Baseline characteristics and secondary medication adherence among Medicare patients diagnosed with transthyretin amyloid cardiomyopathy and/or receiving tafamidis prescriptions: A retrospective analysis of a Medicare cohort.

BACKGROUND: Transthyretin amyloid cardiomyopathy (ATTR-CM) is an underdiagnosed, life-threatening condition that mostly affects older persons. In May 2019, regulatory approval of tafamidis provided the first pharmacologic treatment of ATTR-CM. In the pivotal phase 3 Transthyretin Amyloidosis Cardiomyopathy Clinical Trial (ATTR-ACT), 97.2% of patients were classified as adherent (defined as taking ≥ 80% of scheduled doses). Given its recent approval, there is limited real-world evidence examining patient adherence to tafamidis. OBJECTIVE: To evaluate adherence patterns, demographics, and clinical characteristics of patients in the United States receiving tafamidis prescriptions through Medicare. Secondarily, we aimed to evaluate concomitant medications filled by this patient population. METHODS: We conducted a retrospective cohort study of US Medicare claims data, limited by the Health Insurance Portability and Accountability Act of 1996, in adult patients with an adjudicated pharmacy claim for tafamidis (tafamidis free acid 61-mg capsule once daily or tafamidis meglumine four 20-mg capsules once daily) between May 1, 2019, and June 30, 2021. Gaps in therapy were measured using day gaps between prescription refills and continuous measure of medication gaps. Implementation adherence was assessed through modified medication possession ratio (MPRm), medication refill adherence (MRA), and proportion of days covered (PDC). Patients were grouped based on Medicare coverage. Patients were analyzed by subgroups based on age and at the zip code level, via distressed communities index quartiles and rural-urban tiers. RESULTS: A total of 3,558 patients who received a prescription fill of a tafamidis formulation were identified using Medicare Fee-for-Service (FFS) and Medicare Advantage (MA) claims data from May 1, 2019, to June 30, 2021. The characteristics of this patient population were consistent with published literature, as 98.6% were older than 65 years, 53.4% were between 75 years and 84 years, and 81.5% were male. In the patient population receiving tafamidis refills, adherence was high across all 3 measures, with mean MPRm greater than 90% and mean MRA greater than 80%, across all age groups. Mean PDC adherence rates were 79% or more across all age groups. Concomitant medications were generally indicated for heart failure and thrombosis. Among monotherapy groups with similar demographic makeup, adherence was significantly higher among users of tafamidis free acid vs tafamidis meglumine (P < 0.0001 across all mean adherence measures). CONCLUSIONS: Our results demonstrate that real-world adherence to tafamidis in the Medicare population is high, regardless of age, zip code-level socioeconomic quartile, or geography. Adherence was higher among patients receiving tafamidis free acid, suggesting that the enhanced convenience of a single capsule once daily may positively contribute to adherence among patients with ATTR-CM. DISCLOSURES: Darrin Benjumea is an employee of Genesis Research who has been contracted by Pfizer, Inc., for involvement in this study. Andrew Peterson is an employee of University of the Sciences who has been contracted by Pfizer, Inc., for involvement in this study. Zach Bredl is an employee of Care Journey who has been contracted by Pfizer, Inc., for involvement in this study. Anuja Roy, Nick Marchant, Jose Alvir, Rahul Bhambri, Jason Kemner, and Bhash Parasuraman are employees of Pfizer, Inc., and own stock and/or stock options. This study was supported by Pfizer, Inc.

Temporal Trends in Diagnostic Testing Patterns for Wild-Type Transthyretin Amyloid Cardiomyopathy in the Medicare Fee-for-Service Population.

Wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM) is frequently misdiagnosed or diagnosed late in the disease course. ATTRwt-CM can be diagnosed invasively through tissue biopsy, but current diagnostic recommendations indicate technetium-99m pyrophosphate (99mTc-PYP) bone scintigraphy is an acceptable noninvasive alternative. The relative use of these confirmatory diagnostic tests in routine clinical practice is unknown. A retrospective observational study assessed temporal trends in biopsy and 99mTc-PYP scintigraphy and differences in patient characteristics using in/outpatient claims data from the US Medicare fee-for-service database. Claims prevalence for biopsy alone (≥1 claim for cardiac/extracardiac biopsy), imaging alone (≥1 claim for 99mTc-PYP scintigraphy), and both tests and patient demographic, geographic, and clinical characteristics were examined. Of patients (n = 1226) receiving an ATTRwt-CM diagnostic code, 29%, 47%, and 24% were diagnosed by biopsy alone, 99mTc-PYP scintigraphy alone, and both tests, respectively. Patients with claims for 99mTc-PYP scintigraphy alone were older than those with claims for biopsy alone (79.9 vs 76.5; p <0.001). Fewer patients in the southern United States and more patients in the northeastern United States had claims for 99mTc-PYP scintigraphy alone than biopsy alone (p <0.001). There was a temporal trend toward more claims for 99mTc-PYP scintigraphy alone (odds ratio 1.21; p <0.001) and both tests (odds ratio 1.10; p = 0.008) versus biopsy alone. From 2017 to 2019, claims increased for 99mTc-PYP scintigraphy alone. In conclusion, these data suggest a growing preference for the noninvasive imaging technique, which has high sensitivity/specificity, usability, and accessibility and may help facilitate earlier disease diagnosis. United States regional differences in the use of 99mTc-PYP scintigraphy highlight the need for education initiatives.

A review of the pharmacoeconomics of eletriptan for the acute treatment of migraine.

Migraine is a commonly occurring, chronic disorder that can cause significant disability. Eletriptan, a selective serotonin 5-hydroxytryptamine 1 receptor subtype B/D (5-HT1B/1D) agonist, is a clinically effective treatment for moderate to severe migraine. The objective of this literature review was to summarize the available data on the pharmacoeconomics of eletriptan relative to other triptans. Articles meeting the following three criteria were included in the review: 1) contained pharmacoeconomic data on a marketed dose of eletriptan; 2) included data on at least one other comparator triptan; and 3) was in English. A MEDLINE(®) search yielded a total of eight studies (from the European Union [n=5] and from the USA [n=3]) across multiple regions. Seven of the studies examined the pharmacoeconomics of eletriptan relative to other triptans, and a further study examined the health care costs of eletriptan 40 mg versus sumatriptan 100 mg. Eletriptan 40 mg was among a group of triptans, including rizatriptan 10 mg and almotriptan 12.5 mg, demonstrating the greatest cost-effectiveness. This result held across different definitions of efficacy (2 hours pain-free, sustained pain-free, and sustained pain-free with no adverse events) and also held when cost-effectiveness models accounted for second doses and use of rescue medication, management of adverse events, and productivity loss, in addition to drug acquisition costs. Only limited head-to-head comparator data were available. The majority of pharmacoeconomic studies utilized the same set of efficacy and/or tolerability data, and indirect costs were rarely included despite the fact that the majority of per capita migraine costs are attributable to indirect costs. In summary, although the market is now dominated by generics, eletriptan 40 mg is among the most clinically and cost-effective oral triptans available for the management of acute migraine. Increased effectiveness/efficacy of eletriptan may necessitate a lesser need for other migraine treatments and/or switching to other triptans.