GSK and Spero Therapeutics Complete Promising Phase 3 Study on Oral Antibiotic for cUTI

GlaxoSmithKline ((GSK)), GlaxoSmithKline plc (UK) ((GB:GSK)), Spero Therapeutics ((SPRO)) announced an update on their ongoing clinical study.

GlaxoSmithKline (GSK) and Spero Therapeutics have recently completed a Phase 3 clinical study titled A Phase 3, Randomized, Double-blind, Double-dummy, Multicenter, Multinational Study to Assess the Efficacy and Safety of Orally Administered Tebipenem Pivoxil Hydrobromide (TBP-PI-HBr) Compared to Intravenously Administered Imipenem-cilastatin in Patients With Complicated Urinary Tract Infection (cUTI) or Acute Pyelonephritis (AP). The study aimed to evaluate the efficacy of oral TBP-PI-HBr against IV imipenem-cilastatin in treating hospitalized adults with cUTI or AP, focusing on clinical cure and microbiological eradication.

The study tested two interventions: TBP-PI-HBr, an oral film-coated tablet, and imipenem-cilastatin, an IV-administered sterile powder. TBP-PI-HBr was compared to the well-established imipenem-cilastatin to determine its effectiveness as an oral treatment alternative.

This interventional study employed a randomized, parallel assignment model with triple masking (participant, investigator, outcomes assessor) to ensure unbiased results. The primary purpose was treatment, aiming to offer a new oral option for serious urinary tract infections.

The study began on December 21, 2023, and was last updated on June 30, 2025. These dates mark the actual start and the latest update of the study, indicating its progress and completion status.

The completion of this study could significantly impact GSK and Spero Therapeutics’ market positions, potentially boosting investor confidence and stock performance if TBP-PI-HBr proves effective. This development could also influence the competitive landscape in the pharmaceutical industry, particularly in the antibiotics market.

The study is completed, with further details available on the ClinicalTrials portal.