Spero Therapeutics Shares Surge Over 200% as Oral Carbapenem Antibiotic Tebipenem HBr Meets Phase 3 Endpoint in cUTI

▎Armstrong

On May 28, 2025, GSK and Spero Therapeutics announced the early termination of the Phase III clinical trial PIVOT-PO for Tebipenem HBr in treating complicated urinary tract infections (cUTIs) due to efficacy. This decision was based on the recommendation from the IDMC following an interim analysis of data from 1,690 patients. Tebipenem HBr is expected to become the first oral carbapenem antibiotic. The Phase III trial met its primary endpoint of non-inferiority compared to intravenous imipenem-cilastatin.

Affected by this news, the pre-market stock price of Spero Therapeutics surged 227%, with a market value reaching 130 million US dollars.

The Phase III clinical trial was originally planned to enroll 2,628 patients.

2022Year9Month22Recently, GlaxoSmithKline PLC. acquired the global rights (excluding Japan and other Asian countries) for Tebipenem HBr. Spero Therapeutics received an upfront payment of $66 million, a $9 million equity investment, and up to an additional $550 million in milestone payments.

Summary

Tebipenem HBr is the core pipeline of Spero Therapeutics. It is an orally available carbapenem antibiotic prodrug that is rapidly converted into the active drug molecule in intestinal cells.