Mitoxantrone increased survival in children with relapsed acute lymphobastic leukemia (ALL) so significantly in a recent study that randomization to that agent or idarubicin was eventually stopped.
Survival rates for youths with ALL have improved greatly over the past 20 years, but the outcome of those who relapse remains largely unchanged, noted an investigative team led by Catriona Parker, PhD, a cancer researcher at the University of Manchester in the United Kingdom, in an online report for The Lancet. In order to explore the outcome of children with ALL who had relapsed on current therapeutic regimens, Dr. Parker’s group launched an open-label, randomized trial across 31 facilities in the United Kingdom, Ireland, Australia, and New Zealand. Patients aged 1 to 18 years experiencing their first ALL relapse were divided into high-risk, intermediate-risk, and standard-risk groups based on duration of first complete remission, site of relapse, and immunophenotype. The 216 subjects were randomized to mitoxantrone or idarubicin, and all high-risk children received an allogenic stem-cell transplant as well.
Three-year overall survival was 69% in the mitoxantrone group, compared with 45.2%, for the idarubicin users. Estimated 3-year progression-free survival was 64.6% and 35.9%, respectively, with that difference mainly related to a reduction in disease events (progression, second relapse, and disease-related deaths) rather than an increase in adverse treatment effects (second malignancy, treatment death).
The authors contend that these results—which were also presented last week at the annual meeting of the American Society of Hematology, December 4-7, 2010 (www.hematology.org/Meetings/Annual-Meeting/)—warrant further investigation.