AALL0331 — Standard-Risk B-Precursor Acute Lymphoblastic Leukemia (ALL): A Groupwide Phase III Study of Risk-Directed Therapy (Children's Oncology Group AALL0331)

Phase III · 2019 · Acute Lymphoblastic Leukemia

Design

Multicenter phase III trial that used clinical features and minimal residual disease to stratify children with National Cancer Institute standard-risk B-ALL, then randomized subgroups to standard versus intensified post-induction therapy.

Population

Children aged 1 to 9 years with newly diagnosed NCI standard-risk B-cell acute lymphoblastic leukemia (white blood cell count < 50,000/μL).

Primary Endpoint

Continuous complete remission / event-free survival

Key Result

Standard-risk average patients had excellent outcomes with 6-year continuous complete remission of ~90.8%-91.6% and 6-year overall survival ~97% with no benefit from intensified consolidation (P = .99), while standard-risk high patients benefited from augmented BFM therapy.

Guideline Impact

Established MRD-directed risk stratification as standard for pediatric standard-risk B-ALL