LONDON, June 18, 2026, 15:11 BST
- GSK traded at 1,935 pence, down 1.9%, during a broad decline in London equities.
- The FDA approved Utebzi as the first oral carbapenem for certain adults with complicated urinary tract infections.
- A late-2026 launch, a targeted label and no stand-alone sales forecast limit the immediate earnings impact.
GSK shares fell nearly 2% on Thursday despite U.S. approval for Utebzi, a new oral antibiotic aimed at hard-to-treat urinary tract infections. The stock was down 37.5 pence at 1,935 pence as of 15:06 BST, compared with a 0.87% decline in the FTSE 100 shortly before 15:00. The broader market weakened after the Bank of England held rates at 3.75% and the U.S. Federal Reserve signalled a more hawkish policy path.
The regulatory decision removes a significant development risk for GSK’s anti-infectives pipeline. Still, the market response was restrained. Investors now need evidence on pricing, hospital adoption and how quickly prescriptions can turn into material revenue.
The Food and Drug Administration approved Utebzi, or tebipenem pivoxil, for adults with complicated urinary tract infections, including kidney infections known as pyelonephritis, who have limited or no alternative oral treatments. A carbapenem is a broad-spectrum antibiotic used against serious or drug-resistant bacteria; until now, the class had been available in the United States only through intravenous treatment.
In a late-stage trial involving 1,690 hospitalised patients, Utebzi produced results comparable with intravenous imipenem-cilastatin. The study was designed to show “non-inferiority”, meaning the oral medicine was not meaningfully less effective than the established treatment. Amanda Peppercorn, who leads the programme at GSK, said the drug was intended to serve patients already within the “carbapenem footprint with an oral option”, rather than widen the overall treatment pool. GSK has projected that Utebzi, Blujepa and Brexafemme could together generate more than £2 billion in peak annual sales — the highest yearly revenue it expects the group of drugs to reach. Reuters
GSK said more than 3 million complicated urinary tract infections are treated in the United States each year, with treatment failure affecting as many as 34% of patients. The company expects Utebzi to become available by the end of 2026 under its licensing partnership with Spero Therapeutics. Tony Wood, GSK’s chief scientific officer, said the oral drug could “help reduce reliance on hospital-based intravenous care”. GSK
The approval supports a business increasingly reliant on specialty medicines. GSK’s first-quarter specialty-medicine sales rose 14% at constant exchange rates, led by growth in respiratory treatments, oncology and HIV products. The company has forecast 2026 turnover growth of 3% to 5%, with core earnings per share expected to rise 7% to 9%.
Utebzi is a relatively contained commercial launch compared with the larger strategic bets made under Chief Executive Luke Miels. GSK this month agreed to acquire cancer-drug developer Nuvalent for $10.6 billion as it tries to narrow the oncology gap with AstraZeneca and prepare for the 2028 patent expiry of its key HIV medicine dolutegravir. James Eugene, an analyst at Verso Investment Management, said the size of that deal may have surprised investors accustomed to smaller acquisitions.
There are limits to the Utebzi opportunity. Its approval covers patients with few suitable oral alternatives, the launch remains several months away and GSK has not disclosed an individual peak-sales forecast. Hospital controls intended to preserve powerful antibiotics and slow resistance may also curb routine prescribing. Safety monitoring will matter; the FDA lists diarrhoea, headache, nausea and abdominal pain among the most common adverse reactions.
The stock move therefore gives a mixed read. The broad FTSE decline accounts for part of the fall, but GSK still underperformed the index by roughly one percentage point. That suggests the approval was largely expected, or was too small to change near-term earnings assumptions. It is not, on one afternoon’s trading, a clear verdict on Utebzi’s eventual commercial value.
