London – UK pharmaceutical giant GSK has announced an agreement to acquire privately held biotechnology firm IDRx for a total of $1.15 billion. The deal includes a $1 billion upfront payment and an additional $150 million in milestone payments tied to the progress of IRx’s drug pipeline.
Tnargeted Therapy for Gastrointestinal Cancer
The acquisition will provide GSK access to IDRx’s flagship experimental therapy, IDRX-42, aimed at treating gastrointestinal stromal tumors (GIST). This rare form of gastrointestinal cancer is primarily driven by KIT gene mutations, which account for about 80% of cases. GSK noted that IDRX-42 is designed to address all clinically relevant KIT mutations, a significant unmet need in current treatments for GIST.
Approximately 4,000 to 6,000 people in the US are diagnosed with GIST annually, with many developing resistance to first-line therapies due to new KIT mutations. Early data from the phase 1/1b StrateGIST 1 trial revealed a 29% overall objective response rate (ORR) for IDRX-42, which increased to 53% among patients who had received only one prior treatment.
GSK’s Oncology Expansion
This acquisition aligns with GSK’s strategy to strengthen its oncology portfolio, particularly in gastrointestinal cancers. GSK’s Chief Commercial Officer, Luke Miels, stated that IDRX-42 complements existing therapies, including Jemperli (dostarlimab), an anti-PD-1 antibody under development for colorectal cancer, and GSK5764227, a B7-H3-directed antibody-drug conjugate.
Tony Wood, the company’s Chief Scientific Officer, expressed optimism about the potential of IDRX-42 to set a new standard of care for GIST. “We are excited by the early data from IDRX-42 and its unique ability to target all clinically relevant KIT mutations. We look forward to accelerating its development in 2025 to redefine treatment,” he said.
IDRx CEO Tim Clackson echoed this sentiment, emphasizing the significance of collaborating with pharmaceutical company to advance the therapy. “There have been no major advances to the standard of care for almost 20 years. Combining our experience with GSK’s expertise and global capabilities will help accelerate the development of this novel medicine for patients,” Clackson said.
Broader Strategic Context
The IDRx acquisition follows GSK’s $1.9 billion purchase of Sierra Oncology in 2022 and other recent partnerships with Hansoh Pharma, Rgenta Therapeutics, and Duality Biologics. These deals highlight GSK’s efforts to strengthen its oncology pipeline as it prepares for upcoming challenges, including the expiration of patents for key products like dolutegravir, its top-selling HIV drug, in 2027, as well as growing competition for its Shingrix shingles vaccine.
IDRx was launched in 2022 in Plymouth, Massachusetts, by entrepreneurs Ben Auspitz and Alexis Borisy, with Christoph Lengauer serving as a scientific advisor. The company’s first funding round was led by Andreessen Horowitz and Casdin Capital.
Join our Channel...