Need for consensus on primary endpoints and efficacy definitions in trials for adult acute lymphoblastic leukemia

A lack of consensus on acceptable primary endpoints and definitions of response and survival in Phase II/III efficacy studies for adult acute lymphoblastic leukemia has led to widely different clinical trial designs. Inconsistency in primary endpoint selection and lack of consensus on response, survival endpoints, and adequate follow-up time leads to difficulty interpreting completed studies and developing future trials. Lack of consensus also runs a risk of integrating ineffective or unacceptably toxic regimens into clinical practice and future trials. Increasingly, studies integrating highly-active, targeted agents into chemotherapy are using short-term endpoints of response, MRD-negative response, and early event-free survival without confidence that these endpoints will translate into improved late patient outcomes. This article highlights current consequences and dilemmas caused by this lack of consensus. The hope is to stimulate discussion and ultimately consensus to improve interpretation and application of clinical trial results.