Continuing its diversification strategy, Merck & Co. has agreed to acquire ArQule, a biopharmaceutical company focused on kinase inhibitors for the treatment with cancers and rare diseases. ArQule’s lead asset is ARQ 531, an orally bioavailable, potent and reversible dual inhibitor of both wild type and C481S-mutant Bruton’s tyrosine kinase, which is currently in a Phase II study for the treatment of B-cell malignancies refractory to other therapeutic options. ArQule is also developing miransertib for the treatment of proteus syndrome and PIK3CA-related overgrowth syndromes, ARQ 751 for solid tumours and derazantinib for intrahepatic cholangiocarcinoma.