GSK's Strategic Acquisition of IDRx: A Boost to Gastrointestinal Cancer Portfolio

GSK plc (LSE/NYSE: GSK), a global healthcare company, has announced its intention to acquire IDRx, Inc., a Boston-based clinical-stage biopharmaceutical company dedicated to developing precision therapeutics for the treatment of gastrointestinal stromal tumours (GIST). The acquisition, valued at up to $1.15 billion, includes IDRx's lead molecule, IDRX-42, a highly selective KIT tyrosine kinase inhibitor (TKI) designed to treat GIST as a first- and second-line therapy.

IDRX-42 offers potential to address all key KIT mutations in GIST that drive tumour growth and progression, improving tolerability compared to existing therapies. This breadth of mutational coverage, combined with high selectivity, positions IDRX-42 as a potential best-in-class therapy for GIST. The acquisition aligns with GSK's strategy of building up its oncology pipeline through strategic deals, as it prepares to face patent expiry for its HIV drug dolutegravir and competition to its shingles vaccine Shingrix.

GIST is a rare cancer, affecting between 4,000 and 6,000 people in the US each year. Approximately 80% of all GIST cases are driven by mutations in the KIT gene, leading to tumour cell growth, proliferation, and survival. Currently, there are no approved TKIs that inhibit the full spectrum of clinically relevant primary and secondary mutations in KIT. IDRX-42's potential to address all key primary and secondary KIT mutations in GIST could lead to improved outcomes for patients, addressing a significant unmet medical need.

Luke Miels, Chief Commercial Officer at GSK, stated, "IDRX-42 complements our growing portfolio in gastrointestinal cancers. This acquisition is consistent with our approach of acquiring assets that address validated targets and where there is clear unmet medical need, despite existing approved products." Tony Wood, Chief Scientific Officer at GSK, added, "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."



The acquisition of IDRx and its lead molecule, IDRX-42, adds to GSK's growing portfolio in gastrointestinal cancers, which already includes ongoing trials with dostarlimab and GSK5764227 (GSK'227), a B7-H3-targeted antibody-drug conjugate. This expansion supports GSK's ambitions for growth through 2031 and beyond, as it continues to invest in its pipeline and prepare for the future.

In conclusion, GSK's acquisition of IDRx, Inc., and its lead molecule, IDRX-42, is a strategic move that complements GSK's existing portfolio in gastrointestinal cancers. The potential of IDRX-42 to address all key KIT mutations in GIST, combined with its high selectivity, positions it as a promising therapy for this rare and challenging cancer. As GSK continues to invest in its pipeline and prepare for the future, this acquisition is a testament to the company's commitment to addressing unmet medical needs and improving patient outcomes.