The current clinical study will explore whether FAK inhibition (defactinib/VS-6063) can be safely and tolerably combined with PD-1 blockade (pembrolizumab), with early indications of improved anticancer immunotherapy from this novel combination. The investigators will focus on three key tumour types, all cancers in clear need of improved therapies. NSCLC, aiming to augment the moderate monotherapy activity of PD-1 blockade; pancreatic cancer, aiming to release immunological activity in this otherwise resistant cancer; and, finally, mesothelioma, where emerging data suggests both agents may have monotherapy activity, including a potential additional mode of action via synthetic lethality of FAK inhibition in the ~50% of mesothelioma with NF2 mutation.