GSK has agreed to acquire IDRx, a Boston-based, clinical-stage bio/pharmaceutical company, in a deal worth up to $1.1 billion ($1 billion upfront and $150 million in milestone payments). 

The acquisition includes IDRx’s lead molecule, IDRX-42, being developed as a first- and second-line therapy for the treatment of gastrointestinal stromal tumors (GIST). IDRX-42 is a highly selective, investigational small-molecule tyrosine kinase inhibitor designed to target all key KIT mutations in GIST. The US Food and Drug Administration has granted IDRX-42 fast-track designation for the treatment of patients with GIST after disease progression on or intolerance to imatinib, and orphan drug designations for the treatment of GIST. 

The acquisition will add to GSK’s portfolio in gastrointestinal cancers, including ongoing trials with dostarlimab and GSK5764227, a B7-H3-targeted antibody-drug conjugate. 

Under the agreement, GSK will acquire 100% of the outstanding equity interests (including all options and other incentive equity) in IDRx for up to $1.15 billion of total cash consideration, comprising an upfront payment of $1 billion with potential for an additional $150 million success-based regulatory approval milestone payment. GSK will also be responsible for success-based milestone payments as well as tiered royalties for IDRX-42 owed to Merck KGaA. The transaction is subject to customary conditions, including applicable regulatory agency clearances under the Hart-Scott-Rodino Act in the US. 

Source: GSK