Biosimilar drugs appear comparable to brand-name counterparts

Generic forms of a biologic drug used to treat rheumatoid arthritis, inflammatory bowel disease and psoriasis appear to be as safe and effective as their brand-name counterparts, according to a new study published in the Annals of Internal Medicine.

The pharmacologic activity of biologics is heavily dependent on the manufacturing process, wherein small changes in the production can alter the structure of the resulting medication. Due to the large, complex structures of biologics and the variability inherent in the manufacturing process, it is impossible to create a precise replica, or “generic version,” of a biologic, which is why they are called “biosimilars.” There can even be batch-to-batch variation in products manufactured in the same facility by the same methods.

“The billion-dollar question has been whether these ‘generic biologics’ are the same as the brand-name versions,” says study leader G. Caleb Alexander, MD, an associate professor in the department of epidemiology at the Bloomberg School and co-director of the Johns Hopkins Center for Drug Safety and Effectiveness.

Alexander and Johns Hopkins Bloomberg School of Public Health researchers analyzed the scientific literature to compare original and biosimilar forms of a treatment for rheumatoid arthritis, inflammatory bowel disease and psoriasis, known as tumor necrosis factor-alpha (TNF-α) inhibitors. This class of drugs suppresses the activity of TNF, a substance in the body that can cause inflammation and lead to immune-system diseases that affect multiple organ systems and that are a major cause of disease and disability in the United States and around the world.

They took the data from 19 studies conducted through April 2016 and found that, while there weren’t a large number of studies, the available data suggests that biosimilar drugs have very similar safety and effectiveness as their branded counterparts.

“We found that biosimliar TNF-α inhibitors and their branded counterparts had similar safety and efficacy,” says Alexander. “There has been considerable uncertainty as to whether biosimilar products are as safe and effective as their referent-or originator, or branded- counterparts. Our results suggest that they at least in this case, that they are.”

The study comes at a time when many of these biologics are coming off patent and generic versions-biosimilars-could save money.

By 2017, sales for biologics are expected to represent approximately 20% of the total pharmaceutical market, according to the IMS Institute for Healthcare Informatics. Wide adoption of biosimilars could eventually save the health system billions of dollars, according to Alexander.

“This is important because these biologics represent the fastest-growing sector of pharmaceutical spending, and both patients and third-party payers are struggling to pay the bills,” Alexander says. “Hospitals and health systems have a vital role to play in facilitating the adoption of biosimilar products through the development of guidelines and clinical policies that promote their use.”

In April, FDA approved TNF-α inhibitor biosimilar Inflectra a biosimilar for infliximab, which is sold as Remicade (Janssen Biotech), for several indications including rheumatoid arthritis, inflammatory bowel disease and psoriasis.

Other branded TNF-α inhibitors on the market include Humira, Cimzia, Enbrel and Simponi, while many biosimilar versions of these products have been approved in Canada, Asia and Europe. Many new cancer drugs are also biologics, as is insulin.

Further work is needed to characterize the real-world safety and effectiveness of other biosimilar products, according to Alexander.