Biologic disease modifying agents (bDMARDs) are an integral part of rheumatoid arthritis treatment guidelines but are associated with significant cost in the US. We present the trends in total spending and unit cost of conventional DMARDs (cDMARDs) as compared to bDMARDs in Medicare program.
We used the Medicare drug spending data for the year 2012-2017 covering all part B (fee-for-service) and part D drugs. Total spending was calculated by summing spending across various drug formulations and unit drug cost by dividing total spending by number of doses dispensed. We present the 6-year trends in total spending, total beneficiary count and unit costs of each of the commonly used cDMARDs and bDMARDs.
Between 2012 and 2017, the total spending on the cDMARDs increased 5-folds from $98 million to $579 million; this was fraction of total spending on bDMARDs which increased from $4.3 to $10.0 billion. This increase was driven largely by unit costs of drug rather than number of beneficiaries. There was a 6-fold increase in the unit cost of generic hydroxychloroquine followed by methotrexate and leflunomide. Amongst bDMARDs, adalimumab and etanercept unit cost increased by 2-folds. The increase was less pronounced for office-administered products.
Despite the availability of several generic cDMARDs over decades, there were steep increases in the unit cost of these agents to "keep pace" with the increases in bDMARDs. As the number of elderly rheumatoid arthritis patients increases, policy interventions might be required to reduce the spending on both biologics and conventional DMARDs.