Alfasigma acquires GSK’s liver disease drug Linerixibat for USD690M deal

ITALY—Italian drugmaker Alfasigma has agreed to purchase global rights to linerixibat, GSK’s experimental liver disease treatment, in a transaction valued at up to USD 690 million.

The agreement transfers worldwide development, manufacturing, and commercialization responsibilities for the drug to Alfasigma.

Linerixibat targets cholestatic pruritus in patients with primary biliary cholangitis (PBC).

The experimental medicine works as an ileal bile acid transporter (IBAT) inhibitor, blocking bile acid reuptake through targeted oral therapy.

Payment structure tied to regulatory milestones

The deal’s financial structure links payments to regulatory approvals and commercial performance.

Alfasigma will pay GSK USD 300 million upfront, with an additional USD 100 million due upon US Food and Drug Administration (FDA) approval.

GSK anticipates American regulatory clearance before the transaction closes, with a Prescription Drug User Fee Act (PDUFA) target date set for March 24, 2026.

Beyond the initial payments, GSK stands to receive USD20 million following approvals in the European Union and United Kingdom.

The British drugmaker can also earn up to USD270 million through sales-based milestone payments, plus tiered double-digit royalties on worldwide net sales.

Addressing a challenging liver condition

Primary biliary cholangitis represents a cholestatic liver disease that disrupts bile flow from the liver.

This disruption causes excess bile acids to accumulate in the bloodstream, triggering cholestatic pruritus—an intense internal itch that scratching cannot relieve.

This debilitating symptom can emerge at any disease stage and affects up to 90% of PBC patients.

Currently, physicians prescribe cholestyramine, a bile acid sequestrant, as the first-line treatment for cholestatic pruritus.

However, medical experts disagree on the drug’s efficacy and tolerability.

Strong clinical trial results support approval

Regulatory agencies are reviewing linerixibat based on data from the Phase III GLISTEN trial.

In this study, GSK’s drug delivered significant itch improvement compared to placebo over 24 weeks, achieving the primary endpoint.

The trial also met key secondary measures, including a reduction in itch score at week two and decreased sleep interference due to itching.

Linerixibat has received orphan drug designations in the United States, the European Union, and Japan for the treatment of cholestatic pruritus in PBC patients.

Chinese regulators have granted the drug priority review status.

Strategic focus shift for both companies

Tony Wood, GSK’s chief scientific officer, expressed confidence that Alfasigma’s PBC expertise makes them the ideal partner to advance this treatment.

He noted the agreement allows GSK to concentrate on developing next-generation liver disease therapies, including potential treatments for chronic hepatitis B, metabolic dysfunction-associated steatohepatitis (MASH), and alcohol-related liver disease (ALD).

These conditions collectively cause two million deaths annually and place a substantial strain on healthcare systems.

Alfasigma significantly expanded its PBC portfolio after purchasing Intercept Pharmaceuticals for USD 794 million in 2023.

That acquisition has encountered challenges, as Intercept’s sole approved product, Ocaliva, was withdrawn from PBC markets following re-evaluations of the data.

Most recently, in January 2025, Alfasigma secured global rights to Innovative Molecules’ herpes simplex virus encephalitis candidate, committing up to €125 million (USD144 million) to the licensing agreement.