Complete, yet partial: the benefits of complete response with partial haematological recovery as an endpoint in acute myeloid leukaemia clinical trials

The ideal stepping stone on the path to cure for patients with acute myeloid leukaemia has been the achievement of a complete response (CR), the initial response most consistently associated with long-term survival.1 Some patients who achieve less than CR, however, seem to derive benefit from particular types of therapy. Newly-diagnosed patients with acute myeloid leukaemia who receive intensive induction chemotherapy and achieve CR with incomplete haematological recovery (CRi; defined by the same criteria as CR, but with residual cytopenia such as absolute neutrophil count [ANC] <1000 cells per μL or platelet count <100 000 cells per μL) or CR with incomplete platelet recovery (CRp; similar to CRi, but specifically referring to the absence of platelet recovery) after initial therapy have worse relapse-free survival and overall survival than do patients who achieve CR, but fare better than those without response.