Effectiveness and Cost-Effectiveness of Sequential Treatment of Patients with Chronic Myeloid Leukemia in the United States: A Decision Analysis

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.

Routine Histopathologic Examination of Bone Obtained During Elective Primary Total Knee Arthroplasty May Not Be Necessary

Background

Many institutions require the routine collection of pathology samples from every primary total knee arthroplasty (TKA) performed. These policies are controversial, and their cost-effectiveness is difficult to define. We sought to judge the cost-effectiveness of one such policy according to World Health Organization recommendations.

Methods

We analyzed 3200 consecutive primary TKAs, comparing our presumed preoperative diagnoses against the diagnoses made by the pathologist. Diagnoses were categorized as concordant (matching), discrepant (not matching but without impact to patient management), or discordant (not matching and resulting in a direct change to patient management). An incremental cost-utility ratio analysis was performed to determine the cost-effectiveness of our institution's policy to routinely collect pathology samples from every primary TKA performed. Cost-effectiveness was defined by World Health Organization guidelines as a cost of less than $228,090 per quality-adjusted life year gained.

Results

Twelve pathology samples were lost before reaching a pathologist. From the remaining 3188 samples, we identified 3158 concordant cases, 29 discrepant diagnoses, and 1 discordant diagnosis. It cost an estimated $10,522.60 to identify each discrepant diagnosis and an estimated $305,155.36 to diagnose one discordant case in our cohort. Our incremental cost-utility ratio analysis revealed that we spent $305,155.36 to gain 0 quality-adjusted life years for our patients.

Conclusions

Routine histopathologic analysis of TKA samples was cost-ineffective in our patient cohort and may not be necessary during routine TKA.

Inequality in Drug Utilization among Chronic Myeloid Leukaemia Patients in Malaysia: A Cost-Utility Analysis

BACKGROUND

The burden of chronic myeloid leukaemia (CML) is increasing due to longer patient survival, better life expectancy of the general population, and increasing drug prices. Funding is one of the main concerns in the choice of CML medication used worldwide; thus, patient assistance programmes were introduced to ensure accessibility to affordable treatment. In this study, we evaluated CML drug distribution inequality in Malaysia through patient assistance programmes, using pharmaco-economics methods to evaluate CML treatment from the care provider's perspective.

METHODS

Patients with CML were recruited from outpatient haematological clinics at the national centre of intervention and referral for haematological conditions and a public teaching hospital. The health-related quality of life or utility scores were derived using the EuroQol EQ-5D-5L questionnaire. Costing data were obtained from the Ministry of Health Malaysia Casemix MalaysianDRG. Imatinib and nilotinib drug costs were obtained from the administration of the participating hospitals and pharmaceutical company.

RESULTS

Of the 221 respondents in this study, 68.8% were imatinib users. The total care provider cost for CML treatment was USD23,014.40 for imatinib and USD43,442.69 for nilotinib. The governmental financial assistance programme reduced the total care provider cost to USD13,693.51 for imatinib and USD19,193.45 for nilotinib. The quality-adjusted life years (QALYs) were 17.87 and 20.91 per imatinib and nilotinib user, respectively. Nilotinib had a higher drug cost than imatinib, yet its users had better life expectancy, utility score, and QALYs. Imatinib yielded the lowest cost per QALYs at USD766.29.

CONCLUSION

Overall, imatinib is more cost-effective than nilotinib for treating CML in Malaysia from the care provider's perspective. The findings demonstrate the importance of cancer drug funding assistance for ensuring that the appropriate treatments are accessible and affordable and that patients with cancer use and benefit from such patient assistance programmes. To establish effective health expenditure, drug distribution inequality should be addressed.

A Systematic Literature Review of the Economic Evaluations of Treatments for Patients with Chronic Myeloid Leukemia

BACKGROUND AND OBJECTIVES

The management of chronic myeloid leukemia is associated with an extensive economic burden, and as novel interventions are being tested in this disease, understanding the comparative effectiveness is of interest. Findings and conclusions of this important issue continue to evolve with improvements in clinical research and economic understanding. This systematic literature review aims to conduct a comprehensive assessment of economic evaluations in chronic phase chronic myeloid leukemia.

METHODS

Embase^®, MEDLINE^®, and the National Health Service Economic Evaluation Database were searched on 4 July, 2022 to identify economic evaluations of chronic myeloid leukemia. Health technology assessment websites and key conference proceedings were also searched. Economic evaluations comparing treatment options in adult patients with chronic phase chronic myeloid leukemia were included. The quality of the studies were assessed using Drummond's checklists.

RESULTS

The search retrieved 47 studies and 16 health technology assessments that fulfilled the eligibility criteria. Most were cost-utility analyses (23 studies and 11 health technology assessments) and were from the USA (n = 15) and China (n = 7). Twenty-seven studies and six health technology assessments included only patients with chronic phase chronic myeloid leukemia. Most models had a Markov structure, a 1 year to lifetime time horizon, and a 1-month cycle length. Commonly assessed treatments were various tyrosine kinase inhibitors (imatinib, nilotinib, dasatinib, bosutinib, and ponatinib) and other interventions such as interferon-α, hydroxyurea, and allogeneic stem cell transplant.

CONCLUSIONS

In patients with newly diagnosed chronic myeloid leukemia, imatinib regimens were cost effective, mostly owing to the availability of generics. Nilotinib and dasatinib were generally cost effective as second-line agents for patients who were resistant or intolerant to imatinib. Though progress has been made to better characterize the cost effectiveness of first-line and second-line chronic myeloid leukemia therapies, the paucity of published cost-effectiveness studies of third-line treatments increases the uncertainty associated with economic evaluations of later lines of therapy.

Conceptual Framework and Methodological Challenges for Modeling Effectiveness in Oncology Treatment Sequence Models

In this review, we summarize the challenges faced by existing oncology treatment sequence decision models and introduce a general framework to conceptualize such models. In the proposed framework, patients with cancer receive at least two lines of therapy (LOTs) followed by palliative care throughout their lifetime. Patients cycle through progression-free and progressive disease health states in each LOT before death. Under this framework, four broad aspects of modeling effectiveness of treatment sequences need exploration. First, disease progression, treatment discontinuation, and the relationship between the two events should be considered. Second, the effectiveness of each LOT depends on its placement in a treatment sequence as the effectiveness of later LOTs may be influenced by the earlier LOTs. Third, the treatment-free interval (TFI; time between discontinuation of earlier LOT and initiation of later LOT) may impact a therapy's effectiveness. Fourth, in the absence of head-to-head trials directly comparing LOTs, indirect treatment comparison (ITC) of outcomes for a specific LOT or even for the entire treatment sequence is important to consider. A search of decision models that estimated effectiveness of at least two lines of oncology therapy was conducted in PubMed (N = 20) and technology appraisals by the National Institute for Health and Care Excellence (N = 26) to assess four methodological aspects related to the model framework: (1) selection of outcomes for effectiveness in a treatment sequence, (2) approaches to adjust the efficacy of a treatment in consideration of its place in the sequence, (3) approaches to address TFIs between LOTs, and (4) incorporation of ITCs to estimate comparators' effectiveness in the absence of direct head-to-head evidence. Most models defined health states based on disease progression on different LOTs while estimating treatment duration outside of the main model framework (30/46) and used data from multiple data sources in different LOTs to model efficacy of a treatment sequence (41/46). No models adjusted efficacy for the characteristics of patients who switched from an earlier LOT to a later LOT or adjusted for the impact of prior therapies, and just six models considered TFIs. While 11 models applied ITC results to estimate efficacy in comparator treatment sequences, the majority limited the ITC to one LOT in the sequence. Thus, there is substantial room to improve the estimation of effectiveness for treatment sequences using existing data when comparing effectiveness of alternative treatment sequences.

Cost-Effectiveness of Bosutinib for the Treatment of Adult Patients with Chronic Phase Chronic Myeloid Leukemia in the Second-Line Setting

BACKGROUND

A recently conducted matching-adjusted indirect comparison demonstrated that bosutinib improved progression-free survival, and delayed progression to advanced disease compared with dasatinib and nilotinib in patients with second line (2L) chronic-phase chronic myeloid leukemia (CP-CML). However, the long-term clinical and economic impact of using bosutinib versus dasatinib and nilotinib has not been evaluated. The objective was to determine the cost-effectiveness of bosutinib compared with dasatinib and bosutinib compared with nilotinib from a US payer perspective.

METHODS

A cost-effectiveness model was developed using partition survival methods and three health states: progression-free, progression, and death. Trial data (individual patient-level and aggregate-level data) informed the progression-free and overall survival estimates. Costs included drugs and medical resource use. Utility values were obtained from literature. Sensitivity analyses (SAs) included one-way and probabilistic sensitivity analyses (PSAs).

RESULTS

Comparing bosutinib versus dasatinib resulted in a gain of 0.4 discounted life years, 1.5 quality-adjusted life years (QALYs), and incremental costs of $28,459 (values in 2020 US dollars), for an incremental cost-effectiveness ratio (ICER) of $19,811/QALY gained. Comparing bosutinib versus nilotinib resulted in a gain of 0.8 discounted life-years, 1.8 QALYs, and incremental costs of $76,563, for an ICER of $41,932/QALY gained. Drug costs and extrapolation distribution type were the main drivers of the model in the one-way SAs. In the PSAs, bosutinib had >90% and >80% probabilities of being cost-effective at a willingness-to-pay threshold of $100,000/QALY versus dasatinib and nilotinib, respectively.

CONCLUSIONS

Our results suggest that compared with dasatinib and nilotinib, bosutinib may represent good value for money for treating 2L CP-CML patients.

Health-related quality of life using EQ-5D among chronic myeloid leukaemia patients in health centres in Klang Valley, Malaysia

Chronic Myeloid Leukaemia (CML) responds well with the targeted therapy drugs, Tyrosine Kinase Inhibitors (TKI), that give potentially long-term disease control for the patients. The objective of this study was to determine the disease burden and factors influencing the health-related quality of life (HRQoL) and health status of CML patients in Klang Valley, Malaysia. CML patients were recruited from haematological outpatient clinics in health centres in Klang Valley, Malaysia. A semi-guided self-administered questionnaire was used. HRQoL was measured by EQ-5D utility value and health status was by visual analogue score (VAS). Logistic regression analysis was conducted to determine the factors influencing HRQoL and health status. A total of 221 respondents participated, where more than half were Malay (56.6%), male (53.4%), and an Imatinib user (68.8%). Majority were diagnosed at the chronic phase (89.5%). The mean age of diagnosis was 41 years old. Significant determinant associated with HRQoL was age of diagnosis. These factors had no significant effect on the HRQoL of these patients regardless of types of TKI used and initial phase of CML. The overall HRQoL of CML patients were comparable to, if not higher, than the general population. Any TKI that was good enough to eliminate disease symptoms and erase patient's worries, can possibly make CML patients have a better quality of life than typical cancer patients and even the general population.

Cost effectiveness of therapeutic drug monitoring for imatinib administration in chronic myeloid leukemia

BACKGROUND

Imatinib mesylate (IM) is a first-line treatment option for patients with chronic myeloid leukemia (CML). Patients who fail or are intolerant to IM therapy are treated with more expensive second and third-generation tyrosine kinase inhibitors. Patients show wide variation in trough concentrations in response to standard dosing. Thus, many patients receive subtherapeutic or supratherapeutic doses. Therapeutic drug monitoring (TDM) may improve dose management that, in turn, may reduce costs and improve outcomes. However, TDM also adds to the cost of patient care. The objective of this study was to determine the cost-effectiveness of TDM for generic IM therapy.

METHODS

We developed a microsimulation model for the trough plasma concentration of IM which is related to a cytogenetic or molecular response. We compared two cohorts: one with TDM and one without TDM (NTDM). The lifetime incremental cost-effectiveness ratio (ICER) was calculated using quality-adjusted life years (QALYs) as the effectiveness measure. One-way and probabilistic sensitivity analyses were performed.

RESULTS

The lifetime cost and QALY of treatment with TDM were $2,137K [95% Ci: 2,079K; 2,174K] and 12.37 [95% CI: 12.07; 12.55], respectively. The cost and QALY of NTDM were $2,132K [95% CI: 2,091K; 2,197K] and 12.23 [95% CI: 11.96; 12.50], respectively. The incremental cost and QALY for TDM relative to NTDM was $4,417 [95% CI: -52,582; 32,097]) and 0.15 [95% CI: -0.13; 0.28]. The ICER for TDM relative to NTDM was $30,450/QALY. Probabilistic sensitivity analysis showed that TDM was cost-effective relative to NTDM in 90% of the tested scenarios at a willingness-to-pay threshold of $100,000/QALY.

CONCLUSIONS

Although the impact of TDM is modest, the cost-effectiveness over a lifetime horizon (societal perspective, ($30,450/QALY) falls within the acceptable range (< $100k/QALY).

Economic Evaluations of Tyrosine Kinase Inhibitors for Patients with Chronic Myeloid Leukemia in Middle- and High-Income Countries: A Systematic Review

OBJECTIVES

The objective of this systematic review was to conduct a comprehensive assessment of economic evaluations of tyrosine kinase inhibitors (TKIs) in patients with chronic myeloid leukemia (CML) in middle- and high-income countries.

METHODS

A literature search was conducted in Embase, MEDLINE (via PubMed) and the Cochrane library on March 3, 2018 to identify economic evaluations of chronic myeloid leukemia that met the inclusion criteria. Data on such parameters as patient characteristics, cost components, and main outcomes were extracted from eligible studies.

RESULTS

The literature review retrieved 798 studies, 17 of which fulfilled the eligibility criteria. Eight studies included an economic analysis on newly diagnosed patients with CML. Seven studies investigated people with CML who were resistant or intolerant to standard-dose imatinib. One article focused on chronic phase (CP)-CML patients who experienced failure with first-line treatment for interferon-α. The last study investigated advanced stages of CML patients. Most studies (n = 70.6%) were conducted in high-income countries. Only five studies (n = 29.4%) were performed in middle-income countries. Most studies used a Markov model. The time horizon varied from six months to life-time.

CONCLUSIONS

Despite high costs, the included studies indicate that imatinib regimens are cost effective in newly diagnosed patients with CP-CML. For people with CML who are resistant or intolerant to standard-dose imatinib, dasatinib is likely to be a more cost-effective strategy in middle-income countries. More studies are necessary to assess the long-term efficacy and cost effectiveness of novel treatment options.

Analysis of adverse events associated with dasatinib and nilotinib treatments in chronic-phase chronic myeloid leukemia patients outside clinical trials

We analyzed adverse events (AEs) in 201 chronic phase CML patients treated with nilotinib (n = 120) or dasatinib (n = 81) as first- or second-line therapy. The dasatinib group had significantly higher grade 3-4 AEs compared to the nilotinib group (22 vs. 54%, p < 0.001), and had more frequent dose reduction, interruption, and discontinuation (p < 0.001, p = 0.004, and p = 0.006, respectively). Of 59 patients who discontinued treatment, 47 (80%) discontinued treatment due to AEs; 50% of the AEs causing drug discontinuation were of grade 2 severity. Compared to the second-line setting, discontinuation occurred more rapidly in the first-line setting (2.9 vs. 15.6 months, p = 0.015). Pleural effusion occurred in 35% (28/81) of the patients with dasatinib and led to dasatinib discontinuation in 14 patients (grade 2 of 79%). Pulmonary artery hypertension occurred in one patient with dasatinib. Stroke, acute coronary syndrome, and peripheral artery occlusive disease occurred in 5% (6/120) of the patients treated with nilotinib. The dasatinib group had shorter event-free survival than nilotinib group (first-line, p = 0.051; second-line, p = 0.025). In the clinical practice setting, nilotinib or dasatinib use was more frequently interrupted than recommended by guidelines in association with less severe AEs. We believe this phenomenon is attributable to the availability of other TKIs.

Nilotinib versus dasatinib as second-line therapy in patients with Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase who are resistant or intolerant to imatinib: a cost-effectiveness analysis based on real-world data

OBJECTIVE

To evaluate the cost-effectiveness of second-line nilotinib vs dasatinib among patients with Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase (Ph+ CML-CP) who are resistant or intolerant to imatinib, from a US third-party perspective.

METHODS

A lifetime partitioned survival model was developed to compare the costs and effectiveness of nilotinib vs dasatinib, which included four health states: CP on treatment, CP post-discontinuation, progressive disease (accelerated phase [AP] or blast crisis [BC]), and death. Time on treatment, progression-free survival, and overall survival of nilotinib and dasatinib were estimated using real-world comparative effectiveness data. Parametric survival models were used to extrapolate outcomes beyond the study period. Drug treatment costs, medical costs, and adverse event costs were obtained from the literature and publicly available databases. Utilities of health states were derived from the literature. Incremental cost-effectiveness ratios, including incremental cost per life-year (LY) gained and incremental cost per quality-adjusted life-year (QALY) gained, were estimated comparing nilotinib and dasatinib. Deterministic sensitivity analyses were performed by varying patient characteristics, cost, and utility inputs.

RESULTS

Over a lifetime horizon, nilotinib-treated patients were associated with 11.7 LYs, 9.1 QALYs, and a total cost of $1,409,466, while dasatinib-treated patients were associated with 9.5 LYs, 7.3 QALYs, and a total cost of $1,422,122. In comparison with dasatinib, nilotinib was associated with better health outcomes (by 2.2 LYs and 1.9 QALYs) and lower total costs (by $12,655). Deterministic sensitivity analysis results showed consistent findings in most scenarios.

LIMITATIONS

In the absence of long-term real-world data, the lifetime projection could not be validated.

CONCLUSIONS

Compared with dasatinib, second-line nilotinib was associated with better life expectancy, better quality-of-life, and lower costs among patients with Ph+ CML-CP who were resistant or intolerant to imatinib.