PLX51107 (2 mg/kg, p.o.) inhibits splenomegaly by 75% in the Ba/F3 (murine IL3-dependent pro-B-cell line) splenomegaly mouse model, with the similar effect of 25 mg/kg OTX015. PLX51107 (20 mg/kg, qd, p.o.) exhibits potent antileukemic effects in disease models of aggressive chronic lymphocytic leukemia (CLL) and Richter transformation (RT) via oral administration once daily[1].