Early response to dasatinib predicted better long-term survival in adults with chronic phase chronic myeloid leukemia who had failed imatinib treatment, investigators reported online Feb. 25 in Blood.
Dr. Neil P. Shah of the University of California, San Francisco, Helen Diller Family Comprehensive Cancer Center, and his associates followed 670 patients with chronic phase chronic myeloid leukemia from a phase III randomized dose-optimization study of dasatinib. Patients were resistant to or could not tolerate imatinib.
Patients received dasatinib at 100 mg daily, 140 mg daily, 50 mg b.i.d., or 70 mg b.i.d (Blood 2014 [doi: 10.1182/blood-2013-10-532341]).
At 6 years, the 100-mg group had an overall survival of 71% and a progression-free survival of 49.3%, with the lowest rates of discontinuation because of toxicity.
A BCR-ABL transcript level of 10% or less at 3 months was a "particularly strong predictor" of survival, researchers reported.
Patients who achieved this level had 6-year progression-free survival rates of 58% to 68%, compared with 26% for other patients.
A major cytogenetic response at 3 and 6 months also predicted better progression-free and overall survival.
Dr. Shah and nine of his associates reported receiving support from or serving as consultants to Bristol-Myers Squibb, who funded the study, and three other associates reported being employees of Bristol-Myers Squibb.