LONDON, March 20, 2026, 20:19 GMT
GSK shares edged lower Friday, shedding 0.28% to close at 1,950.5 pence in London. This came just a day after the UK pharmaceutical giant secured U.S. approval for Lynavoy, a new therapy targeting severe itch caused by a rare liver condition.
This green light triggers a $100 million payout to GSK from Italy’s Alfasigma, as laid out in their March 9 licensing agreement. Alfasigma will assume global rights to develop, produce, and market the drug, shifting GSK’s role to collecting milestone checks and royalties based on future sales—not full revenue from the product.
The U.S. Food and Drug Administration has approved Lynavoy for cholestatic pruritus—an intense, stubborn itch—in adults diagnosed with primary biliary cholangitis, or PBC, a rare autoimmune disease that targets the liver. GSK says no other drug has won a U.S. green light for this use. According to Reuters, PBC impacts over 100,000 adults across the country.
GSK describes Lynavoy as an IBAT inhibitor—short for ileal bile acid transporter inhibitor—intended to lower bile acids that cause itching. In the phase 3 GLISTEN study, patients taking the pill saw their itch and sleep scores improve versus placebo across 24 weeks, with effects showing up as early as the second week.
Kaivan Khavandi, who heads R&D at GSK, described Lynavoy as a “much needed treatment option.” Earlier this month, Chief Scientific Officer Tony Wood said transferring linerixibat to Alfasigma “sharpens GSK’s focus” on its other liver projects. Reuters
It’s all part of CEO Luke Miels’ wider strategy. Back in February, GSK reaffirmed its target: topping 40 billion pounds in yearly sales by 2031. The company pointed to fresh product launches as a way to counter upcoming HIV patent cliffs. Still, GSK projected a slowdown for revenue growth in 2026 and flagged uncertainty around vaccines.
Competition is already in play. Gilead’s Livdelzi and Ipsen’s Iqirvo treat PBC, though neither goes after the itch directly. Mirum Pharmaceuticals, on the other hand, has volixibat in the works, aiming specifically at pruritus in PBC.
Risks remain. Details on pricing and launch dates haven’t been released, and the rights transfer is pending standard approvals. Diarrhoea and abdominal pain turned up most frequently as side effects during trials. Regulatory reviews are ongoing in the EU, UK, Canada, and China.
GSK wasn’t immune to Friday’s downturn. The FTSE 100 dropped 1.4%—fears over the Middle East war and climbing oil prices driving inflation anxieties yet again. In that context, GSK’s losses appeared modest versus the rest of the slide.
