Long-term follow-up of three randomized trials comparing idarubicin and daunorubicin as induction therapies for patients with untreated acute myeloid leukemia.

Overview

BACKGROUND: Most clinical trials for acute leukemia have reported results after 2-3 years of follow-up. Comparisons between the original data and longer-term follow-up data may be of interest, particularly with regard to promising new therapies. METHODS: In 1996, survival data were updated from three prospective, randomized comparisons of idarubicin and daunorubicin that began in 1984 and 1985. These were trials of the Memorial Sloan-Kettering Cancer Center (MSKCC), the U.S. Multicenter Study Group, and the Southeastern Cancer Study Group (SEG). The original results of these trials were reported in 1991 and 1992. RESULTS: The original results of the SEG trial demonstrated no significant difference between idarubicin and daunorubicin. The updated survival analysis showed similar results. The MSKCC trial revealed a significant advantage of idarubicin compared with daunorubicin in both the original and the updated analyses. The U.S. Multicenter trial found a significant difference favoring idarubicin in the original analysis, but the difference was not significant in the updated analysis. CONCLUSIONS: It is essential that the median length of follow-up be clearly stated in any clinical trial. When the results obtained with a particularly promising new drug or procedure are presented early in the course of study (within 1-2 years), the investigators should strongly consider a repeat evaluation after an additional 3-5 years of follow-up.