Medicare Prescription Drug Coverage and Home Use of Erythropoiesis-Stimulating Agents for MDS-Associated Anemia: A Medicare-Database Analysis.

Erythropoiesis-stimulating agents (ESAs) are a key component of chronic anemia management, particularly in lower-risk myelodysplastic syndromes (MDS). Our prior research indicates that patients (pts) with limited mobility, financial resources, and social supports are less likely to receive ESAs. ESAs administered in a physician office are covered by Medicare Part B. Qualifying MDS pts may benefit from the option of home injection, which can be reimbursed by Medicare only under the prescription drug benefit (Part D). Part D may require substantial cost sharing, particularly during the coverage gap, while pts receiving the low income subsidy (LIS) face limited out-of-pocket (OOP) cost sharing. The need for prior authorization is common in Part D plans, unlike Medicare Part B. We examined the association between patient and Part D plan characteristics and receipt of ESAs through Medicare Part D. We hypothesized that pts with lower cost sharing, poor functional status and greater financial resources would be more likely to receive ESAs covered through Part D.

Using 100% Medicare enrollment and claims data from 2005–2008, we selected beneficiaries assigned MDS diagnostic codes. The study cohort consisted of the subset of MDS pts enrolled in Medicare Parts A and B from 12 months before MDS diagnosis, and Part D enrolled from MDS diagnosis forward. Pts with Medicare Advantage (HMO enrollment) or with renal disease were excluded. Part D plan characteristics were linked to patient-level observations. Type and level of cost-sharing associated with the highest branded drug tier was used to proxy the OOP payment associated with a Part D claim for ESA. ESA use within 6 months of MDS diagnosis was identified from Part B claims and Part D event files. We used a 2-part modeling strategy, examining receipt of any ESA, and receipt of any Part D covered ESA among beneficiaries who received ESAs. The analysis was operationalized using multivariate logistic regression, with explanatory variables including measures of LIS receipt, Part D cost sharing, pt demographics, MDS risk group, and health status [Charlson Comorbidity Index (CCI), predicted poor performance status (PS)].

The cohort included 19,504 patients, with 11,480 (59%) receiving any ESAs; 1,009 (5.2%) or 9% of those receiving ESAs had at least 1 Part D claim. LIS was received by 37% of the study cohort. Mean Part D coinsurance rate for branded drugs was 28%, with a mean copay of $41. Multivariate regression results indicated that, among pts with any ESA, those with LIS were 12% more likely to receive ESAs through Part D (p<0.01). Among those without LIS, a $10 increase in copay levels was associated with a 0.5 percentage point lower probability of receiving ESAs covered through Part D (p<0.05). Increasing age and greater CCI (more comorbidities) were associated with both greater probabilities of any ESA, and receiving them through Part D. In contrast, patients with poor PS and/or residing in a nursing home were less likely to receive any ESA, but if they received ESAs they were more likely to receive them through Part D. Higher income was associated with a greater probability of Part D coverage of ESA. For patients without LIS who received ESAs through Part D, mean OOP payment per claim was $462 (median $238), and prior authorization was required for 80% of claims. For a standard claim for 60,000 units of epoetin-alfa, we calculated an OOP payment of $245 under Part D vs. $112 under Part B.

Our results indicate that relatively few MDS pts received ESAs at home through Part D. Pts were responsive to cost sharing under Part D, with LIS recipients more likely to receive ESAs covered by Part D; increased copayments were associated with reduced use of Part D-covered ESAs. OOP payments required under Part D were substantially higher than requirements under Part B. In addition, Part D use is commonly subject to prior authorization, while Part B is not, further limiting home administration. The Medicare program may need to consider changes to Part D plan incentives to improve access to therapies such as ESAs that can be administered safely at home.

Davidoff:Novartis: Research Funding; Celgene: Research Funding; National Institutes of Health: Research Funding; GlaskoSmithKline: Research Funding. Off Label Use: Erythropoiesis-Stimulating Agents (ESAs) are indicated for the treatment of anemia associated with chronic renal failure and myelosuppressive anticancer chemotherapy in solid tumors, multiple myeloma, lymphoma, and lymphocytic leukemia. The current research explores the use of ESAs as an off-label indication within patients diagnosed with myelodysplastic syndrome. Stuart:GlaskoSmithKline: Research Funding. Shenolikar:GlaskoSmithKline: Employment. Gore:Celgene Corporation: Consultancy, Research Funding.