Efficacy and safety of bosutinib (BOS) for Philadelphia chromosome–positive (Ph+) leukemia in older versus younger patients (pts).

6511 Background: BOS is an oral dual Src/Abl kinase inhibitor with potent activity in Ph+ leukemia. Methods: Efficacy and safety of BOS 500 mg/d was evaluated in older (≥65 y; n = 119) and younger (<65 y; n = 451) pts in 3 cohorts: chronic phase chronic myeloid leukemia (CP CML) after imatinib (IM; CP2L cohort; n = 287); CP CML after IM + dasatinib (DAS) and/or nilotinib (NIL; CP3L cohort; n = 119); and accelerated/blast phase (AP/BP) CML or acute lymphoblastic leukemia after IM ± DAS and/or NIL (ADV cohort; n = 164). Results: Baseline events (≥65 y vs <65 y) included respiratory disorders (35% vs 13%), cardiac disorders (29% vs 9%), and diabetes (4% vs 4%). Median baseline medicatio…