GSK plc has agreed to transfer global exclusive rights to linerixibat to Alfasigma S.p.A., the companies announced Monday. Under the licensing arrangement, Alfasigma will take responsibility for the development, manufacturing and commercialization of linerixibat, an investigational ileal bile acid transporter - IBAT - inhibitor being pursued as a treatment for cholestatic pruritus in patients with primary biliary cholangitis.
The financial structure of the deal calls for an immediate payment of $300 million to GSK. Additional contingent amounts are payable upon regulatory milestones and sales targets: $100 million tied to U.S. FDA approval, $20 million linked to approvals in the EU and the U.K., and as much as $270 million in sales-based milestone payments. GSK will also receive tiered double-digit royalties on net sales worldwide.
The drug is currently under regulatory review in several major markets, including the United States, the European Union, the U.K., China and Canada. In addition, linerixibat holds Orphan Drug Designation in the U.S., EU and Japan, and has been granted priority review status in China for the indication of cholestatic pruritus in primary biliary cholangitis.
GSK highlighted the transaction as part of a strategic reorientation. The company said the move allows it to concentrate resources on developing treatments for chronic hepatitis B, metabolic dysfunction-associated steatotic hepatitis - MASH - and alcohol-related liver disease - ALD, conditions it noted together account for roughly two million deaths annually, according to the statement from the company's Chief Scientific Officer.
Regulatory filings for linerixibat were supported by positive results from the GLISTEN phase III trial. The study met its primary and key secondary endpoints, demonstrating a rapid, statistically significant and sustained reduction in cholestatic pruritus and improvements in itch-related sleep interference when compared with placebo. Reported safety findings were consistent with prior studies and aligned with the expected effects of IBAT inhibition.
Despite the phase III outcome, linerixibat has not yet received approval anywhere in the world, leaving final regulatory and commercial outcomes in the hands of Alfasigma. The U.S. Food and Drug Administration's PDUFA target action date is set for March 24. Under the terms agreed, GSK will receive the $100 million payment if that U.S. approval is secured.
Context and next steps
Alfasigma will be responsible for progressing pending regulatory reviews, manufacturing scale-up and global commercialization if approvals are granted. GSK will retain a financial interest through milestone payments and royalties tied to future sales performance.