Merck KGaA buys into a race with Deciphera

Germany’s Merck KGaA clearly sees potential in the rare, benign condition known as tenosynovial giant cell tumour (TGCT), today giving China’s Abbisko $70m for rights to the latter’s small-molecule CSF-1R inhibitor pimicotinib. The big question remains whether TGCT can support one, let alone three, players. That’s what the state of play could look like if pimicotinib reaches the market, as it would likely come after two other oral CSF-1R drugs: Daiichi Sankyo’s currently approved Turalio, and Deciphera’s vimseltinib, which in October scored in phase 3. Still, Merck’s focus is regional: the Abbisko deal covers China and related territories, with western markets subject to a future option. Notably, Turalio isn’t approved outside the US, and Deciphera has no presence in China, its vimseltinib studies being similarly west-focused. Pimicotinib’s phase 3 Maneuver trial ends in May 2026, and it’s not clear how much data from it Merck will have seen. The German group’s interest appears to have been piqued by last month’s phase 1 data at the CTOS meeting, where Abbisko boasted of an 88% ORR in 32 TGCT patients enrolled into a 50mg QD pimicotinib cohort. This compares favourably against the 44-64% ORR vimseltinib showed in phase 1.

Clinical-stage small-molecule CSF-1R inhibitors for tenosynovial giant cell tumour

Note: *also inhibits Kit & Flt3. Source: OncologyPipeline.