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# GSK and Spero’s Antibiotic Positive Phase 3 Results
- URL: https://www.fdaweb.com/gsk-and-speros-antibiotic-positive-phase-3-results/
- Published: 2025-10-21T12:00:00.000Z
- Updated: 2026-09-14T15:24:39.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5160075

GSK and Spero Therapeutics are announcing positive Phase 3 results for tebipenem HBr, an investigational oral antibiotic for complicated urinary tract infections (cUTIs), including pyelonephritis. The findings are from the pivotal PIVOT-PO trial, which was stopped early for efficacy following a recommendation from an independent data monitoring committee. The companies said they plan to submit the data to FDA in the fourth quarter.

The late-stage PIVOT-PO trial compared oral tebipenem HBr (600 mg) with intravenous imipenem-cilastatin (500 mg) in 1,690 hospitalized adults with cUTI or pyelonephritis. Tebipenem HBr achieved a 58.5% overall success rate — defined as a composite of clinical cure and bacterial eradication — compared to 60.2% for imipenem-cilastatin, meeting the prespecified non-inferiority margin, according to the companies. Secondary endpoints also showed comparable performance — clinical cure: 93.5% (tebipenem) vs. 95.2% (IV imipenem), and microbiological response: 60.3% vs. 61.3%, respectively.

The oral drug’s safety profile was similar to that of IV carbapenem-class antibiotics, the companies say, adding that the most common adverse events were mild or moderate diarrhea and headache.