The tyrosine kinase inhibitor ponatinib and monoclonal antibody blinatumomab — which targets CD19 on leukaemia cells — are highly effective as monotherapies for patients with Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukaemia (ALL).

The combination may provide an alternative to chemotherapy and stem cell transplant (SCT) without the associated risks and side effects.

In a Phase II trial presented by Nicholas Short, M.D., researchers evaluated the safety and efficacy of the chemotherapy-free combination of ponatinib plus blinatumomab in 55 patients with either newly diagnosed (ND) or relapsed/refractory (R/R) Ph+ ALL and patients with chronic myeloid leukaemia in lymphoid blast phase (CML-LBP).

Complete molecular response was seen in 96% of ND patients, 92% of R/R patients and 83% of CML-LBP patients.

For ND patients, the two-year event-free survival (EFS) rate and overall survival (OS) rate each were 93%. No relapses have been observed, and SCT was not needed in first remission.

The treatment was well-tolerated, suggesting this combination is safe and effective for patients with Ph+ ALL. The promising outcomes in ND patients with Ph+ ALL suggest that this regimen may be able to eliminate the need for chemotherapy and SCT for these patients.

Source: The University of Texas MD Anderson Cancer Center