Asciminib Shows Durable Frontline Benefit in Newly Diagnosed CML
Key Clinical Summary
- At week 96, asciminib achieved higher major molecular response (MMR) rates than investigator-selected tyrosine kinase inhibitors (IS-TKIs) in newly diagnosed chronic myeloid leukemia in chronic phase (CML-CP).
- MMR was 74.1% with asciminib vs 52.0% with comparator tyrosine kinase inhibitors (TKIs).
- Asciminib was associated with fewer treatment discontinuations due to adverse events (AEs) than imatinib or second-generation TKIs.
Asciminib continued to show durable efficacy and a favorable tolerability profile as frontline therapy for adults with newly diagnosed CML-CP, according to the week 96 analysis of the phase 3 ASC4FIRST trial.
Study Findings
ASC4FIRST was a phase 3, multicenter, open-label, randomized trial evaluating asciminib 80 mg once daily against IS-TKIs, including imatinib, nilotinib, dasatinib, or bosutinib. The study enrolled adults diagnosed with Philadelphia chromosome–positive CML-CP within 3 months before enrollment.
A total of 405 patients were randomized. Patients were assigned to asciminib or an IS-TKI, with treatment selection stratified by the planned comparator and European Treatment and Outcome Study (ELTS) long-term survival risk category.
At week 96, asciminib achieved a MMR rate of 74.1% compared with 52.0% for all IS-TKIs. In the imatinib stratum, MMR was 76.2% with asciminib vs 47.1% with imatinib. In the second-generation TKI stratum, response was numerically higher with asciminib vs second-generation agents, at 72.0% vs 56.9%.
Deep molecular responses were also more frequent with asciminib. At week 96, MR4.5 was achieved in 30.9% of patients receiving asciminib compared with 17.7% receiving IS-TKIs.
Safety findings remained consistent with earlier results. Grade 3 or higher AEs occurred in 44.5% of patients receiving asciminib, 49.5% receiving imatinib, and 59.8% receiving second-generation TKIs. Treatment discontinuation due to AEs occurred in 5.0%, 13.1%, and 12.7%, respectively.
Clinical Implications
For US clinicians and managed care stakeholders, these findings are relevant because CML treatment often requires long-term therapy. Durable molecular response, tolerability, adherence, and quality of life are central to frontline treatment selection.
The ASC4FIRST data suggest asciminib may offer improved molecular disease control while reducing treatment disruption. Fewer dose reductions, interruptions, and discontinuations may be important for maintaining long-term therapy and limiting downstream treatment changes.
The authors noted that deeper molecular responses may support future treatment-free remission eligibility, although longer follow-up is needed to confirm durability. They concluded that asciminib offers a better benefit-risk profile than all IS-TKIs, imatinib, and second-generation TKIs in newly diagnosed CML-CP.
Conclusion
At 96 weeks, asciminib demonstrated sustained efficacy and favorable tolerability as frontline therapy for newly diagnosed CML-CP. The findings support asciminib as a potential frontline option for patients who prioritize durable response, adherence, and long-term treatment tolerability.
Reference
Cortes JE, Hughes TP, Wang J, et al. Asciminib demonstrates superior efficacy and safety in newly diagnosed chronic myeloid leukemia in the ASC4FIRST trial. Blood. 2026;147(13):1433–1446. doi:10.1182/blood.2025029210.
