Study of SNX281 in Subjects With Advanced Solid Tumors and Lymphoma

SNX281 is a small molecule activator of the Stimulator of Interferon Genes (STING) protein, with good drug-like properties. Activation of STING initiates the innate immune response and enhances the adaptive immune response, which could potentially activate immune responses to tumors and enhance the response to certain immunotherapies. This study is a phase I, first in human, open-label study of SNX281 conducted in subjects with advanced solid tumors and lymphomas. The study will comprise of two treatment arms: one evaluating SNX281 as a single-agent, and the other evaluating SNX281 in combination with pembrolizumab (KEYTRUDA®). Each treatment arm is designed to include a dose escalation phase followed by a dose expansion phase intended to establish the recommended Phase 2 dose (RP2D). In the dose escalation phase of each treatment arm, successive cohorts of participants will receive increasing doses of SNX281 designed to determine the maximum tolerated dose (MTD), the dose with maximum pharmacologic activity, or the maximum feasible dose, as a single-agent and in combination with pembrolizumab (KEYTRUDA®). The dose expansion phases of each treatment arm will begin following the determination of an MTD or alternative dose of SNX281 in each respective treatment arm. The single-agent treatment arm of SNX281 is planned to evaluate at least 2 expansion cohorts in ovarian cancer and colorectal carcinoma while the combination treatment arm of SNX281 and pembrolizumab (KEYTRUDA®) is planned to enroll subjects with advanced cancer who have relapsed on or have become refractory to prior immune checkpoint therapy given in an indicated setting.