Study of TNG260 and an Anti-PD Antibody in STK11 Mutated Solid Tumors

The goal of this interventional clinical trial is to learn about TNG260, a CoREST inhibitor, in combination with pembrolizumab in patients with advanced solid tumors with a known STK11 mutation. The main question\[s\] it aims to answer are: * the recommended dose for Phase 2 * to evaluate the safety and tolerability of the combination therapy * to determine the pharmacokinetics of TNG260 * to evaluate the initial antineoplastic activity Participants will receive study treatment until they experience an undesirable side effect, their disease progresses or until they withdraw consent.