The trial will be conducted in 2 parts: dose escalation (Phase I ) and dose expansion (Phase 2) . During Phase 1, patients with advanced solid tumors are eligible if the tumor has progressed following or has not adequately responded to standard therapy, or if the patient is intolerant of, or unlikely to benefit from or refuses standard therapy. Prior TRK inhibitor therapy is required for patients harboring an NTRK fusion. During Phase 2, the same patient population as designated for Phase 1 will be treated with the dose of LOXO-195 which has been identified during phase 1 to assess specified endpoints.