Induction Therapy and Hematopoietic Stem Cell Transplantation for Mixed-Phenotype Acute Leukemia

A recent analysis of treatment options for patients with mixed-phenotype acute leukemia (MPAL) suggests favorable outcomes may be obtained with frontline therapy using a chemotherapy regimen usually administered to patients with acute lymphoblastic leukemia (ALL) and without hematopoietic stem cell transplantation (HSCT). Results of this analysis were published in Cancer.

In this central review of MPAL outcomes, the Children’s Oncology Group Acute Leukemia of Ambiguous Lineage Task Force studied a cohort of 54 patients aged 1 to 30 years with diagnoses of MPAL who were enrolled in clinical trials involving ALL or acute myeloid leukemia (AML) treatments.

Induction therapies typically consisted of ALL treatment regimens, AML treatment regimens, or a hybrid of both approaches. A variety of postinduction treatment options, with or without HSCT, were also included.

Patients with MPAL who were given ALL (72%) or AML (24%) induction treatments did not significantly differ from each other in reported baseline characteristics.

End-of-induction complete remission was achieved by 72% of patients treated with an ALL induction regimen and by 69% of patient given an AML induction regimen.

Among all patients in the cohort, the 5-year overall survival rate was 77%; among patients who received ALL chemotherapy without HSCT, the 5-year overall survival rate was 84%. The 5-year event-free survival rate was 72% for the total cohort and 75% among those who received ALL chemotherapy without HSCT.

The researchers stated that their findings “demonstrated that durable remissions are possible for a subset of patients with MPAL receiving ALL chemotherapy without HSCT consolidation.” They also described a forthcoming prospective clinical trial that will test a minimum residual disease-guided treatment approach with ALL therapy and without HSCT in patients with MPAL.

Reference

1. Orgel E, Alexander TB, Wood BL, et al. Mixed-phenotype acute leukemia: A cohort and consensus research strategy from the Children’s Oncology Group Acute Leukemia of Ambiguous Lineage Task Force [published online October 29, 2019]. Cancer. doi:10.1002/cncr.32552

This article originally appeared on Hematology Advisor