Anthony Mato, MD, Memorial Sloan Kettering Cancer Center, New York, NY presents the results of the BRUIN Phase I/II trial (NCT 03740529) of LOXO-305 in patients with B-cell malignancies. LOXO-305 is a highly selective, non-covalent BTK inhibitor that targets both wildtype and C481-mutated BTK, overcoming substantial limitations of current covalent BTKis. 186 previously treated patients were enrolled, with B-cell malignancies including chronic lymphocytic leukemia (CLL), mantle cell lymphoma, and diffuse large B-cell lymphoma. 7 dose levels were used in the dose-escalation study, but there were no dose reductions or dose-limiting toxicities. Results show a high overall response rate, deepening over time in those with ≥6 months follow up. LOXO-305 was very well tolerated, showed promising activity, and a recommended Phase II dose of 200mg QD was established. This interview took place during the 62nd American Society of Hematology (ASH) Annual Meeting and Exposition, 2020.