The U.S. Food and Drug Administration expanded the indication of the tyrosine kinase inhibitor dasatinib to include pediatric patients with Philadelphia chromosome–positive (Ph+) chronic-phase chronic myeloid leukemia (CP-CML). The drug was previously approved to treat adults with Ph+ CP-CML.
The decision was based on the results of two studies (one open-label, non-randomized, dose-ranging trial and one open-label, non-randomized, single-arm trial) of 97 pediatric patients with Ph+ CP-CML. In those trials, 51 patients (from the single-arm trial) were newly diagnosed with CP-CML, and 46 patients (17 from the dose-ranging trial and 29 from the single-arm trial) were imatinib resistant or intolerant.
Ninety-one patients were treated with dasatinib 60 mg/m2 once-daily. After a median follow-up of 4.5 years (range not provided) in newly diagnosed patients and 5.2 years (range not provided) in imatinib-resistant or -intolerant patients, the median duration of response (including the efficacy endpoints complete cytogenetic response [CCyR], major cytogenetic response [MCyR], and major molecular response [MMR]) could not be estimated.
Among the newly diagnosed cohort, the range response duration was 2.5 to 66.5 months for CCyR, 1.4 to 66.5 months for MCyR, 5.4 to 72.5 months for patients who achieved MMR by month 24, and 0.03 to 72.5 months for those who achieved MMR at any time. Among the imatinib-resistant or -intolerant group, durations of response ranged between 2.4 to 86.9 months for CCyR, 2.4 to 86.9 months for MCyR, and 2.6 to 73.6 months for MMR.
AEs were reported in 14.4 percent of patients, the most common (occurring in more than 15% of patients) of which included myelosuppression, headache, nausea, diarrhea, skin rash, and pain in the abdomen and extremities.
Source: U.S. Food and Drug Administration news release, November 9, 2017.