A comparison of CR versus CRi response following CPX-351 treatment of newly diagnosed AML in elderly patients (pts).

6601 Background: A Phase 2b study randomized untreated elderly AML pts to CPX-351 or 7+3. CPX-351 improved leukemia clearance (88% v 71%, 20K (27% v 15%), and more adverse karyotype (40% v 27%) and sAML (47% v 29%). A smaller proportion of CRi pts received post-remission chemotherapy (47% v 73%) but had similar rates of SCT (13% v 20%). Most CRi pts had delayed platelet recovery (80%). By 1-year more CRi pts had relapsed (54% v 39%) and more had died (54% v 34%). Contributing causes included: relapsed AML (7 CRi v 10 CR pts), complications post SCT (1 CRi v 1 CR pt), chemotherapy complications (0 CRi v 2 CR pts) and unknown causes (0 CRi v 1 CR pt). The survival curves were not significantly different (p=0.39). Conclusions: More CRi patients had adverse karyotype and sAML and most (53%) received no post remission chemotherapy. Survival was not significantly different compared to CR patients but was markedly better than that of non-responders. These data suggest that CRi following CPX-351 provides clinically meaningful benefit, a finding that needs to be confirmed in a larger randomized study.