However, in intent-to-treat analyses, median progression-free survival was more than twice as long with the combination (20.1 months vs. 9.9 months; exploratory hazard ratio, 0.69).
In each treatment arm, about one-third of patients had a bone density T score below –1.5 at baseline, and about one-third received bisphosphonates during the study. But, by the end of the study, the proportion of patients with a T score below –1.5 was smaller in those on combination therapy (14% vs. 32%).
"There were no unexpected toxicities associated with dasatinib," Dr. Paul commented. The addition of this agent was associated with higher rates of grade 3 rash, edema, fatigue, anemia, neutropenia, arthralgia, and pleural effusion, but there were no grade 4 toxicities. Overall, one-quarter of patients needed a dasatinib dose reduction.
Dr. Paul disclosed no relevant conflicts of interest. The trial was sponsored by Bristol-Myers Squibb, the makers of SPRYCEL (dasatinib).