This is a Phase 1/2, open label, multicenter, multidose, first-in-human (FIH) dose escalation and expansion to determine the safety and tolerability, recommended phase 2 dose and optimal dosing interval, pharmacology, and antitumor activity of RTX-240 in adult patients with relapsed/refractory or locally advanced solid tumors. RTX-240 is a cellular therapy that co-expresses 4-1BBL and IL-15TP, a fusion of IL-15 and IL-15 receptor alpha, with the goal of harnessing the innate and adaptive immune systems for the treatment of cancer. The study will include a monotherapy dose escalation phase followed by an expansion phase in specified tumor types.

