The US Food and Drug Administration (FDA) has granted approval for the use of dasatinib (Sprycel) in pediatric patients with Philadelphia chromosome–positive (Ph+) chronic myeloid leukemia (CML) in the chronic phase. The approval comes after a priority review and orphan drug designation for dasatinib.
“While CML is rare in children, accounting for less than 3% of all pediatric leukemias, it is often more aggressive in younger patients than in adults and until recently, there have been few available treatment options,” said Vickie Buenger, president of the Coalition Against Childhood Cancer, in a press release from dasatinib’s developer Bristol-Myers Squibb.
Dasatinib was approved in 2006 for treatment of Ph+ CML in adult patients who are resistant or intolerant to prior therapies including imatinib; it also received approval for treatment of Ph+ acute lymphoblastic leukemia. A few years later, in 2010, the agent was approved for adult patients with newly diagnosed Ph+ CML in the chronic phase.
The new approval for use in children was based on results of a phase I and a phase II trial, totaling 97 patients. Of those, 46 patients (17 in the phase I trial and 29 in the phase II trial) were resistant or intolerant to imatinib, and 51 patients were newly diagnosed with CML.
After 24 months, almost all the newly diagnosed patients (96.1%) had a complete cytogenetic response (CCyR); most of the resistant/intolerant patients also had a CCyR (82.6%). After a median follow-up of 4.5 years in the newly diagnosed patients and of 5.2 years in the resistant/intolerant patients, the median duration of response for both groups had not yet been reached.
A major molecular response at 24 months was achieved in 74.5% of newly diagnosed patients, and in 52.2% of those who had received prior imatinib.
The most common adverse events seen with dasatinib included headache, nausea, diarrhea, skin rash, vomiting, pain in extremity, abdominal pain, fatigue, and arthralgia.
“Options for pediatric patients with CML are limited, and it is challenging to conduct clinical trials investigating potential new treatments in this small patient population,” said Lia Gore, MD, of the University of Colorado School of Medicine. “Dasatinib is an important new option to help address the unmet needs of children with Ph+ CML in chronic phase.”