Possible Impact of Biosimilar Infliximab on U.S. Market in Prescriptions, Pricing

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The use of biosimilars for rheuma­tology in the U.S. became a reality when the U.S. Food and Drug Administration (FDA) approved Inflectra (infliximab-dyyb), a biosimilar to Remicade (infliximab), in April. What this may mean is increased competition among drug companies with regard to pricing and, therefore, potentially lower costs for U.S. patients, according to Seoyoung C. Kim, MD, ScD, MSCE, Brigham and Women’s Hospital, Boston.

Dr. Kim is the lead author of “Utilization of the first biosimilar infliximab since its approval in South Korea,” which appeared in Arthritis & Rheumatology in May 2016. The study demonstrated that the introduction of biosimilar infliximab in South Korea led to a significant increase in prescriptions for the new drug, as well as decreases in the price of the brand-name reference drug.¹

Aside from pricing considerations, inherent concerns exist with introducing a new class of drug to market, not the least of which is clinical efficacy and safety. The FDA’s potential fast-track approval process means that practicing rheumatologists will soon have another drug in their arsenal against rheumatic disease, and likely many more to follow.

Background

The FDA defines a biosimilar as “a biological product that is approved based on a showing that it is highly similar to an FDA-approved biological product, known as a reference product, and has no clinically meaningful differences in terms of safety and effectiveness from the reference product.”²

Congress passed the Biologics Price Competition and Innovation Act, part of the Affordable Care Act, in 2009 in an attempt to slow upward trends in the price of biologic medications and to encourage the availability of less expensive treatments. The legislation effectively created the potential for a faster approval pathway for products that are biosimilar to or interchangeable with an FDA-licensed reference product. The FDA also published The Purple Book, an online reference that lists biologics with reference-product exclusivity, as well as the biosimilars and interchangeables (i.e., a product that is biosimilar to an FDA-approved reference product and meets additional standards for interchangeability) for each.

The FDA requires manufacturers of biosimilars to prove the drug is as safe and effective as the reference drug for approval. To date, there are few long-term studies to support the clinical safety and efficacy of biosimilar drugs for rheumatic disease, according to Dr. Kim, but more research is being published on the subject. One study showed the safety and efficacy of CT-P13, a biosimilar to Remicade, among European patients with inflammatory bowel disease.³ Multinational studies of CT-P13 showed comparable efficacy and safety over 54 weeks among patients with active rheumatoid arthritis and an inadequate response to methotrexate and ankylosing spondylitis.^4,5