(Complete cytogenetic response is the absence of the defective chromosome that causes the disease. Major molecular response is defined as a level of .1 percent or lower of the BCR-ABL oncoprotein as measured by a more sensitive test than traditional cytogenetic analysis.)
Dasatinib vs. Imatinib
In the Dasatinib versus Imatinib Study In Treatment-nave CML Patients (DASISION) trial, 519 previously untreated CML patients were randomized to either 100 mg of dasatinib once a day or 400 mg of imatinib once a day.
In the dasatinib arm, 77 percent of patients achieved a confirmed complete cytogenetic response (CCyR), 46 percent reached major molecular response (MMR) and 1.9 percent had their CML progress.
Of those receiving imatinib, 66 percent reached complete cytogenetic response, 28 percent major molecular response, and 3.5 percent had their disease progress.
Responses were faster with dasatinib, with 54 percent at CCyR at 3 months and 73 percent at six months compared with 31 percent and 59 percent for imatinib.
Side effects for dasatinib and imatinib were mostly low-grade. Hematologic side effects were slightly more common on dasatinib, while other low-grade side effects such as nausea, vomiting, muscle pain and inflammation were higher on imatinib.
Nilotinib vs. Imatinib
In the Evaluating Nilotinib Efficacy and Safety in Clinical Trials Newly Diagnosed Patients (ENEST) trial, 836 new CML patients were randomized to either 300 mg or 400 mg of nilotinib twice daily, or to 400 mg of imatinib once a day.
Results in both nilotinib arms of the trial were nearly identical. In the 300 mg twice daily group, 80 percent of patients reached complete cytogenetic response, 44 percent achieved major molecular response and less than 1 percent had disease progression. For the higher
|Contact: Scott Merville|
University of Texas M. D. Anderson Cancer Center