Clinician Concepts of Cure in Adult Relapsed and Refractory Philadelphia-Negative B Cell Precursor Acute Lymphoblastic Leukemia: A Delphi Study

Introduction: Despite the poor prognosis for adults with relapsed or refractory (RR) Philadelphia chromosome (Ph)-negative Bcell precursor acute lymphoblastic leukemia (ALL), long-term survival is possible and may even be considered as cure. Methods: This study used a Delphi panel approach to explore concepts of cure in RR Ph-negative Bcell precursor ALL. Ten European experts in this disease area participated in a survey and face-to-face panel meeting. Results: Findings showed that clinicians conceptualize cure as a combination of three broad treatment outcomes that vary depending on the treatment stage: complete remission early in treatment (1-3 months) indicates initial success; eradicating cancer cells (minimal residual disease negative status) consolidates the early clinical response; leukemia-free survival is required in the long term. Conclusions: Although such terminology remains contested, clinicians would begin considering cure as early as 2 years provided the patient is off therapy, with most considering the term applicable by the third year.