Initiation of generic imatinib may improve medication adherence for patients with chronic myeloid leukemia

Prior Authorization and Association With Delayed or Discontinued Prescription Fills

PURPOSE

Prior authorization requirements are increasing but little is known about their effects on access to care. We examined the association of a new prior authorization policy with delayed or discontinued prescription fills for oral anticancer drugs among Medicare Part D beneficiaries.

METHODS

Using Medicare part D claims data from 2010 to 2020, we studied beneficiaries regularly filling one of 11 oral anticancer drugs, defined as three 30-day fills in 120 days preceding the plan's prior authorization policy change on that drug and continuously enrolled in the same plan for 120 days before and after the policy change at the start of a new year. The control group consisted of beneficiaries meeting the same utilization criteria, but who were enrolled in plans at the same time that did not implement a prior authorization policy change. The outcomes of interest were discontinuation of the drug within 120 days (analyzed with regression analyses) and time (in days) to next fill after a prior authorization policy change (analyzed using a quasi-experimental difference-in-differences event study).

RESULTS

The introduction of a new prior authorization on an established drug increased the odds of discontinuation within 120 days (adjusted odds ratio, 7.1 [95% CI, 6.0 to 8.5]; P < .001) and increased time to next fill by 9.7 days (95% CI, 8.2 to 11.2; P < .001), relative to patients whose plans did not have a prior authorization policy change.

CONCLUSION

Introduction of a new prior authorization policy on an established drug regimen is associated with increased probability of discontinued and delayed care. For some conditions, this may represent a clinically consequential barrier to access. Waiving prior authorization for patients already established on a drug may improve adherence.

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.

Current evidence on the efficacy and safety of generic imatinib in CML and the impact of generics on health care costs

Since the introduction of imatinib, the management of chronic myeloid leukemia (CML) has changed considerably. Tyrosine kinase inhibitors (TKIs) are the mainstay of CML treatment; however, the high financial burden of TKIs can be problematic for both the patients and health care systems. After the emergence of generics, reimbursement policies of many countries have changed, and generics offered an alternative treatment option for CML patients. There are many papers published on the use of generics in CML patients with conflicting results regarding both efficacy and safety. In this paper, we systematically reviewed the current literature on generic imatinib use in CML, and 36 papers were evaluated. Both in vitro and in vivo studies of generic imatinib showed comparable results with branded imatinib in terms of bioequivalence and bioavailability. In most studies, generics were comparable with the original molecule in terms of efficacy and safety, both in newly diagnosed patients and after switching from Gleevec. Some generic studies showed contradictory findings regarding efficacy and toxicity, and these differences can be attributed to some factors including the use of different generics in different countries. Both in hypothetical models and in real life, introduction of generic imatinib caused significant reduction in health care costs. In conclusion, generics are not inferior to original imatinib in terms of efficacy with an acceptable toxicity profile. Notwithstanding the generally favorable efficacy and safety of generics worldwide to date, we most probably still need more time to draw firmer conclusions on the longer-term outcomes of generics.

The Potential to Reduce Patient Co-Payment and the Public Payer Spending in Poland through an Optimised Implementation of the Generic Substitution: The Win-Win Scenario Suggested by the Real-World Big Data Analysis

High medication costs are one of the major barriers to patient adherence. Medication affordability might be improved by generic substitution. The aim of this study was to assess the effectiveness of the implementation of generic substitution mechanisms in Poland. This was a retrospective analysis of nationwide real-world big data corresponding to dispensation of metformin preparations in 2019 in Poland. Relevant prescription and dispensation data were compared to assess the prevalence of generic substitution and its economic consequences. Among the 1,135,863 e-prescriptions analysed, a generic substitution was found in only 4.81% of the packs dispensed, based on e-prescriptions issued for metformin under its originator version and 2.73% under generic drugs. It is estimated that if these values were applied to the total Polish drug market, patients could lose the opportunity to lower their co-payment by 15.91% and the national payer to reduce its reimbursement expenditures by 8.31%. Our results point at the suboptimal implementation of generic substitution in Poland. Therefore, relevant actions need to be taken in order to maximise the benefits provided by this mechanism. It could not only lead to the win-win scenario in which both patients and the national payer are secured substantial savings, but it could also have a positive impact on patient adherence.

Generic entry of aromatase inhibitors and pharmaceutical access: Initiation of hormonal therapy, timeliness of initiation, and drug choice

BACKGROUND

The trade-offs between innovation and pharmaceutical access are central to the policy debate on drug pricing. High prices may limit access, result in medication underuse, and negatively affect outcomes. Generic drugs make treatments more affordable. Prior research measured access as utilization without a defined population that should receive certain drugs, it is unknown whether generic entry reduces underuse and thus improves access.

OBJECTIVES

To measure changes in access (use, timeliness) with the introduction of three generic aromatase inhibitors (AIs, oral breast cancer drugs) between June 2010 and June 2011.

METHODS

This population-based study included 93,650 older (65+) women diagnosed with hormone receptor-positive breast cancer between 2007 and 2013 in the Surveillance, Epidemiology and End Results-Medicare linked database. We examined changes in access with generic entry for initiation of any adjuvant hormonal therapy drug (AIs or tamoxifen) within one year of diagnosis, time from diagnosis to initiation, and choice of initial therapy.

RESULTS

Among 93,650 newly diagnosed breast cancer cases, 67,372 initiated one of the four drugs. With generic entry, initiation rates increased from 69.5% to 74.3%, but non-initiation remained high (up to 25.7%). After controlling for demographics, clinical factors, and insurance coverage, the probability of initiation increased by 4.6 percentage points (P < 0.001, 95%CI: [4.1,5.2]) after generic entry. With generic entry, estimated time to initiation decreased by 0.3 months (P < 0.001, 95%CI: [0.2,0.3]) from 4.1 months, and the probability of choosing AIs over tamoxifen increased by 5.9 percentage points (P < 0.001, 95%CI: [5.3,6.5]). Patterns did not substantially differ by level of cost-sharing.

CONCLUSIONS

Generic entry of AIs was associated with increased probability of receiving recommended treatments, timeliness of treatment, and the probability of receiving clinically preferred treatments. Price changes with generic entry only partially explained these improvements. High non-initiation rates after generic entry suggest prices are not the sole determinant of access.

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.