Ponatinib More Effective Than Imatinib in Newly Diagnosed Ph+ ALL

Ponatinib was more effective than imatinib when given with reduced-intensity chemotherapy in patients with newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL), according to results from the phase III PhALLCON trial.

The phase III PhALLCON trial is the first head-to-head comparison of first-line treatment with ponatinib compared to imatinib in combination with chemotherapy in these patients.

In the open-label trial, 245 adult patients were randomized 2:1 to receive either ponatinib or imatinib along with reduced-intensity chemotherapy. At data cutoff, 78 patients (41% ponatinib and 12% imatinib) were still receiving treatment. The top reasons for treatment discontinuation were hematopoietic stem cell transplantation (30% ponatinib vs 37% imatinib), adverse events (12% vs 12%), and lack of efficacy (7% vs 26%).

The primary endpoint of measurable residual disease negativity complete remission after a 12-week induction period was significantly higher in the ponatinib group than the imatinib group (34.4% vs 16.7%; P=.0021). Event-free survival was reached in the imatinib group but not in the ponatinib group, with a trend toward improvement in the experimental arm of the trial. Adverse events and arterial occlusive events were similar between the treatment groups.

“The potential benefit to patients who achieve this early deep response may be important to improve long-term survival outcomes,” said lead author Elias Jabbour, MD, from the University of Texas MD Anderson Cancer Center. “The trial results indicate ponatinib as a potential standard of care for patients newly diagnosed with Ph+ ALL.”

Funding was provided by Takeda Development Center Americas, Inc.

Source: ASCO press release, February 2023