GSK announced that its phase 3 PIVOT-PO study evaluating oral carbapenem antibiotic tebipenem HBr was terminated early after an independent data monitoring committee determined the drug met its primary efficacy endpoint for treating complicated urinary tract infections (cUTIs), including pyelonephritis.
The study compared tebipenem HBr to an intravenous carbapenem regimen of imipenem and cilastatin in hospitalized patients with complicated urinary tract infections. The drug achieved non-inferiority to the IV treatment and demonstrated no new safety concerns beyond those observed in previous research, with the most common side effects being diarrhea and headaches.
Potential First-in-Class Oral Carbapenem
If approved, tebipenem could become the first oral carbapenem antibiotic for complicated UTIs in the United States, representing a significant therapeutic advance for patients with drug-resistant infections. The oral formulation would allow patients to receive treatment at home rather than requiring hospitalization for IV therapy, potentially reducing exposure to hospital-acquired infections.
"Complicated UTIs can have a profound impact on patients and carry a high risk of clinical complications, including sepsis and septic shock," said Tony Wood, GSK's chief scientific officer. Wood noted that many patients currently require hospital-based IV treatment due to limited oral options for drug-resistant infections.
Clinical and Economic Impact
An estimated 2.9 million cases of complicated UTIs are treated annually in the United States, with many requiring hospitalization. The cost of caring for these patients is estimated at approximately $6 billion per year, highlighting the significant healthcare burden of these infections.
The success follows GSK's recent FDA approval of gepotidacin (Blujepa) in March 2024, which became the first oral antibiotic with a new mechanism of action cleared for uncomplicated urinary tract infections in nearly three decades.
Development History and Partnership
GSK acquired rights to tebipenem HBr in 2022 from Spero Therapeutics for $66 million upfront, following the FDA's rejection of Spero's initial application in June 2022. The regulatory agency had requested a second clinical trial after challenging the company's analysis of the original ADAPT-PO study, which compared tebipenem to IV ertapenem in patients with cUTI and acute pyelonephritis.
The licensing agreement includes potential milestone payments of up to $525 million, including $150 million upon completion of the PIVOT-PO trial and $150 million upon first commercial sale in the US or Europe. Spero's stock price more than tripled following the announcement, climbing to approximately $2.15 from a Tuesday close of 68 cents per share.
Regulatory Timeline
GSK plans to submit its FDA application in the second half of 2024, incorporating the new PIVOT-PO data. The PIVOT-PO protocol was specifically designed based on FDA feedback following the initial rejection. The company also intends to present full study results at an upcoming medical meeting and publish findings in a peer-reviewed journal.
The development represents part of GSK's broader infectious disease strategy aimed at addressing the growing challenge of antimicrobial resistance, providing physicians with additional treatment options for drug-resistant bacterial infections.
