LONDON, March 20, 2026, 20:19 GMT
GSK shares slipped on Friday, a day after the British drugmaker won U.S. approval for Lynavoy, its new treatment for severe itch linked to a rare liver disease. The stock finished down 0.28% at 1,950.5 pence in London. 1
The approval matters now because it unlocks a $100 million payment from Italy’s Alfasigma under GSK’s March 9 licensing deal. Alfasigma is set to take worldwide rights to develop, manufacture and sell the drug, leaving GSK with milestone payments and royalties tied to future sales rather than full product revenue. 2
The U.S. Food and Drug Administration cleared Lynavoy for cholestatic pruritus — a relentless internal itch — in adults with primary biliary cholangitis, or PBC, a rare autoimmune liver disease. GSK said it is the first medicine approved in the United States for that indication, and Reuters reported that PBC affects more than 100,000 U.S. adults. 3
GSK says Lynavoy is an ileal bile acid transporter, or IBAT, inhibitor, a pill designed to reduce bile acids linked to the itch. In the late-stage GLISTEN trial, it improved itch severity and sleep disruption against placebo, a dummy pill, over 24 weeks, with benefits appearing by week two. 3
Kaivan Khavandi, a GSK R&D executive, called Lynavoy a “much needed treatment option.” Earlier this month, Chief Scientific Officer Tony Wood said handing linerixibat to Alfasigma “sharpens GSK’s focus” on other liver programs. 4
That narrower economics still fits a broader plan under new CEO Luke Miels. In February, GSK kept its goal of more than 40 billion pounds in annual sales by 2031 and said new launches would be key to offset looming patent expiries in its HIV business, even as it guided to slower 2026 revenue growth and warned of uncertainty in vaccines. 5
The competitive field is not empty. Gilead’s Livdelzi and Ipsen’s Iqirvo are used for PBC itself but do not directly target the itch, while Mirum Pharmaceuticals is developing volixibat for pruritus in PBC. 4
But there are risks. The companies have not yet detailed pricing or launch timing, the rights transfer still needs customary clearances, and the most common side effects in trials were diarrhoea and abdominal pain. Reviews are also still running in the EU, UK, Canada and China. 4
Friday’s broader market mood did GSK no favours either. London’s FTSE 100 fell 1.4% as the Middle East war and rising oil prices fed inflation worries, which made GSK’s decline look relatively contained against the wider selloff. 6
