Recent CML Advances Reshape Frontline Treatment and TKI Sequencing

Key Clinical Summary:  

• Treatment selection for chronic myeloid leukemia in chronic phase (CML-CP) increasingly considers treatment goals, disease risk, comorbidities, toxicity, and cost rather than molecular response rates alone.
• The review supports dose reduction for patients with positive molecular responses who develop nonprohibitive tyrosine kinase inhibitor (TKI) toxicities, reserving treatment switches for prohibitive adverse events or resistance.
• Asciminib has produced higher major molecular response rates than investigator-selected TKIs in newly diagnosed CML-CP, while emerging kinase-domain and STAMP inhibitors could further expand options after treatment failure. 

Advances in BCR::ABL1-targeted therapy are expanding treatment options for CML-CP while challenging several long-standing approaches to TKI dosing, toxicity management, and treatment sequencing, according to a recent research review.

The authors emphasized that contemporary CML management should balance survival, the possibility of treatment-free remission (TFR), safety, comorbidities, disease risk, and treatment cost. Although increasingly potent therapies can produce faster and deeper molecular responses, those advantages do not necessarily translate into improved overall survival.

Molecular Response Goals Shape Treatment Decisions

Achieving a complete cytogenetic response, corresponding to BCR::ABL1 transcripts of less than 1% on the International Scale, within the first year of TKI therapy is associated with survival approaching that of an age-matched population.

Major molecular response, defined as BCR::ABL1 of less than 0.1%, is associated with improved event-free survival. However, the authors noted that achieving major molecular response has not demonstrated an overall survival advantage compared with not achieving it.

Deeper responses may become particularly important when TFR is a treatment goal. Sustained deep molecular response, defined as BCR::ABL1 of less than 0.01%, for at least 2 years has been associated with successful TKI discontinuation and TFR in approximately 35% to 45% of patients. With deep molecular response sustained for at least 5 years, the review cited a TFR rate of approximately 80%.

Frontline Therapy Requires Individualized Selection

Five agents are currently used as frontline therapy: imatinib, dasatinib, bosutinib, nilotinib, and asciminib, the latter representing the first approved Specifically Targeting the ABL Myristoyl Pocket (STAMP) inhibitor.

The authors argued that generic imatinib remains an important frontline option when normalization of survival, safety, and value are primary considerations. When earlier deep molecular response and eventual TFR are higher priorities, or for patients with higher-risk CML, a more potent therapy may be considered.

Cost represents an increasingly important distinction. The review cited US treatment costs of less than $500 annually for generic imatinib and approximately $1600 annually for dasatinib at 50 mg daily, compared with at least $300 000 annually for asciminib.

The authors therefore questioned whether improvements in molecular response alone are sufficient to justify large cost differences when survival advantages have not been demonstrated.

Asciminib Produces Higher Molecular Response Rates

The phase 3 ASC4FIRST trial has strengthened the evidence supporting asciminib in newly diagnosed CML-CP.

At approximately 2.2 years of follow-up, major molecular response was achieved in 74.1% of patients receiving asciminib compared with 52.0% receiving investigator-selected TKIs. Among patients compared with second-generation TKIs, corresponding rates were 72.0% and 56.9%.

Although these findings demonstrate improved molecular efficacy, the review cautioned that higher major molecular response rates have not yet been shown to improve survival or increase TFR rates. Longer-term follow-up will therefore be important in defining the clinical value of frontline asciminib.

Lower TKI Doses May Preserve Efficacy While Reducing Toxicity

The review also challenges the historical practice of switching TKIs whenever toxicity develops.

For patients who have achieved a good molecular response but develop nonprohibitive adverse events, the authors recommend reducing the dose of the existing TKI rather than automatically changing therapies. A switch should generally be reserved for prohibitive toxicity.

This approach reflects increasing evidence that an optimal biologic dose may provide efficacy comparable to the US Food and Drug Administration–approved dose while improving tolerability.

Such strategies could have implications for adherence, quality of life, and resource utilization, particularly because many patients require years or decades of treatment.

New Options Expand Treatment After Resistance

Patients with resistance or intolerance to frontline therapy now have multiple subsequent treatment options, including second-generation TKIs, ponatinib, and asciminib.

The pipeline could expand these choices further. Investigational ABL1 kinase-domain inhibitors include olverembatinib and ELVN-001, while TERN-701 and TGRX-678 are investigational STAMP inhibitors.

The authors use BCR::ABL1 transcripts greater than 1% after 1 year of therapy as a practical definition of TKI resistance, emphasizing the importance of identifying resistance and selecting subsequent therapy based on prior treatment, mutations, toxicity, and patient characteristics.

Implications for Managed Care

The expanding CML treatment landscape presents managed care decision-makers with a growing tension between molecular efficacy and treatment value. Generic TKIs can provide long-term disease control at substantially lower costs, while newer agents may offer faster or deeper responses and different toxicity profiles.

Treatment goals may therefore be central to determining value. For a patient primarily seeking long-term survival with manageable toxicity, a low-cost generic TKI may remain appropriate. For patients prioritizing a deep molecular response and potential future TFR, the value proposition of a more potent therapy may differ.

Dose optimization may provide another opportunity to improve value by reducing adverse events without sacrificing disease control. As additional targeted agents enter clinical development, incorporating efficacy, tolerability, resistance profiles, treatment goals, and costs into individualized treatment algorithms will become increasingly important.

Conclusion

Recent advances in CML-CP are shifting treatment toward a more individualized strategy that considers not only molecular response but also toxicity, TFR goals, comorbidities, and cost. The review supports greater use of dose optimization and highlights asciminib and emerging targeted agents as important components of an increasingly diverse treatment landscape.

References

Haddad FG, Kantarjian H. Chronic myeloid leukemia: incorporation of recent advances into current treatment algorithms. Blood Cancer J. 2026;(16)123. doi:10.1038/s41408-026-01527-6