Quality-Adjusted Time Without Symptoms of Disease or Toxicity (Q-TWiST) in Patients With Newly Diagnosed Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia: A Comparison of Ponatinib Versus Imatinib.

BACKGROUND

In the phase 3 ponatinib-3001 trial (PhALLCON, NCT03589326), ponatinib demonstrated superior efficacy over imatinib with comparable safety in patients with newly diagnosed Philadelphia-positive acute lymphoblastic leukemia (Ph+ ALL). This post hoc analysis evaluated the net benefits of ponatinib using a quality-adjusted time without symptoms of disease or toxicity (Q-TWiST) approach.

METHODS

Overall survival (OS) time for patients from PhALLCON was partitioned into three health states: TOX (time with grade 3+ treatment-emergent adverse events [TEAEs] before disease progression), TWiST (time without toxicity before progression), and REL (time from progression until death or end of follow-up). Q-TWiST was calculated as the sum of health utility-weighted restricted mean durations of the three states. A relative Q-TWiST gain of ≥ 10% was considered clinically important. Sensitivity analyses were conducted by varying TOX and REL utilities, follow-up time, and the TOX definition (using grade 2+ TEAEs or patient-perceived treatment tolerability assessed by the FACT-GP5).

RESULTS

Among all randomized patients (ponatinib n = 164, imatinib n = 81), restricted mean OS was similar between arms (1082.2 vs. 1024.8 days; p = 0.373). In the base-case analysis, mean TWiST was 214.5 days longer with ponatinib versus imatinib (95% CI 70.3-358.7; p = 0.004), REL was shorter by 175.9 days (325.4-26.5; p = 0.021), and TOX was not significantly different between arms (p = 0.228). The relative Q-TWiST gain (10.98%) was clinically important. Sensitivity analyses consistently supported the robustness of the base-case findings.

CONCLUSION

Ponatinib may prolong quality-adjusted survival compared with imatinib, supporting the benefit-risk profile of ponatinib as a front-line treatment for Ph+ ALL.

TRIAL REGISTRATION: NCT03589326.