A New Supporter

Initially, The American College of Rheumatology urged caution around the use of biosimilars. Information about the manufacturing process for a branded biologic is proprietary; a biosimilar manufacturer will not have access to the details of the process so how could they guarantee their product would be the same? It is now well accepted by the scientific community that biosimilars are safe, and in February 2018 ACR published a white paper, The Science Behind Biosimilars – Entering a New Era of Biologic Therapy (1), which aims to educate ACR members about and support the use of biosimilars.

“Increased real-world experience with biosimilars in Europe, new data including a prospective switching study (NOR-SWITCH), and increasing clarity around FDA policies (naming, switching) have all served to increase confidence in biosimilars,” explains Doug White, one of the authors of the paper and ACR Board of Directors member at large.

The paper explains that a biosimilar and its reference product must have identical amino acid sequences and must be ‘highly similar… notwithstanding minor differences in clinically inactive components’ in many analytical assays. “The biosimilar must be equivalent to its reference product in clinical trials assessing pharmacokinetics/pharmacodynamics and clinical efficacy and must have comparable safety and immunogenicity to its reference product,” says Jonathan Kay, Professor of Medicine and Timothy S. and Elaine L. Peterson Chair in Rheumatology at the University of Massachusetts Medical School in Worcester, and another author of the paper. “Thus, any differences in manufacturing processes between an approved biosimilar and its reference product do not result in ‘clinically meaningful differences’. Patients receiving treatment with an approved biosimilar should not experience any difference in response than that which would be expected when using another lot of the branded reference product.”

Despite the fact that biosimilars are safe and effective, uptake in the US has been slow. According to Angus Worthing, a doctor with Arthritis and Rheumatism Associates and chairman of the American College of Rheumatology’s Government Affairs Committee, “Only two of the six FDA-approved biosimilars for rheumatologic diseases are available; the biggest obstacle is patent disputes and manufacturer decisions that prevent their use. One important long-term barrier is insurance coverage. Ironically, despite being priced 15-30 percent lower than reference products, we’re seeing some biosimilars kept off formularies.”

This appears to be a result of the US drug distribution system in which medication formularies are dictated by interactions between pharmacy benefits managers (PBMs) and manufacturers. The larger the rebate or price concession paid by manufacturers to PBMs, the more likely a drug will be on formulary, and a lower-priced drug may result in a lower rebate payment. “Biosimilars may be kept off formularies precisely because they are less expensive! This is paradoxical and may prevent biosimilars from realizing their promise of lower prices and increased access to treatment,” says Worthing.

To help patients get better access to biosimilars, Worthing would like to see the FDA quickly finalize its interchangeability approval pathway so that manufacturers can perform clinical trials to demonstrate safety and efficacy of alternating back and forth between reference products and biosimilars. In addition, he believes it would be beneficial for Congress to reform the drug distribution system to create more transparency in the rebate system. Boosting the supply of biosimilars – including interchangeable biosimilars – and improving incentives to bring them onto formularies should improve access to biosimilars and help lower biologic drug prices.