IBTK and B-cell chronic lymphocytic leukemia: Preclinical results show that ARQ-531 had better survival compared to ibrutinib in chronic lymphocytic leukemia (CLL), diffuse large B cell lymphoma (DLBCL) and Richter’s transformation mouse models, and was able to inhibit the activation of both the C418 mutant and PLCy2 mutants in CLL cells, demonstrating activity against BTKi resistance [32].