according to an analysis published in . The increased prices raise concern “because they demonstrate that the approval of new therapies did not ameliorate and could have even contributed to high inflation rates observed for incumbent drugs,” wrote the authors.
Four self-administered disease-modifying therapies (DMTs) for multiple sclerosis (MS) were available before 2009, and seven new branded DMTs were introduced after that year. Previous research indicated that the prices of DMTs for MS increased at higher rates than the prices of drugs for other disorders. How these price increases affected pharmaceutical spending during the past decade is uncertain, however.
A review of Medicare claims data
, a fellow in pharmacoeconomics, outcomes, and pharmacoanalytics research at the University of Pittsburgh, and colleagues examined claims data from 2006 to 2016 from a 5% random sample of Medicare beneficiaries. Information for a mean of 2.8 million Medicare beneficiaries per year was available. The researchers extracted all prescription claims for self-administered DMTs for MS (that is, glatiramer acetate, interferon beta-1a, interferon beta-1b, fingolimod, teriflunomide, dimethyl fumarate, and peginterferon beta-1a).
Dr. San-Juan-Rodriguez and associates chose three main outcomes. The first was the annual cost of treatment with each medication, which was based on Medicare Part D prescription claims gross costs and Food and Drug Administration–approved recommended dosing. The second was the market share of each medication, which the researchers defined as the proportion of pharmaceutical spending accounted for by each drug. The third was pharmaceutical spending per 1,000 Medicare beneficiaries for all drugs. The investigators also examined the relative contributions of Medicare Part D Plans’ payments, patients’ out-of-pocket costs, and other payments toward pharmaceutical spending.
Prices defied market expectations
The annual costs of treatment with self-administered DMTs for MS increased more than 300%. The mean annual cost was $18,660 in 2006 and $75,847 in 2016, and the mean annual rate of price increase was 12.8%. “Prices of most self-administered DMTs for MS increased in parallel, defying standard market expectations,” the investigators wrote.
Branded formulations of glatiramer acetate maintained the largest market share throughout the study period, ranging between 32.2% and 48.4%. However, the market share of platform therapies – glatiramer acetate, interferon beta-1a, and interferon beta-1b – decreased significantly from 2006 to 2016. Market shares for brand-name glatiramers declined from 36.7% to 32.2%, for intramuscular interferon beta-1a (30 mcg) from 32.3% to 14.2%, for interferon beta-1b from 18.7% to 4.5%, and for interferon beta-1a (8.8, 22, or 44 mcg) from 12.2% to 8.3%. The market shares of newer therapies, however, increased to 7.9% for fingolimod, 9.0% for teriflunomide, and 19.2% for dimethyl fumarate.
Pharmaceutical spending per 1,000 beneficiaries increased by a factor of 10.2 throughout the study period (from $7,794 to $79,411). Patients’ out-of-pocket spending per 1,000 beneficiaries increased by a factor of 7.2 (from $372 to $2,673). Furthermore, the relative contribution of federal payments toward pharmaceutical spending increased from 68.5% to 73.8%.
“Large increases in drug prices have not been specific to MS drugs,” said Dr. San-Juan-Rodriguez in an interview. “We previously described similar trends in other specialty medications used to treat severe disease states, such as tumor necrosis factor inhibitors [TNFi] for the treatment of rheumatoid arthritis. Yet these increases took place at a slower pace. For instance, list prices of TNFi increased at an average annual rate of 9.9% in the same time period, 2006-2016.
“It is important to acknowledge that rising list prices of drugs may partially reflect competition for rebates,” he added. “Yet the specific reasons behind the faster growth of prices of MS drugs, compared with the prices of drugs used in other disease states, remain uncertain.”
Neurologists should bear in mind that, although generic drugs are substantially cheaper than branded drugs, generic specialty medications do not always reduce costs for Medicare Part D beneficiaries. “On the contrary, due to incentive misalignments created by the Medicare Part D benefit design, beneficiaries using generic drugs such as Glatopa ... may pay more than those using the branded drug,” Dr. San-Juan-Rodriguez said.