(HealthDay News) — Ponatinib is active in chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph-positive ALL), according to a study published online Nov. 1 in the New England Journal of Medicine.
Jorge E. Cortes, M.D., from the University of Texas MD Anderson Cancer Center in Houston, and colleagues conducted a phase 2 trial of ponatinib (45 mg once daily) in 449 heavily pretreated patients with CML or Ph-positive ALL with resistance to or unacceptable side effects from dasatinib or nilotinib, or with the BCR-ABL T315I mutation. Patients were followed for a median of 15 months.
The researchers found that of the 267 patients with chronic-phase CML, 56%, 46%, and 34%, respectively, had a major cytogenetic response, a complete cytogenetic response, and a major molecular response. Responses were durable (estimated rate of sustained major cytogenetic response of at least 12 months, 91%) and were seen regardless of the baseline BCR-ABL kinase domain mutation status.
Among 83 patients with accelerated-phase CML, 55% and 39%, respectively, had a major hematologic and major cytogenetic response, while among the 62 patients with blast phase CML, the response rates were 31% and 23%, respectively. The major hematologic and cytogenetic response rates were 41% and 47%, respectively, for those with Ph-positive ALL.
“In conclusion, ponatinib showed clinically significant activity in patients with CML and those with Ph-positive ALL,” the authors write.
Several authors disclosed financial ties to pharmaceutical companies, including Ariad Pharmaceuticals, which manufactures ponatinib and funded the study.