British drug maker GSK plc (GSK.L, GSK) Monday announced that it has signed an agreement to acquire IDRx, a Boston-based, clinical-stage biopharmaceutical company, for up to $1.15 billion in cash.
The acquisition includes lead molecule IDRX-42, which is a highly selective KIT Tyrosine Kinase Inhibitor being developed as a first- and second-line therapy for treating gastrointestinal stromal tumors or GIST.
The consideration includes $1 billion upfront, with the 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 German drug maker Merck KGaA (MKGAY.PK).
GIST usually occurs in the GI tract, with 80 percent of cases caused by mutations in the KIT gene. The mutations promote the growth and survival of tumor cells. After first-line treatment, 90 percent of patients develop new KIT mutations, leading to relapse and limited treatment options.
Currently, no approved TKIs can target all clinically relevant primary and secondary KIT mutations.
GSK noted that IDRX-42 works against all main KIT mutations, which could help improve outcomes for GIST patients.
Tony Wood, Chief Scientific Officer,GSK, said, "We are excited by the early data from IDRX-42 and its unique ability to target all clinically relevant KIT mutations present in GIST, a major gap in the current standard of care. We look forward to accelerating its development in 2025 to redefine treatment."
GSK is currently trading 0.82% less at 1338.50 pence on the London Stock Exchange.
For comments and feedback contact: editorial@rttnews.com
Business News
April 17, 2026 15:29 ET The ongoing conflict in the Middle East continues to raise concerns for policymakers who worry about the impact of the supply shock and high energy prices on the real economy. Producer price data and various survey results on the housing market were the main news from the U.S. this week. In Europe, industrial production data for the euro area gained attention. GDP figures out of China and the policy move by the Singapore central bank were in focus in Asia.