Spero Therapeutics Inc. and GSK plc have announced positive efficacy and safety results from the pivotal Phase 3 PIVOT-PO trial evaluating tebipenem HBr, an investigational oral treatment for complicated urinary tract infections (cUTIs), including pyelonephritis. The results were presented on October 20, 2025, during a late-breaking oral abstract session at IDWeek 2025 in Atlanta, Georgia. The trial met its primary endpoint, demonstrating non-inferiority of oral tebipenem HBr compared to intravenous imipenem-cilastatin. Secondary endpoints showed clinical cure rates of 93.5% for tebipenem HBr and 95.2% for imipenem-cilastatin, as well as similar microbiological response rates. Spero and GSK plan to submit the data to regulatory authorities in Q4 2025. If approved, tebipenem HBr would be the first oral carbapenem antibiotic available in the US for patients with cUTIs.