Dasatinib 100 mg Once Daily Best for Resistant CML

• ORLANDO—Once-daily dosing with dasatinib (Sprycel) 100 mg gives similar cytogenetic responses with considerably fewer hematologic adverse events than three other dasatinib dosing schedules in patients with chronic mye-logenous leukemia (CML) who are resistant to or intolerant of imatinib (Gleevec), according to a phase III randomized trial. Andreas Hochhaus, MD, of the University of Heidelberg, Mannheim, presented the data at the American Society of Hematology Annual Meeting (abstract 166).

The open-label, multicenter trial evaluated four dasatinib dosing schedules —50 mg or 70 mg twice daily, and 100 mg or 140 mg once daily—in 662 patients. Complete hematologic responses were achieved in 87% to 93% of patients, and were similar across all treatment arms. Major cytogenetic responses were seen in 54% to 59% of patients and complete cytogenetic responses in 42% to 45%, similar in all arms. Duration of cytogenetic responses and progression-free survival were also similar in all arms.

Compared to patients in the other three arms, patients on dasatinib 100 mg once daily had a lower incidence of grade 3-4 hematologic toxicities, including thrombocytopenia (P = .001), anemia (P = .032), neutropenia (P = .035), and leukopenia (trend, P = .079). They also had a considerably lower incidence of pleural effusions (P = .028).

Dr. Hochhaus concluded that dasatinib is better tolerated at 100 mg once daily: "I recommend using this once-daily schedule for new imatinib-resistant chronic-phase CML patients, but patients tolerating the previous schedules should continue the original treatment."