Spero Therapeutics, Inc. (SPRO)

Over the past six months, Spero Therapeutics' stock price surged in July 2025 after Spero Therapeutics and GSK announced that the pivotal Phase 3 PIVOT-PO study for Tebipenem HBr was stopped early due to demonstrated efficacy. In August 2025, Spero Therapeutics anticipated a $23.75 million milestone payment from its collaboration with GSK. In October 2025, continued market optimism was observed following the positive Phase 3 PIVOT-PO trial data for tebipenem HBr, and Spero Therapeutics announced presentations on Tebipenem HBr at IDWeek. In November 2025, Spero Therapeutics reported its third-quarter 2025 operating results, showing a net loss of $7.4 million and total revenue of $5.4 million, and GSK filed the New Drug Application resubmission for Tebipenem HBr with the FDA, while insider selling by CEO and COO was reported. From December 2025 to January 2026, the stock experienced fluctuations, with positive movements driven by ongoing market optimism regarding tebipenem HBr's potential, but modest selling pressure and routine market volatility were also noted. Overall, the share price increased by 168.70% from January 13, 2025, to January 9, 2026.

As a clinical-stage biopharmaceutical company, the demand for Spero Therapeutics' products and services is primarily driven by medical need, regulatory approvals, and market adoption following commercialization, rather than typical seasonal consumer patterns. No explicit information regarding demand seasonality for Spero Therapeutics' specific products or services was found.

Spero Therapeutics, Inc. is a clinical-stage biopharmaceutical company focused on developing novel treatments for multi-drug resistant bacterial infections and rare diseases, operating within the Biotechnology and Pharmaceuticals industry. Its major product candidates include Tebipenem HBr, an oral carbapenem-class antibiotic in Phase 3 development for complicated urinary tract infections, partnered with GSK; SPR720, a novel oral antimicrobial agent under development for nontuberculous mycobacterial pulmonary disease; and SPR206, an intravenously-administered next-generation polymyxin designed to treat severe MDR Gram-negative infections in hospital settings.

Spero Therapeutics is headquartered in Cambridge, Massachusetts, United States, with operations extending to Malta, the UK, the US, and Australia. Through licensing agreements, Spero Therapeutics also has a presence for the development, manufacturing, and commercialization of SPR206 in Greater China, South Korea, and Southeast Asian countries with Everest Medicines.

Spero Therapeutics' brand reputation over the past year has been influenced by its clinical progress and strategic partnerships, with a substantial increase in its stock price suggesting positive investor sentiment. Positive drivers include the positive Phase 3 trial results for Tebipenem HBr and its anticipated FDA approval, the partnership with GSK, and the company's commitment to advancing innovative therapies for rare diseases and MDR bacterial infections and is actively working towards ESG reporting. Potential concerns include reported net losses and decreased collaboration/grant revenue in Q3 2025, insider selling activity, projected net losses for 2024 and 2025, and challenges with the SPR720 program. Analysts currently hold a "Hold" consensus rating for the stock, with an average score of 2.00, though one analyst recommended a "Strong Buy" as of January 12, 2026.

Spero Therapeutics' ownership is distributed among institutional, individual (insider), and retail investors, with institutional shareholders holding approximately 20.08% to 25.60% of the stock and insider ownership ranging from 5.50% to 63.90%. Major institutional owners include Pfizer Inc., Vanguard Group Inc., Anson Funds Management LP, Renaissance Technologies Llc, BlackRock, Inc., Geode Capital Management, Llc, and Alphabet Inc. Significant individual and insider owners include Aquilo Capital Management LLC, GSK PLC, Glaxosmithkline PLC, Jean Francois Formela, Vikas Goyal, and Sath Shukla. In the three months leading up to October 2025, insiders collectively sold more of their company's stock than they purchased.