AALL1331 — Effect of Postreinduction Therapy Consolidation With Blinatumomab vs Chemotherapy on Disease-Free Survival in Children, Adolescents, and Young Adults With First Relapse of B-Cell Acute Lymphoblastic Leukemia

Phase III · 2021 · Acute Lymphoblastic Leukemia

Design

Randomized phase III trial in children, adolescents, and young adults with high- or intermediate-risk first relapse of B-cell ALL, comparing two cycles of blinatumomab versus intensive multiagent chemotherapy as post-reinduction consolidation before hematopoietic stem cell transplant. A separate low-risk relapse cohort was reported separately (JCO 2023).

Population

208 patients (median age 9 years) with high- or intermediate-risk first relapse of B-cell acute lymphoblastic leukemia.

Primary Endpoint

Disease-free survival

Key Result

With 2.9 years median follow-up, 2-year disease-free survival was 54.4% with blinatumomab versus 39.0% with chemotherapy (HR 0.70; 95% CI 0.47-1.03; 1-sided P=.03), and 2-year overall survival was 71.3% versus 58.4% (HR 0.62; 95% CI 0.39-0.98; 1-sided P=.02). Although the disease-free survival stopping boundary was not formally met, blinatumomab produced higher MRD clearance and markedly lower serious toxicity, prompting early closure of randomization for loss of clinical equipoise.

Guideline Impact

Supports blinatumomab consolidation before transplant in first-relapse B-ALL