Population-based utilization and costs associated with tyrosine kinase inhibitors for first-line treatment of chronic myelogenous leukemia among elderly patients

BACKGROUND: Following approval of imatinib, a breakthrough tyrosine kinase inhibitor (TKI), survival significantly improved by more than 20% since 2001 among treated chronic myelogenous leukemia (CML) patients. Subsequently, more expensive second-generation TKIs with varying selectivity profiles have been approved. Population-based studies are needed to evaluate the real-world utilization of TKI therapies, particularly given their escalating costs and recommendations for maintenance therapy. OBJECTIVE: To assess the utilization patterns of first-line TKIs, overall and by specific agent, among elderly CML patients in the United States, and the cost implications. METHODS: CML patients aged 65 years and older at diagnosis between 2007 and 2015 were identified from population-based cancer registries in the linked Surveillance, Epidemiology, and End Results (SEER)-Medicare database. The percentage of CML patients receiving imatinib, dasatinib, or nilotinib within the first year of diagnosis was calculated along with time to first-line treatment initiation. Bivariate comparisons and Cox proportional hazards models were used to identify factors associated with TKI initiation. Average monthly patient responsibility, including patient out-of-pocket (OOP) costs, stratified by Part D low-income subsidy (LIS) status were also calculated. RESULTS: Among the 1,589 CML patients included, receipt of any TKI within 1 year of diagnosis increased from 66.2% to 78.9%. In 2015, the distribution of first-line TKI therapies was 41.3% imatinib, 28.3% dasatinib, and 9.3% nilotinib. Almost 60% of patients initiated TKI treatment within 3 months of diagnosis. Multivariable analysis indicated that TKI use in the first year was lower among the very elderly (aged > 75 years vs. 65-69 years: HR = 0.72; 95% CI = 0.63-0.83), patients with more comorbidities (Hierarchical Condition Category risk score > 2 vs. HR = 0.74, 95% CI = 0.62-0.88), and patients ineligible for LIS (HR = 0.75; 95% CI = 0.65-0.87). Average monthly patient OOP cost was significantly lower for LIS-eligible versus LIS-ineligible patients: imatinib (2016: $12 vs. $487), dasatinib (2016: $34 vs. $557), and nilotinib (2016: $1 vs. $526). CONCLUSIONS: TKI use has increased significantly since 2007. While imatinib remained the most frequently prescribed first-line agent, by 2015 newer TKIs represented one third of the market share. Utilization patterns indicated persistent age, comorbidity, and financial barriers. TKI use is indicated for long-term therapy, and increased adoption of newer, more expensive agents raises concerns about the sustained affordability of CML treatment, particularly among unsubsidized patients. DISCLOSURES: No outside funding supported this study. There are no reported conflicts of interest.

Financial Implications of Avapritinib for Treatment of Unresectable Gastrointestinal Stromal Tumors in Patients With a PDGFRA Exon 18 Variant or After 3 Previous Therapies in a Hypothetical US Health Plan

IMPORTANCE

With the approval of avapritinib for adults with unresectable or metastatic gastrointestinal stromal tumors (GISTs) harboring a platelet-derived growth factor receptor alpha (PDGFRA) exon 18 variant, including PDGFRA D842V variants, and National Comprehensive Cancer Network guideline recommendations as an option for patients with GIST after third-line treatment, it is important to estimate the potential financial implications of avapritinib on a payer's budget.

OBJECTIVE

To estimate the budget impact associated with the introduction of avapritinib to a formulary for metastatic or unresectable GISTs in patients with a PDGFRA exon 18 variant or after 3 or more previous treatments from the perspective of a US health plan.

DESIGN, SETTING, AND PARTICIPANTS

For this economic evaluation, a 3-year budget impact model was developed in March 2020, incorporating costs for drug acquisition, testing, monitoring, adverse events, and postprogression treatment. The model assumed that avapritinib introduction would be associated with increased PDGFRA testing rates from the current 49% to 69%. The health plan population was assumed to be mixed 69% commercial, 22% Medicare, and 9% Medicaid. Base case assumptions included a GIST incidence rate of 9.6 diagnoses per million people, a metastatic PDGFRA exon 18 mutation rate of 1.9%, and progression rate from first-line to fourth-line treatment of 17%.

EXPOSURES

The model compared scenarios with and without avapritinib in a formulary.

MAIN OUTCOMES AND MEASURES

Annual, total, and per member per month (PMPM) budget impact.

RESULTS

In a hypothetical 1-million member plan, fewer than 0.1 new patients with a PDGFRA exon 18 variant per year and 1.2 patients receiving fourth-line therapy per year were eligible for treatment. With avapritinib available, the total increase in costs in year 3 for all eligible adult patients with a PDGFRA exon 18 variant was $46 875, or $0.004 PMPM. For patients undergoing fourth-line treatment, the total increase in costs in year 3 was $69 182, or $0.006 PMPM. The combined total budget impact in year 3 was $115 604, or $0.010 PMPM, including an offset of $3607 in postprogression costs avoided or delayed. The higher rates of molecular testing resulted in a minimal incremental testing cost of $453 in year 3.

CONCLUSIONS AND RELEVANCE

These results suggest that adoption of avapritinib as a treatment option would have a minimal budget impact to a hypothetical US health plan. This would be primarily attributable to the small eligible patient population and cost offsets from reduced or delayed postprogression costs.

Cost-Effectiveness of First-Line Tyrosine Kinase Inhibitor Therapy Initiation Strategies for Chronic Myeloid Leukemia

OBJECTIVES

Overall survival in chronic myeloid leukemia (CML) in chronic phase is not significantly different by treatment with first-line tyrosine kinase inhibitors (TKIs), but emerging evidence reveals differences in costs and safety profiles. We evaluated the 1-year cost-effectiveness of TKI initiation with imatinib, dasatinib, or nilotinib among a hypothetical cohort of incident patients with CML from a US payer's perspective.

METHODS

We constructed a decision analytic model to assess quality-adjusted life years (QALYs), healthcare costs, net monetary benefit, and incremental cost-effectiveness of treatment strategies. We used published studies and data from the IBM Watson Health MarketScan database for model parameters. To calculate TKI costs, we used the 2018 Federal Supply Schedule estimates for generic imatinib and branded second-generation TKIs. We evaluated cost-effectiveness under various willingness-to-pay thresholds. We accounted for uncertainty with deterministic and probabilistic sensitivity analyses.

RESULTS

In the base-case analysis, imatinib was favored over dasatinib and nilotinib at a lower cost per QALY gained. Imatinib remained the favored strategy after 1-way variations in TKI costs, TKI switching, QALYs, adverse event risk, and CML progression. When we assessed model uncertainty with prespecified parameter distributions, imatinib was cost-saving compared with dasatinib in 40% of 100 0000 simulations and was favored over all simulations compared with nilotinib. First-line treatment with second-generation TKIs was cost-effective in 50% of simulations at a $200 000/QALY willingness-to-pay threshold.

CONCLUSIONS

Generic availability of imatinib provides a more cost-effective treatment approach in the first year compared with other available TKIs for newly diagnosed patients with CML.

Cost-effectiveness Analysis of Genetic Testing and Tailored First-Line Therapy for Patients With Metastatic Gastrointestinal Stromal Tumors

IMPORTANCE

Gastrointestinal stromal tumor (GIST) is frequently driven by oncogenic KIT variations. Imatinib targeting of KIT marked a new era in GIST treatment and ushered in precision oncological treatment for all solid malignant neoplasms. However, studies on the molecular biological traits of GIST have found that tumors respond differentially to imatinib dosage based on the KIT exon with variation. Despite this knowledge, few patients undergo genetic testing at diagnosis, and empirical imatinib therapy remains routine. Barriers to genetic profiling include concerns about the cost and utility of testing.

OBJECTIVE

To determine whether targeted gene testing (TGT) is a cost-effective diagnostic for patients with metastatic GIST from the US payer perspective.

DESIGN, SETTING, AND PARTICIPANTS

This economic evaluation developed a Markov model to compare the cost-effectiveness of TGT and tailored first-line therapy compared with empirical imatinib therapy among patients with a new diagnosis of metastatic GIST. The main health outcome, quality-adjusted life years (QALYs), and costs were obtained from the literature, and transitional probabilities were modeled from disease progression and survival estimates from randomized clinical trials of patients with metastatic GIST. Data analyses were conducted October 2019 to January 2020.

EXPOSURE

TGT and tailored first-line therapy.

MAIN OUTCOMES AND MEASURES

The primary outcome was QALYs and cost. Cost-effectiveness was defined using an incremental cost-effectiveness ratio, with an incremental cost-effectiveness ratio less than $100 000/QALY considered cost-effective. One-way and probabilistic sensitivity analyses were conducted to assess model stability.

RESULTS

Therapy directed by TGT was associated with an increase of 0.10 QALYs at a cost of $9513 compared with the empirical imatinib approach, leading to an incremental cost-effectiveness ratio of $92 100. These findings were sensitive to the costs of TGT, drugs, and health utility model inputs. Therapy directed by TGT remained cost-effective for genetic testing costs up to $3730. Probabilistic sensitivity analysis found that TGT-directed therapy was considered cost-effective 70% of the time.

CONCLUSIONS AND RELEVANCE

These findings suggest that using genetic testing to match treatment of KIT variations to imatinib dosing is a cost-effective approach compared with empirical imatinib.

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.

Healthcare and economic burden of adverse events among patients with chronic myelogenous leukemia treated with BCR-ABL1 tyrosine kinase inhibitors

OBJECTIVES

BCR-ABL1 tyrosine kinase inhibitors (TKIs) are established treatments for chronic myelogenous leukemia (CML); however, they are associated with infrequent, but clinically serious adverse events (AEs). The objective of this analysis was to assess healthcare resource utilization and costs associated with AEs, previously identified using the FDA Adverse Event Reporting System (FAERS) in another study, among TKI-treated patients.

METHODS

Adult patients with ≥1 inpatient or ≥2 outpatient ICD-9-CM diagnosis codes for CML and ≥1 claim for a TKI treatment between January 1, 2006 and September 30, 2012 were identified from the Commercial and Medicare MarketScan databases. The first claim for a TKI was designated as the index event. Patients were required to have no TKI treatment during a 12-month baseline period. Healthcare resource utilization and costs associated with select AEs having the strongest association with TKI treatment (femoral arterial stenosis [FAS], peripheral arterial occlusive disease [PAOD], intermittent claudication, coronary artery stenosis [CAS], pericardial effusion, pleural effusion, malignant pleural effusion, conjunctival hemorrhage) were evaluated during a 12-month follow-up period.

RESULTS

The study sample included 2,005 CML patients receiving TKI therapy (mean age = 56 years; 56% male). Among all evaluated AEs, the highest mean inpatient healthcare costs were observed for FAS ($16,800 per patient) and PAOD ($14,263 per patient), which had total mean medical costs (inpatient + outpatient) of $17,015 and $15,154 per patient, respectively. Mean outpatient healthcare costs were highest for CAS ($1,861 per patient), followed by intermittent claudication ($947 per patient), PAOD ($891 per patient), and pleural effusion ($890 per patient). Total mean medical costs for fluid retention-related AEs, including pericardial effusion and pleural effusion, were $2,797 and $1,908 per patient, respectively.

CONCLUSIONS

The healthcare costs of AEs identified in the FAERS as having the strongest association with TKI treatment are substantial. Vascular stenosis-related AEs, including FAS and PAOD, have the highest cost burden.

An economic analysis of high-dose imatinib, dasatinib, and nilotinib for imatinib-resistant chronic phase chronic myeloid leukemia in China: A CHEERS-compliant article

BACKGROUND

The aim of the study was to test the cost-effectiveness of dasatinib compared to high-dose imatinib and nilotinib in Chinese patients who were diagnosed with imatinib-resistant chronic myeloid leukemia in the chronic phase (CML-CP).

METHODS

A Markov model combined with clinical effectiveness, utility, and cost data was used. The sensitivity analyses were conducted to determine the robustness of the model outcomes. The impact of patient assistance programs (PAPs) was assessed.

RESULTS

Treatment with dasatinib is expected to produce 3.65, 0.59, and 0.15 more quality-adjusted life years (QALYs) in comparison with high-dose imatinib (600 and 800 mg) and nilotinib, respectively. When a PAP was available, dasatinib yielded an incremental cost of $16,417 per QALY compared to imatinib (600 mg) and was cost-saving compared to imatinib (800 mg) and nilotinib.

CONCLUSION

When PAP is available in the Chinese setting, dasatinib is likely to be a cost-effective strategy for patients with CML-CP standard-dose imatinib resistance. The results should be carefully explained due to the assumptions and limitations used in the study.

Societal implications of medical insurance coverage for imatinib as first-line treatment of chronic myeloid leukemia in China: a cost-effectiveness analysis

OBJECTIVES

Imatinib (Glivec) and nilotinib (Tasigna) have been covered by critical disease insurance in Jiangsu province of China since 2013, which changed local treatment patterns and outcomes of patients with chronic myeloid leukemia (CML). This study evaluated the long-term cost-effectiveness of insurance coverage with imatinib as the first-line treatment for patients with CML in China from a societal perspective.

METHODS

A decision-analytic model based on previously published and real-world evidence was applied to simulate and evaluate the lifetime clinical and economic outcomes associated with CML treatments before and after imatinib was covered by medical insurance. Incremental cost-effectiveness ratio (ICER) was calculated with both costs and quality-adjusted life years (QALYs) discounted at 3% annually. Different assumptions of treatment benefits and costs were taken to address uncertainties and were tested with sensitivity analyses.

RESULTS

In base case analysis, both cost and effectiveness of CML treatments increased after imatinib was covered by the medical insurance; on average, the incremental QALY and cost were 5.5 and ¥277,030 per patient in lifetime, respectively. The ICER of insurance coverage with imatinib was ¥50,641, which is less than the GDP per capita of China. Monte Carlo simulation resulted in the estimate of 100% probability that the insurance coverage of imatinib is cost-effective. Total cost was substantially saved at 5 years after patients initiated imatinib treatment with insurance coverage compared to no insurance coverage, the saved cost at 5 years was ¥99,565, which included the cost savings from both direct (e.g. cost of bone marrow or stem cell transplant) and indirect costs (e.g. productivity loss of patients and care-givers).

CONCLUSIONS

The insurance coverage of imatinib is very cost-effective in China, according to the local cost and clinical data in Jiangsu province. More importantly, the insurance coverage of imatinib and nilotinib have changed the treatment patterns of CML patients, thus dramatically increasing life expectancy and quality-of-life (QoL) saving on productivity losses for both CML patients and their caregivers.

The impact of medical insurance coverage and molecular monitoring frequency on outcomes in chronic myeloid leukemia: real-world evidence in China

OBJECTIVES

Imatinib (Glivec) has been covered by critical disease insurance for treatment of chronic myeloid leukemia (CML) in Jiangsu province of China since 2013. Further, free molecular monitoring has been provided to patients at top clinical centers as part of a pilot study that has changed the local treatment pattern and outcomes of patients with CML. This study evaluates the impact of medical insurance coverage and the molecular monitoring frequency on outcomes of patients with CML treated at a central hospital in Jiangsu, China, according to patient-level data.

METHODS

The study investigated 335 CML patients receiving medical treatment in a central hospital between January 1, 2011 and December 31, 2014. Demographic and clinical characteristics were extracted from the patients' clinical records. Univariate and multivariate analyses using the logistic regression model were performed to identify the differences in outcomes of major molecular response (MMR) or complete cytogenetic response (CCyR) between patients who were insured vs uninsured, or between patients with frequency of PCR monitoring ≤2 times vs ≥3 times per year.

RESULTS

Both the achievement of MMR (BCR-ABL^IS ≤0.1%) (50.4% vs 37.5%) and CCyR (80.7% vs 62.8%) at 12 months have shown significant differences that favored patients with insurance coverage of imatinib, while there was no significant difference in the outcome of BCR-ABL^IS ≤1% between insured and non-insured groups (56.0% vs 51.3%) at 6 months. The long-term results at 24 months demonstrated that there was a statistically significant difference in MMR rates between the group with 3 or more PCR monitoring tests per year and the group of patients with 2 or less PCR tests per year (76.9% vs 52.2%).

CONCLUSIONS

The study findings suggest that CML patients benefit from insurance coverage of imatinib and higher frequency (≥3) of regularly scheduled molecular monitoring PCR in China.

Target prices for mass production of tyrosine kinase inhibitors for global cancer treatment

OBJECTIVE

To calculate sustainable generic prices for 4 tyrosine kinase inhibitors (TKIs).

BACKGROUND

TKIs have proven survival benefits in the treatment of several cancers, including chronic myeloid leukaemia, breast, liver, renal and lung cancer. However, current high prices are a barrier to treatment. Mass production of low-cost generic antiretrovirals has led to over 13 million people being on HIV/AIDS treatment worldwide. This analysis estimates target prices for generic TKIs, assuming similar methods of mass production.

METHODS

Four TKIs with patent expiry dates in the next 5 years were selected for analysis: imatinib, erlotinib, lapatinib and sorafenib. Chemistry, dosing, published data on per-kilogram pricing for commercial transactions of active pharmaceutical ingredient (API), and quotes from manufacturers were used to estimate costs of production. Analysis included costs of excipients, formulation, packaging, shipping and a 50% profit margin. Target prices were compared with current prices. Global numbers of patients eligible for treatment with each TKI were estimated.

RESULTS

API costs per kg were $347-$746 for imatinib, $2470 for erlotinib, $4671 for lapatinib, and $3000 for sorafenib. Basing on annual dose requirements, costs of formulation/packaging and a 50% profit margin, target generic prices per person-year were $128-$216 for imatinib, $240 for erlotinib, $1450 for sorafenib, and $4020 for lapatinib. Over 1 million people would be newly eligible to start treatment with these TKIs annually.

CONCLUSIONS

Mass generic production of several TKIs could achieve treatment prices in the range of $128-$4020 per person-year, versus current US prices of $75161-$139,138. Generic TKIs could allow significant savings and scaling-up of treatment globally, for over 1 million eligible patients.

The economic burden of gastrointestinal stromal tumor (GIST) recurrence in patients who have received adjuvant imatinib therapy

OBJECTIVE

To estimate the economic burden of gastrointestinal stromal tumor (GIST) recurrence in patients who received imatinib adjuvant therapy.

METHODS

Data from the MarketScan and PharmMetrics databases between January 2000 and March 2013 were extracted. Patients who had received at least one diagnosis of GIST, had undergone a primary surgery for GIST, and had received at least one prescription for imatinib were included in the analysis. An algorithm was applied to identify those who had a subsequent GIST recurrence. Patients who experienced a recurrence and those who did not have a recurrence were compared for differences in healthcare utilization measures and healthcare costs within 6 months after the recurrence, while adjusting for potential confounding factors.

RESULTS

A total of 540 patients with primary resectable GIST who received imatinib adjuvant therapy were identified, including 444 (82.2%) patients who did not experience GIST recurrence and 96 (17.8%) patients who did experience recurrence. Patients who experienced GIST recurrence utilized significantly more healthcare resources in all categories than patients who did not have a recurrence, including the number of hospitalizations, days of hospitalization, emergency room visits, outpatient visits, and other medical services (all p-values <0.01). The total healthcare cost was significantly higher for patients with GIST recurrence, with a difference of $4464 per patient per month (p < 0.01). Both the medical and pharmacy costs were significantly higher with adjusted differences of $3488 and $1423 per patient per month, respectively (both p-values <0.01).

CONCLUSIONS

Patients who had GIST recurrence after surgical resection incurred significantly more healthcare resource utilization and greater healthcare costs within 6 months after the recurrence than patients who did not have recurrence. These findings suggest that GIST recurrence is associated with a substantial economic burden.