GSK, Spero to stop urinary tract infection drug trial due to early success

Spero Therapeutics and GSK are halting their Phase 3 trial of tebipenem HBr, an oral drug for complicated urinary tract infections, due to positive interim results showing the drug is as effective as the current intravenous treatment; Spero shares nearly tripled in premarket trading following the announcement. GSK plans to submit the trial data to U.S. regulators in the second half of the year.

Analysis

Spero Therapeutics (SPRO.O) and its partner GSK (GSK.L) have announced the early termination of their late-stage trial for tebipenem HBr, an experimental oral drug for complicated urinary tract infections (cUTIs), including pyelonephritis, citing positive efficacy results. This decision followed a recommendation from an independent committee's pre-specified interim analysis of data from 1,690 enrolled patients, which demonstrated that tebipenem HBr was at least as effective as an existing intravenous treatment in hospitalized adult patients. The positive news prompted a significant market reaction, with Spero Therapeutics' shares nearly tripling to $2 in premarket trading. GSK intends to utilize this data for a regulatory filing with U.S. authorities in the second half of the year. This development substantially de-risks tebipenem HBr and positions it as a potentially valuable oral alternative to current IV treatments for cUTIs, offering potential benefits in patient convenience and healthcare system efficiency.

Key Decisions for Investors

• Investors in Spero Therapeutics (SPRO) should recognize that while the significant premarket share increase reflects the positive trial outcome, future catalysts will revolve around the successful FDA submission by GSK in H2 2024 and subsequent regulatory review.
• For GSK (GSK.L) investors, this successful trial adds a promising late-stage oral antibiotic to its infectious disease portfolio, potentially enhancing its market position in cUTI treatments, although the immediate financial impact is expected to be more significant for Spero.
• Consider the disruptive potential of an effective oral alternative like tebipenem HBr in the cUTI market, currently reliant on intravenous therapies, and monitor the competitive landscape as GSK moves towards regulatory submission and potential commercialization.