DMARDs to Treat Medicare Beneficiaries with Rheumatoid Arthritis

Washington, DC—Results of a recent study suggest that the choice of biologic disease-modifying antirheumatic drugs (DMARDs) for patients with rheumatoid arthritis (RA) who receive care through Medicare may be influenced by subsidy status rather than clinical factors that balance risks and benefits as well as patient preference.

Conducted by investigators from the University of California, San Francisco, the study examined the potential impact of cost sharing for Medicare beneficiaries. The authors compared drug utilization and out-of-pocket (OOP) costs for biologic and nonbiologic DMARDs for patients with RA who reach the coverage gap (or donut hole) in Part D to patients with RA who are eligible for low-income subsidy (LIS) with reduced cost sharing.

Under Part D, patients pay 100% of drug costs when the cost of their drugs reaches $2700 through $6514. This is considered the coverage gap period, or donut hole. Prior to and after these amounts, Medicare picks up the majority of the expense.

The need to see how the design of Part D affects utilization of DMARDs for RA in Medicare beneficiaries is important given the high cost of these drugs, particularly injectable biologics. Jinoos Yazdany, MD, MPH, a co-investigator of the study who presented the results at the ACR meeting, emphasized that there are no generic treatments with the biologic agents and that all RA patients on DMARDs will reach the donut hole when taking these drugs.

Using data from a 5% random sample of Medicare fee-for-service claims for 2009 linked to Part D prescription drug files, the study included 5808 patients who were ≥65 years of age, had ≥2 face-to-face encounters for RA, were continuously enrolled in a Part D drug plan, and had ≥1 DMARD prescription. The mean age of the patients was 76 years, 82% were female, 85% were white, 97% had received any nonbiologic DMARD, and 11% had received any biologic DMARD.

Of the 5808 patients, 1414 (24%) received the low-income subsidy whereby their OOP costs were reduced and not affected when reaching the donut hole, unlike the 70% of other Medicare beneficiaries who were responsible for covering the cost of the drugs during the coverage gap.

The study compared the mean annual RA drug OOP costs per patient in those using biologic DMARDS (with or without nonbiologic DMARDs) with those using only nonbiologic DMARDs. It also compared patients who had no, partial, or full coverage during the gap phase with patients who were eligible for a LIS.

Of the patients, 679 (12%) used biologic DMARDs and 5129 (88%) used nonbiologic DMARDs. In addition, 44% of patients who used biologic DMARDs received a LIS compared with 22% of nonbiologic DMARD users.

The OOP annual costs for biologic DMARDs were low for the patients eligible for a LIS ($26) compared with the unsubsidized patients OOP annual costs ($3009); this was similarly true for nonbiologic DMARD use between the 2 groups ($11 vs $85, respectively). The largest OOP cost was incurred for the biologic DMARDs during the coverage gap, which totaled about $2347 for unsubsidized beneficiaries.

The study also looked at biologic DMARD use as covered by Medicare Part D and Part B and found that most nonsubsidized patients received their biologics through Part B.

Significantly more beneficiaries enrolled in a LIS program received biologic DMARDs compared with those who used nonbiologic DMARDs. Although more work is needed to know whether the low rates of use of the biologic DMARDs among unsubsidized beneficiaries is a consequence of substantial cost sharing, Dr. Yazdany advocated for a more coherent coverage of the biologics. She also emphasized the importance of balancing short-term costs of newer drugs with long-term costs to society, and the need for medical necessity to drive treatment decisions.