Is Immunotherapy Beneficial in Adults with ALL?

Adults with B-cell precursor acute lymphoblastic leukemia (B-ALL) who achieve measurable residual disease (MRD)–negative complete remission nonetheless have a considerable risk for relapse. To evaluate a strategy to further improve outcomes, investigators conducted a multicenter, randomized, phase 3 trial comparing the anti-CD19/anti-CD3 T-cell–engaging bispecific antibody blinatumomab in combination with four cycles of consolidation chemotherapy versus chemotherapy alone. Eligible patients were ages 30–70 and were in MRD-negative complete remission after induction chemotherapy (<0.01% leukemic cells in bone marrow by multicolor flow cytometry); of 488 patients screened, 224 met eligibility criteria. The primary endpoint was overall survival (OS).

At a median follow-up of 43 months, a planned interim analysis showed the 3-year OS to be 85% in the blinatumomab arm versus 68% with chemotherapy alone (hazard ratio, 0.41; P<0.002). Three-year relapse-free survival was also significantly improved with blinatumomab (80% vs. 68%). Outcomes were improved with blinatumomab across all subgroups of favorable and unfavorable clinical and biomarker categories. Grade 3 or higher neurologic and psychiatric toxicities were more frequent with blinatumomab (23% vs. 5%; P<.001).