTM) infections, with orphan drug designation, and initiation of patient dosing in a Phase 2 study planned by YE20 [5] - More than 75% of NTM patients are non-refractory and lack any approved options to treat NTM [95] SPR206 - Novel Therapy for MDR Gram-Negative Infections - SPR206 is a novel therapy for multidrug-resistant (MDR) Gram-negative infections, with a Phase 1 BAL study planned for 1H21 [5] Financial Status - As of September 30, 2020, the company had $127.244 million in cash, cash equivalents, and marketable securities, funding operations into the first quarter of 2022 [118]

Spero Therapeutics, Inc. (NASDAQ:SPRO) Q3 2020 Earnings Conference Call November 5, 2020 4:30 PM ET Company Participants Sharon Klahre – Vice President of Investor Relations and Strategic Finance Ankit Mahadevia – Chief Executive Officer David Melnick – Chief Medical Officer Cristina Larkin – Chief Operating Officer Steve DiPalma – Interim Chief Financial Officer Conference Call Participants Carvey Leung – Cantor Vishal Sethi – Cowen Ellen Sands – Stifel Operator Operator Good day, and welcome to the Spero ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2020 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-38266 SPERO THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) ( State or other jurisdiction of inco ...

Spero Therapeutics, Inc. (NASDAQ:SPRO) Q2 2020 Earnings Conference Call August 6, 2020 4:30 PM ET Company Participants Sharon Klahre – Senior Director-Investor Relations Ankit Mahadevia – Co-Founder, President and Chief Executive Officer David Melnick – Chief Medical Officer Cristina Larkin – Chief Operating Officer Steve DiPalma – Interim Chief Financial Officer Conference Call Participants Ritu Baral – Cowen Louise Chen – Cantor Stephen Willey – Stifel Ram Selvaraju – H.C. Wainwright Chi Fong – Bank of Am ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Commission File Number: 001-38266 SPERO THERAPEUTICS, INC. Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2020 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to (Exact name of registrant as specified in its charter) ( State or other jurisdiction of incorpora ...

Corporate Presentation Bank of America Healthcare Conference May 13, 2020 Forward-looking Statements 2 This presentation contains forward-looking statements as defined in the Private Securities Litigation Reform Act of 1995 regarding, among other things, the initiation, timing, progress and results of the Company's preclinical studies and clinical trials and its research and development programs, including management's assessment of such results; regulatory activities, including the Company's expectation th ...