GSK-Spero Therapeutics’ Utebzi earns FDA approval to combat rising global antimicrobial resistance

USA—GSK plc and Spero Therapeutics have secured approval from the US Food and Drug Administration (FDA) for Utebzi (tebipenem pivoxil), an oral antibiotic designed to treat complicated urinary tract infections (cUTIs), including pyelonephritis, in adults with limited or no alternative oral options.

The approval marks the first time an oral carbapenem antibiotic has been authorized in the United States, expanding treatment choices for hard-to-treat infections.

The decision follows a regulatory review completed in mid-June 2026 and is based on strong late-stage clinical evidence demonstrating that the therapy performs on par with standard intravenous antibiotics used in hospital settings.

Burden of complicated UTIs and treatment gaps

More than 3 million cases of complicated UTIs are recorded annually in the United States, and treatment failure affects up to one-third of patients.

These infections are frequently driven by multidrug-resistant bacteria, creating significant clinical and economic pressure on healthcare systems.

Annual treatment costs linked to such infections exceed US$6 billion.

Until now, carbapenems have been considered a critical class for severe resistant infections, which are only available as intravenous therapies.

This often required hospital admission, infusion centres, or home-based IV setups, limiting patient convenience and increasing healthcare resource use.

The introduction of tebipenem pivoxil offers a potential oral alternative, allowing more patients to receive treatment outside hospital settings.

Clinical evidence behind the approval

The FDA approval is supported by results from the Phase III PIVOT-PO trial, which enrolled over 1,400 hospitalized adults with cUTIs, including pyelonephritis.

The study showed that oral tebipenem pivoxil achieved an overall success rate of 58.5%, compared with 60.2% for intravenous imipenem-cilastatin, confirming non-inferiority.

The treatment was generally well tolerated, with side effects such as diarrhoea and headache reported in a small proportion of patients and classified as mild or moderate.

Recent regulatory coverage noted that the approval strengthens GSK’s expanding anti-infectives portfolio at a time when antimicrobial resistance continues to rise globally.

Leadership views on the breakthrough

GSK Chief Scientific Officer Tony Wood said the approval addresses a growing need for new options as antibiotic resistance continues to increase.

 He noted that an oral carbapenem could reduce reliance on hospital-based intravenous care while improving treatment access.

At Northwell Health, urology specialist Dr. Bilal Chughtai described the approval as a major step forward for both patients and healthcare providers, highlighting the potential to shift more treatment into outpatient care and reduce hospital burden.

Spero Therapeutics CEO Esther Rajavelu said the approval reflects more than a decade of development work and collaboration with GSK, adding that the partnership aims to expand access to a much-needed oral therapy.

Regulatory path and commercial outlook

The approval follows a long development pathway, including NDA resubmission and priority regulatory review.

The program also received support from the US Department of Health and Human Services through BARDA funding under preparedness initiatives for antimicrobial resistance.

GSK has indicated that Utebzi is expected to become available in the United States by the end of 2026 as manufacturing and distribution scale-up continues.