CDK2 and plasma cell myeloma: AT7519 is a pyrazole derivative and multi CDK inhibitor, which has proven efficient towards several human cancer cell lines, which is administered to patients with advanced solid tumours or refractory non-Hodgkin’s lymphoma, and which is currently in phase 2 trials for multiple myeloma, CLL and MCL [349,350,351,352,415] NU6140 [320], NU2058 and NU6027 [316,317] are second generation purines which inhibit CDKs more potently through formation of additional hydrogen bonds with CDK2.