Real-World Evaluation of Treatment Patterns and Clinical Outcomes among Patients With Chronic Myeloid Leukemia in Chronic Phase Treated With Asciminib in Clinical Practice in the United States

Background

Tyrosine kinase inhibitors (TKIs) are the mainstay treatment for chronic myeloid leukemia in chronic phase (CML-CP). Asciminib, an ABL/BCR::ABL1 inhibitor which binds to the myristoyl pocket, was recently approved in the US for patients with CML-CP previously treated with ≥2 TKIs or with the T315I mutation. This study described treatment patterns and real-world clinical outcomes among patients with CML-CP treated with asciminib in US clinical practice.

Methods

Electronic health record data from adult patients with CML-CP who initiated asciminib after ≥2 prior TKIs, without the T315I mutation, were obtained from the Flatiron Health database. Time-to-treatment discontinuation and molecular response (MR; time-to-BCR::ABL ≤0.1% and time-to-BCR::ABL1 ≤1%, separately) were evaluated from asciminib initiation (index date) using Kaplan–Meier analyses.

Results

Overall, 97 patients initiated asciminib (median age: 63 years, 50.5% female, 64.9% White) after either 2 (47.4%) or 3 (24.7%), or ≥4 (27.8%) prior TKIs. In total, 85.7% and 78.1% of patients remained on asciminib by 12- and 24-weeks postindex, respectively. Among patients with ≥1 MR assessment postindex, 31.3% (95% confidence interval [CI]: 21.6%, 43.9%) and 49.7% (95% CI: 38.1%, 62.6%) achieved or maintained BCR::ABL1 ≤0.1%, while 51.3% (95% CI: 40.1%, 63.6%) and 64.2% (95% CI: 52.6%, 75.6%) achieved or maintained BCR::ABL1 ≤1%, by 12- and 24-weeks, respectively.

Conclusions

Results of this real-world study describing clinical outcomes among patients with CML-CP treated with asciminib after ≥2 prior TKIs in the US demonstrated that asciminib was well-tolerated and effective. These findings were consistent with results from the ASCEMBL trial.