Following years of volatile financial performance and operational losses, Spero Therapeutics has refocused its strategy exclusively on the tebipenem HBr antibiotic program in partnership with GSK. This follows discontinuation of SPR206 and SPR720 programs, streamlining the company’s development efforts amid regulatory and clinical uncertainties. Financially, Spero returned to profitability in 2025, driven primarily by licensing revenues from GSK collaboration despite continued negative operating cash flow. Key risks remain tied to milestone dependencies on GSK, supply chain concentration in Asia, and ongoing regulatory and legal challenges.