Later-Generation CML Therapies May Have Limited Effect on Patient Out-of-Pocket Costs

Key Takeaways:

• A US economic analysis found that annual treatment costs for imatinib and most later-generation tyrosine kinase inhibitors (TKIs) exceeded 2025 out-of-pocket spending limits for Medicare Part D and typical commercial insurance plans.
• Because patients would generally reach their annual out-of-pocket maximum regardless of TKI selected, switching from imatinib to a later-generation therapy was projected to have little effect on insured patients’ direct costs.
• For payers, replacing imatinib with later-generation therapies increased estimated monthly premiums modestly, with an all-payer budget impact ranging from $0.76 to $4.23 per member per month.

Changes to US prescription drug benefit design may substantially reduce differences in what insured patients with chronic myeloid leukemia (CML) pay for imatinib compared with newer TKIs, despite large differences in drug acquisition costs, according to a recent economic analysis.

Investigators modeled the financial impact of asciminib, bosutinib, dasatinib, nilotinib, and ponatinib compared with imatinib from both patient and payer perspectives, including changes associated with implementation of the Inflation Reduction Act in 2025.

Drug Costs Exceeded Annual Out-of-Pocket Limits

The analysis estimated per-patient, per-year treatment costs using US Food and Drug Administration label–based dosing and wholesale acquisition costs.

In 2025, the weighted annual cost of branded and generic imatinib was estimated at $22 430. Annual costs for most later-generation TKIs exceeded $100 000, although estimated costs were lower for dasatinib at $72 693 and nilotinib at $89 138.

Despite these large differences in acquisition cost, investigators found that imatinib and the later-generation agents generally exceeded annual out-of-pocket limits under Medicare Part D, an average commercial insurance plan, and a commercial plan with the highest allowable annual out-of-pocket limit.

As a result, switching from imatinib to a later-generation TKI was projected to produce little or no additional annual out-of-pocket burden for most insured patients.

The effect was particularly relevant for Medicare beneficiaries following implementation of the Inflation Reduction Act, which established a $2 000 annual out-of-pocket cap for Medicare Part D prescription drugs beginning in 2025.

Payer Budget Impact Remained Relatively Modest

Investigators also modeled the financial consequences for an all-payer US health plan with 1 million members.

Such a plan was estimated to include approximately 200 patients with Philadelphia chromosome–positive CML eligible for TKI therapy. Switching patients from imatinib to a later-generation TKI increased the estimated budget impact by $0.76 to $4.23 per member per month.

The projected impact varied by payer. Monthly premium increases associated with later-generation TKIs ranged from $2.20 to $12.27 among Medicare beneficiaries, compared with $0.58 to $3.26 for Medicaid and $0.58 to $3.22 for commercially insured populations.

Generic availability reduced the payer impact considerably. Compared with imatinib, the per-member-per-month difference was $0.42 for generic dasatinib and $0.54 for generic nilotinib, substantially lower than estimates for their branded equivalents.

Sensitivity analyses varying imatinib pricing, later-generation TKI costs, and generic uptake produced an all-payer budget impact ranging from $0.42 to $5.15 per member per month.

Implications for Managed Care

The findings suggest that the choice of CML therapy may be increasingly disconnected from patients’ direct financial exposure, particularly among Medicare beneficiaries subject to annual out-of-pocket caps.

For clinicians, this could provide greater flexibility to select a TKI based on efficacy, safety, tolerability, treatment goals, and patient characteristics without assuming that a more expensive agent will necessarily result in higher annual patient spending.

For health plans, however, higher acquisition costs are largely shifted to the payer. The authors noted that the overall premium effect may remain limited because CML is relatively uncommon, although plan design, formulary placement, deductibles, rebates, manufacturer assistance, and negotiated discounts could meaningfully alter the financial experience of individual patients and insurers.

The analysis was based on modeled costs rather than real-world claims and assumed wholesale acquisition costs without incorporating payer rebates or manufacturer discounts. The authors therefore called for future analyses using actual patient cost-sharing and net drug price data.

Conclusion

Under 2025 US insurance benefit structures, both imatinib and later-generation TKIs were projected to exceed annual out-of-pocket limits for many insured patients with CML, minimizing differences in direct patient spending. Although newer TKIs increased payer expenditures, their modeled effect on health plan premiums remained relatively modest.

Reference

Vaughn JE, Zawadzki N, Zhang S, Pinkston P, Wei D, & Shafrin J. Financial impact of treatment choice in chronic myeloid leukemia: a comparison of later generation TKIs versus imatinib from patient and payer perspectives. Clinicoecon Outcomes Res. 2026;18. doi:10.2147/CEOR.S626752