ORLANDO – Age did not affect molecular response or the incidence of adverse reactions to nilotinib among patients with chronic myeloid leukemia in chronic phase (CML-CP), based on results from a subanalysis of the ENEST1st study.
The analysis of the ENEST1st study, reported by Dr. Francis J. Giles, compared outcomes for 1,089 newly diagnosed CML-CP patients, 19% were aged 65 years or older and 81% were younger than age 65 years. All patients had typical transcripts and were treated for 3 months or less with nilotinib 300 mg twice daily in the open-label study.
Dr. Francis J. Giles
For those 65 years and older, Sokal risk scores were low in 4.5%, intermediate in 61.2%, and high in 23.4%, with missing data for 10.9%. For younger patients, Sokal risk scores were low in 42.1%, intermediate in 32%, and high in 16.9%, with missing data for 9.
At 18 months, there was an overall 38.4% rate (95% CI, 35.5%-41.3%) of MR4 grade molecular response, which was defined as BCR-ABL level of 0.01% or less on the International Scale or undetectable BCR-ABL in cDNA with at least 10,000 ABL transcripts.
The MR4 rate at 18 months did not significantly vary by age. For patients under age 65, the cumulative incidence of MR4 by 18 months was 48.8% (95% CI, 45.4% - 52.1%); among patients aged 65 and older, the incidence of MR4 was 48.3% (95% CI, 41.4% - 55.2%). The MR4.5 rate by 18 months was 32.5% in younger patients and 28.4% in older patients, reported Dr. Giles of the Institute for Drug Development, Cancer Therapy and Research Center, at the University of Texas Health Science Center at San Antonio, and his colleagues.
Based on Sokal score, the MR4 rate by 18 months in younger patients was 53.6% (low), 45.2% (intermediate), and 35.4% (high), respectively. For older patients, the MR4 rate by 18 months based on Sokal score was 44.4% (low), 49.6% (intermediate), and 44.7% (high).
Six patients (0.6%) progressed to accelerated phase/blast crisis (AP/BC) on study; 13 patients (1.2%) died by 24 months. The most common adverse events were rash (21.4%), pruritus (16.5%), and headache (15.2%).
Novartis is the sponsor of the ENEST1st study. Dr. Giles consults for and receives honoraria and research funding from Novartis.
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