Spero Therapeutics stock surges after positive Phase 3 UTI drug data

Published 21/10/2025, 15:00
© Reuters.

Investing.com -- Spero Therapeutics (NASDAQ:SPRO) stock rose 7% on Tuesday after the company and partner GSK (NYSE:GSK) announced positive Phase 3 trial results for tebipenem HBr, a potential first-in-class oral carbapenem antibiotic for complicated urinary tract infections (cUTIs).

The pivotal PIVOT-PO trial, which was stopped early for efficacy in May, demonstrated that oral tebipenem HBr was non-inferior to intravenous imipenem-cilastatin in treating hospitalized patients with cUTIs, including pyelonephritis. The oral treatment achieved a 58.5% overall success rate compared to 60.2% for the intravenous option, with an adjusted treatment difference of -1.3%.

The results represent a significant advancement as tebipenem HBr could become the first oral carbapenem antibiotic available in the U.S., potentially reducing the need for hospital stays for the estimated 2.9 million cUTI cases treated annually in the country. Current carbapenem antibiotics are only available in intravenous form.

"These ground-breaking data show for the first time that cUTIs, including pyelonephritis, can be treated with an oral carbapenem antibiotic as effectively as with an intravenous one," said Tony Wood, Chief Scientific Officer at GSK, which has licensed tebipenem HBr from Spero for development and commercialization in most global markets.

The safety profile was generally comparable to other carbapenem antibiotics, with diarrhea and headache reported as the most common adverse events, all of which were mild to moderate and non-serious.

GSK plans to submit regulatory filings in Q4 2025 based on these results. The drug has already received Qualified Infectious Disease Product and Fast Track designations from the FDA, potentially expediting its review process.

This article was generated with the support of AI and reviewed by an editor. For more information see our T&C.

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