GSK, Spero stop UTI drug trial after early success

May 28 (Reuters) - Spero Therapeutics SPRO.O and partner GSK GSK.L are stopping a late-stage trial of an experimental oral drug for complicated urinary tract infections early as the study met its main goal, the companies said on Wednesday.

Shares of Spero more than tripled to $2.24 in premarket trading.

The decision comes after a recommendation from an independent committee that completed an interim analysis of data from 1,690 patients enrolled in the trial.

The companies were studying the oral drug, tebipenem HBr, as a treatment for complicated urinary tract infections (cUTIs), including a type of kidney infection called pyelonephritis.

An estimated 2.9 million cases of cUTIs are treated annually in the U.S. alone.

The current standard of care includes antibiotics called carbapenem, but those are only available for intravenous administration.

In the trial, the drug showed it was at least as good as an intravenous imipenem-cilastatin, a type of antibiotic, in hospitalized adult patients.

If approved, the drug could be the first oral carbapenem antibiotic for patients with cUTIs.

The review by the committee did not identify any new safety concerns beyond what had been reported in other studies, with diarrhea and headache as the two most reported side effects.

The companies had entered into a licensing agreement for the development of tebipenem HBr in 2022.

The U.S. FDA had previously declined to approve the drug saying a late-stage study testing it was insufficient and an additional study would be required.

The British drugmaker plans to work with U.S. regulatory authorities to include the data as part of a filing in the second half of the year.

Full results will be submitted for presentation at an upcoming scientific congress and for publication in a peer-reviewed journal, the companies said.