Economic Burden of Tyrosine Kinase Inhibitor Treatment Failure in Chronic Myeloid Leukemia

Maximizing the Value of Chronic Myeloid Leukemia Management Using Tyrosine Kinase Inhibitors in the USA: Potential Determinants and Consequences of Healthcare Resource Utilization and Costs, with Proposed Optimization Approaches

BACKGROUND AND OBJECTIVES

The introduction and widespread use of effective and well-tolerated tyrosine kinase inhibitors for chronic myeloid leukemia have been associated with marked increments in life expectancy and disease prevalence. These changes have been accompanied by elevations in costs of tyrosine kinase inhibitors, which typically must be taken ad vitam after diagnosis and tend to be more expensive than medical therapies for many other hematologic malignancies. The aims of this review included evaluating the potential associations and consequences of healthcare resource utilization and costs of tyrosine kinase inhibitors and possible clinical management approaches to mitigate them.

METHODS

A PubMed search of English-language US study reports was conducted that covered the interval of 2001 (US approval of imatinib) through 17 April, 2023 augmented by manual reviews of published bibliographies from the referenced articles and searches of other databases: Google Scholar and Scopus.

RESULTS

On the basis of this analysis of chiefly real-world evidence (administrative claims database studies), healthcare resource utilization and costs can be considered indicators of ineffective chronic myeloid leukemia management, including potentially mutation-driven treatment resistance and costly tyrosine kinase inhibitor switches, non-adherence, and suboptimal tolerability, which may culminate in the progression of disease from the chronic to an accelerated or blast phase, with additional excess costs. Costs of tyrosine kinase inhibitors are also associated with reduced treatment adherence. At a willingness-to-pay threshold of $50,000-$200,000 per quality-adjusted life-year, tyrosine kinase inhibitors can be considered cost effective from a US payer perspective. Potential clinical approaches to mitigate costs include regular molecular monitoring with proactive assessments of BCR::ABL1 gene mutations to avoid costly treatment switches, as well as interventions to enhance treatment adherence and tyrosine kinase inhibitor tolerability.

CONCLUSIONS

Healthcare resource utilization and costs of chronic myeloid leukemia care may be considered barometers of ineffective management, including mutation-driven tyrosine kinase inhibitor resistance and switching as well as non-adherence and intolerance. Future prospective research is warranted to help determine whether costs can be reduced and other treatment outcomes optimized via more proactive and effective diagnostic interventions (i.e., regular molecular monitoring and proactive mutational testing) and treatment approaches. The strengths and limitations of this review include its emphasis on observational research, which, on one hand, offers a naturalistic "real-world" perspective on current chronic myeloid leukemia management, but, on the other hand, is associational in nature and cannot be used to determine causality and/or its direction.

Chronic Myeloid Leukemia: Part II-Cost of Care Among Patients in Advanced Phases or Later Lines of Therapy in Chronic Phase in the United States from a Commercial Perspective

Background: Tyrosine kinase inhibitors (TKIs) are the standard-of-care treatment for chronic myeloid leukemia in chronic phase (CML-CP). Despite advances in therapy, there remains a proportion of patients with CML-CP that are refractory/intolerant to TKIs, and these patients cycle through multiple lines of therapy. Moreover, even with TKIs, some patients progress to accelerated phase/blast crisis (AP/BC), which is associated with particularly poor clinical outcomes. Objectives: To describe real-world treatment patterns, healthcare resource utilization (HRU), and costs of patients with CML-CP reaching later lines of therapy or progressing to AP/BC in the United States. Methods: Adult CML patients from administrative claims data (January 1, 2000-June 30, 2019) were classified by health state: on third-line (CML-CP On Treatment), on fourth or later lines (CML-CP Post-Discontinuation), or progressed to AP/BC (CML-AP/BC). Outcomes were assessed by health state. Results: There were 296 (4620 patient-months), 83 (1644 patient-months), and 949 (25 593 patient-months) patients classified in the CML-CP On Treatment, CML-CP Post-Discontinuation, and CML-AP/BC cohorts, respectively. Second-generation TKIs (nilotinib, dasatinib, and bosutinib) were most commonly used in the CML-CP On Treatment (69.1% of patient-months) and CML-CP Post-Discontinuation cohorts (59.1% of patient-months). Three-month outpatient incidence rates (IRs) were 7.6, 8.3, and 7.0 visits in the CML-CP On Treatment, CML-CP Post-Discontinuation, and CML-AP/BC cohort, respectively, with mean costs of $597 per service. Three-month inpatient IRs were 0.6, 0.7, and 1.4 days in the CML-CP On Treatment, CML-CP Post-Discontinuation, and CML-AP/BC cohort, respectively, with mean costs of $5892 per day. Mean hematopoietic stem cell transplantation cost was $352 333; mean 3-month terminal care cost was $107 013. Discussion: Cost of CML care is substantial among patients with CML reaching third-line, fourth or later lines, or progressing to AP/BC, suggesting that the disease is associated with a significant economic and clinical burden. From third-line to fourth or later lines, HRU was observed to increase, and the incidence of inpatient days was particularly high for those who progressed to AP/BC. Conclusion: In this study, patients with CML cycling through TKIs in later lines of therapy or progressing to AP/BC experienced substantial HRU and costs, suggesting unmet treatment needs.

Expenditures for First- and Second-Generation Tyrosine Kinase Inhibitors Before and After Transition of Imatinib to Generic Status

Importance

Imatinib introduced a paradigm shift in the treatment of patients with chronic myeloid leukemia (CML), allowing a lifespan that is almost comparable to the general population. However, the health care expenditures associated with imatinib have increased steadily since its introduction in 2001. Since the generic market entry of imatinib on February 1, 2016, it became possible to determine the effect of generic entry on the health care expenditures associated with imatinib, along with the concurrent pricing trends of second-generation tyrosine kinase inhibitors (TKIs).

Objective

To compare health care expenditure related to imatinib treatment for patients with CML prior to its generic status with expenditures after, in a real-world setting.

Design, Setting, and Participants

A retrospective cohort study using data from the Truven Health MarketScan Database was carried out including 1301 commercially insured patients or patients with Medicaid between the ages of 18 and 64 years with a CML diagnosis between September 1, 2014 and December 31, 2017. A single interrupted time series (ITS) method was used to evaluate monthly expenditures associated with imatinib for the health plan from September 1, 2014 to December 31, 2017, with imatinib switching to generic on February 1, 2016, as the interruption. The initial 6-month period postinterruption was excluded to allow for the new price structure to stabilize. Nilotinib and dasatinib were evaluated using a comparative ITS design. The analysis took place between September 1, 2014 to December 31, 2017.

Main Outcomes and Measures

Commercial and Medicaid health plan expenditure and patient cost responsibility for 30-day blocks per patient for imatinib, dasatinib, and nilotinib were calculated from September 1, 2014 through December 31, 2017. Pricing was adjusted via 2017 consumer price index for medical services.

Results

The sample included a total of 1301 patients (1102 commercially insured and 199 insured through Medicaid) with a median (range) age at diagnosis of 50 (18-62) years for commercially insured patients and 50 (47-52) years for patients with Medicaid. Of the 1301 patients, 704 (54.1%) were men. There was a significant pregeneric increase in expenditure (commercially insured: $143 per patient per month, P < .001; Medicaid: $152 per patient per month, P = .001). There was a significant reduction over the 6-month interruption period (February 2016 through August 2016) between the pregeneric and generic phase (commercial: $-3097 per patient, P < .001; Medicaid: $-2077 per patient, P = .002). Controlling for secular trends, this was followed by a small decline in expenditure during the generic phase (commercially insured: -$93 per patient per month; P = .03; Medicaid: -$182 per patient per month; P = .001). Nilotinib and dasatinib maintained an increasing trend in both the pregeneric and generic phase of imatinib, resulting in a significant difference-in-difference slope for commercially insured patients (nilotinib: -$186, P = .006; dasatinib: -$175, P = .007) and patients with Medicaid (nilotinib: -$299, P = .002; dasatinib: -$329, P < .001). There were no significant trends for patient cost responsibility.

Conclusions and Relevance

The modest decline in expenditure associated with imatinib after generic entry accompanied by the increasing expenditure trends associated with the second-generation TKIs suggest a need for measures to facilitate cost reduction as well as standardization of CML treatment.

Tyrosine Kinase Inhibitors and the Relationship With Adherence, Costs, and Health Care Utilization in Commercially Insured Patients With Newly Diagnosed Chronic Myeloid Leukemia: A Retrospective Claims-Based Study

OBJECTIVE

To examine the association among tyrosine kinase inhibitor (TKI) out-of-pocket costs, adherence, and health care costs and utilization in a large group of commercially insured patients with chronic myeloid leukemia (CML).

MATERIALS AND METHODS

Patients with CML aged 18 to 64 years were identified using IBM MarketScan Commercial Database between April 1, 2011 and December 31, 2014. Patients were required to be continuously enrolled 3 months before and 12 months after TKI (imatinib, dasatinib, or nilotinib) initiation. TKI adherence is estimated using the proportion of days covered (PDC), defined as the percentage of the PDC by the prescription fill during the 12-month study period (adherent patients have PDC ≥80%). Health care cost differences between adherent and nonadherent patients were estimated using generalized linear models. Health care utilization was compared using negative binomial regression models. All models were controlled for potential confounding factors.

RESULTS

The study sample consisted of 863 patients, where 355 (41.1%) patients were classified as adherent. Over the study period, nonadherent patients incurred US$10,974 more in medical costs (P<0.001), and US$1663 more in non-TKI pharmacy costs (P<0.01). Adherent patients incurred US$28,184 more in TKI pharmacy costs (P<0.001) that resulted in US$18,305 more in overall total health care costs (P<0.001). Adherent patients, however, were estimated to be less likely to have all-cause hospitalizations (incidence rate ratio, 0.32; P<0.001), or CML-specific hospitalizations (incidence rate ratio, 0.31; P<0.01).

CONCLUSIONS

Patients with CML with better adherence experienced fewer hospitalizations, resulting in medical service cost savings. These lower medical costs, however, were more than offset by higher TKI medication costs observed during the first year of TKI therapy.

Economic modeling to evaluate the impact of chronic myeloid leukemia therapy management on the oncology care model in the US

Objective: To develop an economic model to evaluate changes in healthcare costs driven by restricting usage of branded tyrosine kinase inhibitors (TKIs) through substitution with generic imatinib among chronic myeloid leukemia (CML) patients in a typical Oncology Care Model (OCM) practice, and examine the impact on Performance-Based Payment (PBP) eligibility. Methods: An Excel-based economic model of an OCM practice with 1,000 cancer patients during a 6-month episode of care was developed. Cancer types and proportions of patients treated in the practice were estimated from an OCM report. All-cause healthcare costs were obtained from published literature. It was assumed that if a practice restricts usage of branded TKIs for newly-diagnosed CML patients, 80% of the market share of branded imatinib and 50% of the market shares of 2^nd-gen TKIs would shift to generic imatinib. Among established TKI-treated patients, it was assumed that 80% of the market share of branded imatinib and no patients treated with 2^nd-gen TKIs would shift to the generic. Results: Four CML patients were estimated for a 1,000-cancer patient OCM practice with a total baseline healthcare cost of $51,345,812 during a 6-month episode. If the practice restricts usage of branded TKIs, the shift from 2^nd-gen TKIs to generic imatinib would reduce costs by $12,970, while shifting from branded to generic imatinib lowers costs by $25,250 during a 6-month episode. Minimum reductions of $3,013,832 in a one-sided risk model and $2,372,010 in a two-sided risk model are required for PBP eligibility; the shift from 2^nd-gen TKIs to generic imatinib would account for 0.4% and 0.5% of the savings required for a PBP, respectively. Conclusions: This analysis indicates that the potential cost reduction associated with restricting branded TKI usage among CML patients in an OCM setting will represent only a small proportion of the cost reduction needed for PBP eligibility.

Tyrosine Kinase Inhibitors Initiation, Cost Sharing, and Health Care Utilization in Patients with Newly Diagnosed Chronic Myeloid Leukemia: A Retrospective Claims-Based Study

BACKGROUND

For newly diagnosed chronic myeloid leukemia (CML) patients, early access to tyrosine kinase inhibitors (TKIs) is a consistent predictor of adherence and optimal response. The expense of targeted therapies, however, may result in high out-of-pocket costs for initiating therapy that could be a barrier to starting treatment.

OBJECTIVE

To examine the association between TKI out-of-pocket costs, initiation, and health care utilization and costs among patients who initiated TKI within 12 months after initial CML diagnosis.

METHODS

Individuals aged 18-64 years with an initial diagnosis of CML were identified in the IBM MarketScan Commercial Database between April 11, 2011, and December 31, 2014. The association between cost sharing and TKI initiation was evaluated using a multivariable logistic regression model applied to patients receiving therapy within a month of diagnosis and within 1-12 months after diagnosis. Health care utilization was compared using negative binomial regression models. Health care cost differences between the 2 patient groups were estimated using generalized linear models. All models were controlled for potential confounding factors.

RESULTS

The study sample consisted of 477 patients, with 397 (83.2%) patients initiating TKI within the first month of CML diagnosis and 80 (16.8%) after the first month. Out-of-pocket costs for the initial 30-day supply of TKI medications were not found to be a significant predictor of TKI initiation time. Patients initiating therapy within a month were less likely to have all-cause hospitalizations (IRR = 0.35; P = 0.02) or CML-specific hospitalizations (IRR = 0.27; P < 0.01). Over the 12-month follow-up period, they incurred $9,923 more in TKI pharmacy costs (P < 0.05), but patients initiating therapy after the first month of diagnosis incurred $7,582 more in medical costs, $218 more in non-TKI pharmacy costs, and $2,680 more in total health care costs (P > 0.05).

CONCLUSIONS

Patients with TKI initiation within the first month of diagnosis had higher TKI pharmacy costs that were partially offset by lower medical and non-TKI pharmacy costs, resulting in lower overall total health care costs. Findings suggest that earlier TKI initiation may reduce the risks of hospitalizations, which could result in potential medical cost savings in the first 12 months of treatment.

DISCLOSURES

No outside funding supported this study. The authors have no relationships or financial interests to report with any entity that would pose a conflict of interest with the subject matter of this article. A poster presentation of the study was made at the 11th American Association for Cancer Research (AACR) Conference on The Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved, on November 2-5, 2018, in New Orleans, LA.

Analytical Validation of a Highly Sensitive, Multiplexed Chronic Myeloid Leukemia Monitoring System Targeting BCR-ABL1 RNA

This study describes the analytical performance of the QuantideX qPCR BCR-ABL IS Kit, the first Food and Drug Administration–cleared assay designed to monitor breakpoint cluster region–Abelson tyrosine-protein kinase 1 (BCR-ABL1) fusion transcripts isolated from peripheral blood specimens from patients with chronic myeloid leukemia. This multiplex real-time quantitative RT-PCR assay amplifies both e13a2 and e14a2 Major BCR-ABL1 transcripts and the reference target ABL1. The test results are provided in international scale (IS) values by incorporating armored RNA-based calibrators that have defined IS values tied directly to the World Health Organization BCR-ABL1 Primary Reference Materials, without the necessity of determining and maintaining conversion factors. For each batch run, the integrated interpretive software evaluates run and specimen quality control metrics (including a sufficient amount of ABL1 control transcripts to ensure a minimal limit of detection) and calculates both molecular response (MR) and %IS values for each specimen. The test has a limit of detection of MR4.7 (0.002%IS) and a linear range from MR0.3 (50%IS) to MR4.7 (0.002%IS) for both Major transcripts. Single-site and multisite precision studies demonstrated a maximum SD of 0.13 MR (30% CV within the assay range between MR0.7 and MR3.7). The performance of this BCR-ABL1 monitoring test meets all of the clinical guideline recommendations for sensitivity and IS reporting for the management of chronic myeloid leukemia patients.

Adherence to tyrosine kinase inhibitors among Medicare Part D beneficiaries with chronic myeloid leukemia

BACKGROUND

Tyrosine kinase inhibitors (TKIs) improve the survival of patients with chronic myeloid leukemia (CML) dramatically; however, nonadherence to TKI therapy may lead to resistance to the therapy. TKIs are very expensive and are covered under Part D insurance for Medicare patients. To the authors' knowledge, the impact of low-income subsidy status and cost sharing on adherence among this group has not been well studied in the literature.

METHODS

Surveillance, Epidemiology, and End Results (SEER) registry data linked with Medicare Part D data from the years 2007 through 2012 were used in the current study. The authors identified 836 patients with CML with Medicare Part D insurance coverage who were new TKI users. Treatment nonadherence was defined as a binary variable indicating the percentage of days covered was <80% during the 180-day period after the initiation of TKI therapy. Logistic regression was used to examine the relationship between out-of-pocket costs per 30-day drug supply, Medicare Part D plan characteristics, and treatment adherence while controlling for other patient characteristics.

RESULTS

Overall, 244 of the 836 patients with CML (29%) were nonadherent to targeted oral therapy during the 180 days after the initiation of treatment with TKIs. The multivariable logistic regression demonstrated that patients with heavily subsidized (odds ratio, 6.7; 95% confidence interval, 2.8-15.9) and moderately subsidized (odds ratio, 3.0; 95% confidence interval, 1.4-6.5) Medicare Part D plans were much more likely to demonstrate nonadherence compared with patients without a subsidy.

CONCLUSIONS

The current population-based study found a significantly higher rate of nonadherence among heavily subsidized patients with substantially lower out-of-pocket costs, which suggests that future research is needed to help lower the nonadherence rate among these individuals. Cancer 2018;124:364-73. © 2017 American Cancer Society.

Evaluation of healthcare resource utilization and incremental economic burden of patients with chronic myeloid leukemia after disease progression to blast phase

AIMS

To evaluate healthcare resource utilization and economic burden of patients with chronic myeloid leukemia (CML) progression to the blast phase.

METHODS

Patients (≥ 18 years) with ≥1 inpatient or ≥2 outpatient CML diagnoses were identified from the MarketScan Commercial and Medicare databases (January 1, 2007-June 30, 2015). CML patients were grouped into two study cohorts, those with evidence of disease progression to the blast phase and those without. Patients were required to have continuous medical and prescription coverage during a 12-month baseline period, in which demographics and clinical characteristics were evaluated. All-cause healthcare resource utilization and costs were evaluated during the baseline period, and a variable follow-up period, lasting ≥1 day and up to 1 year. Generalized linear models (GLM) were used to compare the incremental costs of CML patients with vs without progression.

RESULTS

Of the overall study population, 587 (7%) experienced disease progression and 7,504 (93%) did not. On the index date, of patients with progression, ∼ 31% were treated with allogeneic hematopoietic cell transplant and 69% with chemotherapy. During the baseline period, mean total healthcare costs, including costs for hospitalizations and outpatient costs, were significantly greater for CML patients with progression as compared to those without progression ($143,778 vs $53,143, p < .001). During the follow-up, mean total healthcare costs, costs for hospitalizations, and outpatient medical service costs were substantially greater for patients with progression as compared to those without progression; however, costs for outpatient prescriptions were less for patients who progressed. When patient characteristics were controlled for, mean incremental 1-year cost for CML patients with vs without progression was $270,925 (confidence interval = $235,290-$311,958, p < .001).

CONCLUSIONS

The healthcare burden, in terms of healthcare resource utilization and costs, of patients with CML progression is substantial. Healthcare providers and payers should consider various strategies to minimize the rate of CML progression.

Increasing economic burden of tyrosine kinase inhibitor treatment failure by line of therapy in chronic myeloid leukemia

OBJECTIVE

To assess the economic burden of tyrosine kinase inhibitor (TKI) treatment failure in chronic myeloid leukemia (CML), by assessing all-cause health care resource use (HCRU) and costs in the year after treatment failure by line of therapy (LOT; 1L/2L/3L) using real-world data.

METHODS

Treatment episodes initiating a TKI of interest (index TKI) during June 2008-December 2011 were identified from the IMS PharMetrics Plus Health Plan Claims Database for adult patients with CML diagnosis (ICD-9-CM 205.1x), 120 days pre-index continuous enrollment (CE) and no clinical trial participation. Episodes experiencing treatment failure, defined as switch to a non-index TKI or discontinuation of index TKI (gap of ≥ 60 days), and with 1 year CE post-failure, were analyzed. LOT was determined by number of unique TKIs used in the pre-index. All-cause HCRU and costs (2012 USD) in the 1 year post-failure were assessed by LOT, and the comparisons between 1L and 2L failures were also adjusted using multivariate generalized linear models (GLMs) to control for underlying differences.

RESULTS

A total of 706 episodes were identified (518 1L; 180 2L; 8 3L). Unadjusted HCRU over 1 year post-failure increased significantly. This was accompanied by a significant increase in unadjusted mean costs for 2L failures vs. 1L failures ($99,624 vs. $78,667, p = 0.021, Δ$20,957). Following the adjustment using GLMs, adjusted mean costs were 38% higher (95% CI 1.14-1.68), driven primarily by use of medical services. In adjusted analyses, compared to 1L, 2L failures had: 45% more ambulatory visits (mean 31 vs. 21, 95% CI 1.26-1.66), 75% higher risk of hospitalization (33% vs. 23% hospitalized, 95% CI 1.16-2.64), and 73% higher medical costs (95% CI 1.31-2.29). Medical costs comprised a greater proportion of total costs in 2L vs. 1L (55% vs. 44%); pharmacy costs did not increase significantly.

CONCLUSIONS

The economic burden over 1 year post TKI failure increased with each sequential line of TKI treatment failure.