Addition of rituximab in relapsed/refractory chronic lymphocytic leukemia after progression on venetoclax monotherapy

Abstract Venetoclax is approved as monotherapy and in combination with rituximab for relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL). Two Phase 1 studies (M12‐175 [NCT01328626]; M13‐365 [NCT01682616]) were conducted in which patients who initially responded and then progressed on venetoclax monotherapy could receive added rituximab. Ten patients were evaluated (M12‐175, n = 8; M13‐365, n = 2), and five (50%) responded again upon addition of rituximab, including three complete and two partial responses. Responses were ongoing after 5–10 months of follow‐up. Addition of rituximab was well tolerated. These findings indicate potential clinical benefit with rituximab added to venetoclax post‐progression in some patients with R/R CLL.