Open Access

Nicola Gökbuget, Gerhard Zugmaier, Hervé Dombret, Anthony Stein, Massimiliano Bonifacio, Carlos Graux, Christoph Faul, Monika Brüggemann, Kate Taylor, Noemi Mergen, Albrecht Reichle, Heinz August Horst, Violaine Havelange, Max S. Topp, Ralf C. Bargou

• Minimal residual disease (MRD) is the strongest predictor of relapse in B-cell precursor acute lymphoblastic leukemia (BCP-ALL). In BLAST study (NCT01207388), adults with BCP-ALL in remission with MRD after chemotherapy received blinatumomab, a CD19 BiTE® immuno-oncotherapy, 15 µg/m2/day for up to four 6-week cycles (4 weeks continuous infusion, 2 weeks off). Survival was evaluated for 110 patients, including 74 who received HSCT in continuous complete remission. With a median follow-up of 59·8 months, median survival (months) was 36·5 (95% CI: 22.0–not reached [NR]). Median survival was NR (29.5–NR) for complete MRD responders (n = 84) and 14.4 (3.8–32.3) for MRD non-responders (n = 23; p = 0.002); after blinatumomab and HSCT, median survival was NR (25.7–NR) (n = 61) and 16.5 (1.1–NR) (n = 10; p = 0.065), respectively. This final analysis suggests complete MRD response during blinatumomab treatment is curative. Post-hoc analysis of study data suggests while post blinatumomab HSCT may be beneficial in appropriate patients, long-term survival without HSCT is also possible.