At different key milestones throughout the study, the CCgR rate was high (78 percent at three months, 96 percent at six, 12, and 18 months). Within 12 months, the cumulative CCgR rate for study participants was 100 percent, which means that all patients achieved CCgR at least once. Additionally, after a median follow-up of 36 months, overall survival, progression-free survival, and failure-free survival reached 99 percent for each, and event-free survival was 92 percent. The cumulative major molecular response (MMR) rate, a more sensitive measurement of response, was 96 percent at 12 months. The MMR rate was 52 percent at three months, 66 percent at six months, 85 percent at one year, 81 percent at 18 months, and 82 percent at two years. In patients who achieved an MMR, none progressed to accelerated or blast phase CML. Furthermore, only one patient in the entire study progressed to accelerated or blast phase due to the development of another BCR-ABL mutation called a T315I mutation.

"While it is important to rapidly induce responses in these patients, it is also important that these responses last as long as possible," said lead study author Gianantonio Rosti, MD, Scientific Secretary of the GIMEMA CML WP, Department of Hematology and Oncology, University of Bologna, Bologna, Italy. "Results from this study not only show that nilotinib quickly induces high rates of response, but responses also are durable and stable beyond three years, translating into optimal outcomes for newly diagnosed patients with Philadelphia chromosome-positive chronic myeloid leukemia."

Dr. Rosti will present this study in an oral presentation on Monday, December 6, at 10:30 a.m. in Room Valencia D.

A Phase I Trial of Oral Ponatinib (AP24534) in Patients With Refractory Chronic Myelogenous Leukemia (CML) and O
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