Open Access

Renato Bassan, Dieter Hoelzer, Xavier Thomas, Pau Montesinos, Jiri Pavlu, Jan McKendrick, Amber Kudlac, Arie Barlev, Beth Barber, Ze Cong

• Introduction: Despite the poor prognosis for adults with relapsed or refractory (RR) Philadelphia chromosome (Ph)-negative B cell 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 B cell 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. Funding: Amgen Inc.