GSK plc has entered into a global licensing agreement with Alfasigma S.p.A., granting the Italian drugmaker exclusive worldwide rights to develop, manufacture and commercialise linerixibat, an investigational therapy for cholestatic pruritus associated with primary biliary cholangitis (PBC).

Under the agreement, GSK will receive an upfront payment of USD 300 million and an additional USD 100 million upon approval of the drug by the US Food and Drug Administration. The company is also eligible for USD 20 million upon regulatory approvals in the EU and UK, along with up to USD 270 million in sales-based milestone payments. GSK will further earn tiered double-digit royalties on global net sales.

Linerixibat is an oral ileal bile acid transporter (IBAT) inhibitor being developed to treat cholestatic pruritus—an intense and persistent itch associated with the rare autoimmune liver disease PBC. The drug works by blocking bile acid re-uptake, reducing circulating mediators believed to trigger the condition.

The therapy has received orphan drug designation in the US, EU and Japan, and is currently under regulatory review in several markets including the US, EU, UK, China and Canada following positive results from the Phase III GLISTEN trial. The study demonstrated significant and sustained improvement in itch severity and sleep disruption compared with placebo.

The licensing deal aligns with GSK’s strategy to focus on advancing its broader pipeline in liver diseases such as chronic hepatitis B, metabolic dysfunction-associated steatohepatitis (MASH) and alcohol-associated liver disease (ALD).

Meanwhile, Alfasigma plans to leverage its hepatology expertise and global commercial network to bring linerixibat to patients suffering from PBC-related itching, a debilitating symptom that can severely affect sleep, daily functioning and quality of life.

The transaction remains subject to customary closing conditions and regulatory approvals, including clearance under US antitrust regulations.