GSK (GSK) and Spero Therapeutics (SPRO) said Wednesday that the US Food and Drug Administration has approved Utebzi as treatment for complicated urinary tract infections, including pyelonephritis, in adults.

Utebzi, or tebipenem pivoxil, is the first and only oral carbapenem antibiotic approved in the US and is expected to become available by the end of 2026, the companies said.

The approval was based on phase 3 trial data showing Utebzi's non-inferiority to intravenous imipenem-cilastatin, with tebipenem pivoxil achieving an overall success rate of 58.5% against 60.2% for imipenem-cilastatin, according to a statement. Tebipenem pivoxil's safety profile is also "generally similar" to that of imipenem-cilastatin, the companies said.

GSK shares were up about 1%, while Spero stock was down more than 14% in Wednesday trading.

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