GSK agreed to sell worldwide rights to linerixibat to Alfasigma for 300 million dollars upfront, plus 100 million upon US FDA approval, with potential milestone and sales-based payments tied to performance.

Alfasigma will obtain worldwide exclusive rights to develop, manufacture, and commercialize linerixibat for cholestatic pruritus in primary biliary cholangitis (PBC).

GSK will receive tiered double-digit royalties on worldwide net sales of linerixibat.

Linerixibat targets severe itching associated with cholestatic pruritus in PBC, an autoimmune liver disease affecting bile ducts.

Linerixibat is an experimental treatment for cholestatic pruritus in PBC, with potential to relieve itch in affected patients.

Marketing applications rely on positive results from the GLISTEN phase III trial, which showed rapid, significant, and sustained improvement in cholestatic pruritus and itch-related sleep interference versus placebo, with a safety profile typical of IBAT inhibition.

Linerixibat is investigational and not approved anywhere globally at the time of the announcement.

Linerixibat has not yet received regulatory approval in any market.

GSK will use proceeds from the deal to focus on other programs, including chronic hepatitis B and alcoholic liver disease, which together account for millions of deaths annually.

Linerixibat has Orphan Drug Designation in the US, EU, and Japan, and priority review in China for the treatment of cholestatic pruritus in PBC.

Linerixibat is an investigational IBAT inhibitor under regulatory review in multiple regions, with orphan designation in major markets and priority review in China for PBC-related pruritus.

At market close, GSK shares edged higher, trading around 2,043 pence.