PTK2 and mesothelioma: GSK2256098 is a potent, oral, reversible inhibitor of the tyrosine kinase activity measured by the autophosphorylation site (Tyr 397) of FAK.6 In preclinical studies, GSK2256098 was demonstrated to be at least 20 times more active in vitro in Merlin-negative (encoded by NF-2) mesothelioma cells than in Merlin-positive cells.6 In a recent phase I study of GSK2256098 monotherapy for patients with advanced solid tumours, mesothelioma patients with Merlin-negative tumours had a progression-free survival (PFS) nearly twice that of Merlin-positive mesothelioma patients.7