Researchers have found that generic forms of a biologic drug used to treat inflammatory diseases such as psoriasis and rheumatoid arthritis are as safe and effective as the brand-name equivalent.
The study, by scientists at the Johns Hopkins Bloomberg School of Public Health, is titled “Bioequivalence of Biosimilar Tumor Necrosis Factor-α Inhibitors Compared With Their Reference Biologics: A Systematic Review,” and published in the Annals of Internal Medicine.
Biologic drugs are complex and large products made from living cells, and include vaccines, gene therapies, and recombinant therapeutic proteins. Another important characteristic that differentiates biologic drugs from chemically synthesized medicines is the fact that their pharmacologic activity is heavily dependent on the manufacturing process, and a simple change in this process can greatly alter the drug’s structure, making it very difficult to recreate a precise replica.
Their clinical, regulatory and commercial importance is growing. Companies argue that generic forms of biologic drugs, also known as biosimilars, are not interchangeable with established brand-name drugs, although the generic forms would be more economically viable for consumers and the health system alike.
In this review, researchers focused on the available evidence regarding bioequivalence between original drugs and biosimilars for tumor necrosis factor-α (TNF-α) inhibitors, a class of drugs frequently used to manage diseases characterized by excessive inflammation, such as psoriasis.
The researchers analysed data from 19 studies, which included Phase 1 and Phase 3 randomized clinical trials, as well as from observational studies. The available data indicate that biosimilar drugs had overall efficacy and safety outcomes “very similar” to their brand-name drugs. Researchers have, however, identified some limitations in this review, such as limited number of studies and possible publication bias.
“Our study should reassure clinicians and patients and importantly, the folks who pay the bills — insurance companies and government programs like Medicare — that biosimilar TNF-α inhibitors appear comparable to their branded counterparts based on the evidence we have thus far,” G. Caleb Alexander, MD, an associate professor and the study’s lead author, said in a press release. “Hopefully this will encourage the brisk adoption of these products. There is no question that greater competition in this market will benefit patients, prescribers and society in the long run.”
The U.S. Food and Drug Administration approved Inflectra, a biosimilar for infliximab (Remicade), for several therapeutic indications, including rheumatoid arthritis, inflammatory bowel disease, and psoriasis, in April 2016. It is the only TNF-α inhibitor biosimilar that has been approved in the U.S.
Sales for biologics are expected to represent approximately 20 percent of the total pharmaceutical market in the U.S. by 2017, the review study said.