Posted: Wednesday, April 21, 2021
Alan K. Burnett, MD, of Cardiff University School of Medicine, United Kingdom, and colleagues conducted a study to determine the optimal number of treatment courses for younger patients with acute myeloid leukemia (AML). This trial discovered that although four courses of high-dose cytarabine improved relapse-free survival, there was not a significant overall survival benefit when compared with three courses. These findings were published in the Journal of Clinical Oncology.
“In general, patients with more favorable characteristics appear to benefit from a fourth course, but only when high-dose [cytarabine] consolidation is used, whereas those with intermediate-risk characteristics do not, although these were only trends for benefit,” the researchers concluded. “Overall, this experience suggests that if [cytarabine] is the chosen consolidation treatment, a fourth course of overall treatment is probably beneficial.”
The AML17 trial enrolled 1,709 patients (aged 18 to 60) with AML to receive two induction courses of daunorubicin and cytarabine, supplemented with gemtuzumab ozogamicin. After recovery, 1,017 patients were randomly assigned to receive a third course of amsacrine, cytarabine, and etoposide, plus a fourth course of mitoxantrone and cytarabine.
At 5 years, patients who received a fourth course of treatment had a lower cumulative incidence of relapse compared with three-course recipients (50% vs. 58%: hazard ratio [HR] = 0.81 [0.69–0.97], P = .02). The overall survival was not significantly improved (63% vs. 57%: HR 0.84 [0.69–1.03], P = .09), which suggested that neither course amount was superior to the other. However, a fourth course seemed to be beneficial in regard to relapse alone when the regimen was cytarabine.
Although measurable residual disease (MRD) status impacted survival, a fourth course did not seem to have an effect in either MRD-negative or MRD-positive patients. Additionally, the fourth course appeared to be beneficial in patients who lacked a FLT3 or NPM1 mutation, had fewer than three gene mutations, or had a white blood cell count of less than 10 × 109/L.
Disclosure: For full disclosures of the study authors, visit ascopubs.org.