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, 2024 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 State or other juri ...

Pre-specified interim analysis of Phase 3 PIVOT-PO clinical trial of tebipenem HBr in complicated urinary tract infection (cUTI) is expected to be completed in Q2 2025Company expects to complete analysis of full data set from the Phase 2 study of SPR720 for treatment of Nontuberculous Mycobacterial Pulmonary Disease (NTM-PD) and determine next steps for the programSPR206, a Phase 2 ready program for hospital and ventilator acquired bacterial pneumonia (HABP/VABP), discontinued following a review and reprior ...

CAMBRIDGE, Mass., March 18, 2025 (GLOBE NEWSWIRE) -- Spero Therapeutics, Inc. (Nasdaq: SPRO), a multi-asset clinical-stage biopharmaceutical company, focused on identifying and developing novel treatments for rare diseases and multi-drug resistant (MDR) bacterial infections, today announced that it will report its financial results for the fourth quarter and full year ended December 31, 2024, and provide a business update, on March 27, 2025. Management will host a conference call and live audio webcast to d ...

CAMBRIDGE, Mass., Feb. 25, 2025 (GLOBE NEWSWIRE) -- Spero Therapeutics, Inc. (Nasdaq: SPRO) (Spero), a multi-asset clinical-stage biopharmaceutical company, focused on identifying and developing novel treatments for rare diseases and multi-drug resistant (MDR) bacterial infections, today announced that Esther Rajavelu, Spero’s Interim President and Chief Executive Officer, management will present and will be available for one-on-one meetings at the TD Cowen 45th Annual Health Care Conference being held in B ...

Core Insights - Spero Therapeutics, Inc. is a clinical-stage biopharmaceutical company focused on developing treatments for rare diseases and multi-drug resistant bacterial infections [1][3] - Esther Rajavelu, the Interim President and CEO of Spero, will present at the TD Cowen 45 Annual Health Care Conference in Boston from March 3 to 5, 2025 [1][2] Company Overview - Spero Therapeutics is headquartered in Cambridge, Massachusetts, and is engaged in identifying and developing novel treatments for rare diseases and MDR bacterial infections [3] - The company provides an opportunity for one-on-one meetings during the conference, indicating a proactive approach to investor relations [1][2] Event Details - The company presentation is scheduled for March 5, 2025, at 3:10 PM ET [2] - A webcast of the presentation will be available on Spero Therapeutics' website, with a replay accessible after the event [2]

Core Viewpoint - Spero Therapeutics, Inc. (SPRO) has received an upgrade to a Zacks Rank 2 (Buy) due to an upward trend in earnings estimates, which is a significant factor influencing stock prices [1][3]. Earnings Estimates and Stock Price Impact - The Zacks rating system is based on changes in earnings estimates, which are strongly correlated with near-term stock price movements [4][6]. - Rising earnings estimates for Spero Therapeutics indicate an improvement in the company's underlying business, likely leading to an increase in stock price [5][10]. Zacks Rating System - The Zacks Rank stock-rating system classifies stocks into five groups based on earnings estimates, with a strong historical performance, particularly for Zacks Rank 1 stocks, which have generated an average annual return of +25% since 1988 [7][9]. - The upgrade of Spero Therapeutics to Zacks Rank 2 places it in the top 20% of Zacks-covered stocks, suggesting potential for market-beating returns in the near term [10]. Earnings Estimate Revisions for Spero Therapeutics - For the fiscal year ending December 2024, Spero Therapeutics is expected to earn -$1.20 per share, reflecting a year-over-year change of -379.1% [8]. - Over the past three months, the Zacks Consensus Estimate for Spero Therapeutics has increased by 48.5%, indicating positive sentiment among analysts [8].

Financial Position - Estimated cash and cash equivalents as of December 31, 2024, are approximately $52.9 million[4]. - The company expects its existing cash and cash equivalents, along with non-contingent development milestone payments from GSK, to fund operations into mid-2026[4]. - The complete quarterly results will be included in the Annual Report on Form 10-K for the year ended December 31, 2024[5]. - The company has not yet finalized its financial statements for the year ended December 31, 2024, and the preliminary data may change[5]. Leadership Changes - Interim leadership changes include Esther Rajavelu appointed as Interim President and CEO, with additional cash compensation of $20,000 per month[19]. - Frank Thomas has been appointed as Chairman of the Board, replacing Ankit Mahadevia[19]. - Satyavrat Shukla is on paid administrative leave pending the resolution of the SEC investigation[19]. SEC Investigation - The company is under investigation by the SEC regarding public disclosures related to the cessation of commercialization of tebipenem HBr[10]. - The company intends to vigorously defend against the SEC's Wells Notice and maintain that its disclosures were appropriate[13]. Investor Relations - The company has updated its investor presentation as of January 10, 2025, which is available on its website[8].

Tebipenem HBr Development - Tebipenem HBr is an investigational oral carbapenem antibiotic being developed for the treatment of complicated urinary tract infections (cUTI), including acute pyelonephritis (AP), with the potential to reduce hospitalizations or shorten in-patient therapy [1] - The Phase 3 PIVOT-PO trial for Tebipenem HBr, a global randomized, double-blind study comparing its efficacy with intravenous imipenem cilastatin, began enrolling patients in January 2024 and aims to enroll approximately 2,648 participants, with full enrollment expected by the second half of 2025 [5][14] - As of December 31, 2024, over 60% of the enrollment target for the PIVOT-PO trial has been achieved [14] SPR720 and SPR206 Programs - SPR720 is an oral prodrug converted to SPR719, targeting the ATPase site of DNA gyrase B in mycobacteria, offering a distinct mechanism for treating Non-Tuberculous Mycobacterial-Pulmonary Disease (NTM-PD) [2] - A Phase 2a proof-of-concept trial for SPR720 concluded enrollment in July 2024 with 25 patients, but interim analysis indicated it did not meet its primary endpoint, and safety data highlighted potential dose-limiting issues [14] - SPR206, an investigational intravenous polymyxin, has shown activity against multidrug-resistant (MDR) Gram-negative pathogens and received FDA clearance for a Phase 2 trial in hospital-acquired or ventilator-associated bacterial pneumonia (HABP/VABP), contingent on non-dilutive funding [8] Leadership and Corporate Updates - Esther Rajavelu was appointed Interim President and CEO, and Frank Thomas was named Chairman of the Board, following leadership changes in response to a Wells Notice from the SEC related to 2022 disclosures [9][10] - The company maintains that its disclosures were appropriate and is cooperating with the SEC, intending to vigorously defend against the matter [4][10] - The Board expressed confidence in the interim leadership and the company's strategy to advance its pipeline, including the Tebipenem HBr program [7] Financial and Operational Guidance - As of December 31, 2024, the company had $52.9 million in cash and cash equivalents, with a cash runway extending into mid-2026, supported by non-dilutive funding commitments and milestone payments from GSK [13] - The company remains focused on advancing its Tebipenem HBr clinical program and other ongoing activities, leveraging its financial resources to maintain operational momentum [7][13] Research and Development Support - Select studies for Tebipenem HBr and SPR206 have received funding from federal agencies, including the Department of Health and Human Services and the Department of Defense, highlighting the strategic importance of these programs [6][16][22]

Core Viewpoint - Spero Therapeutics, Inc. (SPRO) is experiencing a downtrend with a 9.3% decline over the past four weeks, but it is in oversold territory, suggesting a potential turnaround due to analysts' positive earnings outlook [1] Group 1: Technical Indicators - The Relative Strength Index (RSI) is a key technical indicator used to identify oversold stocks, with a reading below 30 indicating oversold conditions [2] - SPRO's current RSI reading is 27.37, suggesting that the heavy selling pressure may be exhausting, indicating a possible price rebound [5] Group 2: Fundamental Indicators - There is a strong consensus among sell-side analysts regarding SPRO, with a 6.3% increase in the consensus EPS estimate over the last 30 days, which typically correlates with price appreciation [6] - SPRO holds a Zacks Rank 1 (Strong Buy), placing it in the top 5% of over 4,000 ranked stocks based on earnings estimate revisions and EPS surprises, further supporting the potential for a near-term turnaround [7]

Core Viewpoint - Spero Therapeutics reported a quarterly loss of $0.32 per share, which was worse than the Zacks Consensus Estimate of a loss of $0.27, marking an earnings surprise of -18.52% [1] Financial Performance - The company posted revenues of $13.47 million for the quarter ended September 2024, missing the Zacks Consensus Estimate by 41.44%, and down from $25.47 million in the same quarter last year [2] - Over the last four quarters, Spero Therapeutics has surpassed consensus EPS estimates two times [2] - The current consensus EPS estimate for the upcoming quarter is -$0.21 on revenues of $9 million, and for the current fiscal year, it is -$1.38 on revenues of $51.5 million [7] Stock Performance - Spero Therapeutics shares have declined approximately 10.9% since the beginning of the year, contrasting with the S&P 500's gain of 25.5% [3] - The stock currently holds a Zacks Rank 2 (Buy), indicating expectations of outperforming the market in the near future [6] Industry Outlook - The Medical - Biomedical and Genetics industry, to which Spero Therapeutics belongs, is currently in the top 29% of over 250 Zacks industries, suggesting a favorable outlook [8]