GSK revives rejected antibiotic with phase 3 win for oral UTI treatment

GSK and Spero Therapeutics' oral antibiotic tebipenem HBr met its phase 3 primary endpoint, proving non-inferior to standard IV therapy for complicated urinary tract infections (cUTIs).

Why it matters: An effective oral alternative could shift treatment from hospital to home, reducing healthcare costs and freeing up hospital beds, critical in managing antibiotic-resistant infections.

Backstory: The FDA previously rejected Spero’s application in 2022, citing the need for more data. GSK acquired rights to the drug for $66M and restarted development. The recent trial was stopped early for efficacy.

Zoom in: The non-inferior result of tebipenem HBr is based on a 58.5% success rate vs. 60.2% for IV imipenem-cilastatin. This treatment works against ESBL-producing and levofloxacin-resistant pathogens and resulted in 93.5% of tebipenem patients being symptom-free.

Big picture: If approved, tebipenem HBr would be the first oral carbapenem in the U.S., addressing a major gap in outpatient treatment for drug-resistant infections. However, questions remain about the trial’s reliance on Eastern European data and concerns over pill burden and resistance potential.

What’s next: Spero and GSK´s filing is expected later this year, with Spero to receive $25M in milestone payment upon submission. This can not come soon enough, as there is already a competing oral antibiotic with a lower pill burden being developed by Basilea.