The results of a systematic review support the interchangeability of biosimilar tumor necrosis factorα (TNF)-α inhibitors with their respective reference biologics in treating rheumatoid arthritis, inflammatory bowel disease, and psoriasis (Chingcuanco F, et al. Ann Intern Med. 2016 Aug 2. Epub ahead of print).
According to the lead investigator of the study, G. Caleb Alexander, Associate Professor of Epidemiology and Medicine, Johns Hopkins Bloomberg School of Public Health and Center for Drug Safety and Effectiveness, Baltimore, MD, these findings may have a significant impact on healthcare systems at a time when many of these biologics are coming off patent, and cheaper biosimilar versions are becoming available.
Biologics are the fastest growing sector of the pharmaceutical market. For payers, however, the growth of the biologics market has presented new challenges, as they seek to preserve access to cutting-edge medicines in the face of increasing budgetary pressures. By competing with original biologic agents, biosimilars offer more choices, which can benefit patients and save healthcare systems money. “The billion-dollar question has been whether these ‘generic biologics’ are the same as the brand-name versions,” said Dr Alexander. “The same debate occurred with the advent of less complicated generic drugs and now it’s being hashed out all over again with much more at stake—more room for error and more potential for cost savings to the health system.”
The investigators looked at 19 studies directly comparing original and biosimilar forms of anti–TNF-α therapies. These studies included 8 phase 1 randomized trials, 5 phase 3 randomized trials involving patients with rheumatoid arthritis, and 6 observational studies involving patients with rheumatoid arthritis or inflammatory bowel disease. They found that all phase 1 trials showed pharmacokinetic parameters of the biosimilars and respective biologics to be within the prespecified equivalence margin of 80% to 125%. In the phase 3 trials, achievement of the primary clinical end points was comparable between the biosimilars and reference biologics. The researchers also found that most treatment-emergent adverse events were mild to moderate in severity and there were no notable differences in the type or prevalence between groups. Two cross-sectional observational studies showed cross-reactivity between products, whereas 4 cohort studies of patients who were switched from reference to biosimilar products suggested similar efficacy and safety outcomes.
“These findings are big news, because TNF-α inhibitors are a costly and commonly used class of biologics and it hasn’t been clear whether they are as safe and effective as their branded counterparts,” Dr Alexander said. “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,” he concluded, adding that further research is needed to determine whether these findings hold true for other types of biosimilars.