Spero Therapeutics’ Tebipenem Trial Stops Early After Meeting Efficacy

CAMBRIDGE, Mass., May 28, 2025 (GLOBE NEWSWIRE) — Spero Therapeutics, Inc. (Nasdaq: SPRO) and GSK plc (LSE/NYSE: GSK) announced today that the Phase 3 PIVOT-PO trial evaluating tebipenem HBr, an investigational oral treatment for complicated urinary tract infections (cUTIs), has met its primary endpoint and will stop early for efficacy.

The decision comes after a recommendation from an Independent Data Monitoring Committee (IDMC) that reviewed data from 1,690 patients enrolled in the trial. The trial demonstrated that tebipenem HBr is non-inferior to intravenous imipenem-cilastatin in treating adult patients hospitalized with cUTIs, including pyelonephritis. The assessment evaluated overall response, a combination of clinical cure and microbiological eradication, at the test-of-cure visit.

No new safety concerns were identified during the IDMC review. The most common adverse events reported were diarrhea and headache. GSK, in collaboration with U.S. regulatory authorities, plans to incorporate these findings into a planned filing in the second half of 2025.

Esther Rajavelu, Chief Executive Officer of Spero, expressed enthusiasm about the results. “Achieving the primary endpoint in the PIVOT-PO trial marks a significant milestone for tebipenem HBr. If approved, we believe this treatment has the potential to change the therapeutic landscape for cUTI patients,” she said.

Every year, an estimated 2.9 million cases of cUTIs occur in the U.S., with these infections frequently caused by multi-drug-resistant bacteria. Current treatment options often require intravenous administration, resulting in increased hospitalizations and emergency department visits, costing the U.S. healthcare system over $6 billion annually.

Tony Wood, Chief Scientific Officer at GSK, noted, “Complicated UTIs can significantly impact patients and increase the risk of severe clinical complications. The positive results from this trial add to our anti-infectives portfolio and support tebipenem HBr as an effective oral option that can be taken at home.”

The development of tebipenem HBr is partially supported by federal funds from the U.S. Department of Health and Human Services through the Biomedical Advanced Research and Development Authority (BARDA).