Biosimilars are primarily as safe as their originators, based on data from a review of current European regulatory documents. The findings were published online in the British Journal of Clinical Pharmacology.

“Biosimilars are officially approved as similar products to a biopharmaceutical originator, which often share the same International Nonproprietary Name,” wrote L.R.A. Lepelaars, MD, of Utrecht University, the Netherlands, and colleagues. However, many clinicians remain cautious about using biosimilars, particularly those in the United States, they noted. The European Medicines Agency (EMA) has filed safety data on biosimilars, but comparative effectiveness studies often are lacking, they wrote.

In this study, the researchers compared data on 25 biologic medicinal products (19 biosimilars and 6 originators). The biosimilars were authorized by the EMA between Jan. 1, 2005 and Oct. 30, 2015 (Br. J. Clin. Pharmacol. 2017 Nov 22; doi: 10.1111/bcp.13454 ).

Overall, the researchers found 55 general safety concerns, including 22 that were deemed highly clinically relevant. Another 21 were defined as medium, while 12 had low levels of clinical relevance.

Infliximab was the only active substance with more than one difference in safety concerns between the biosimilar and originator; three more general safety concerns (all of medium clinical relevance) were noted for infliximab biosimilars compared with the originator (bowel obstruction, hematologic reactions, and lack of efficacy).

For all other active substances included in the study, one difference or no difference was found in the general safety concerns between the biosimilars and originators, and none of the differences was related to immunogenicity

The researchers assessed the safety of biosimilars by comparing them with European Risk Management Plan or Summary of Product Characteristics.

The findings support the value of biosimilars based on comparable safety profiles, the researchers noted. However, “a direct comparison between biosimilars and related originators through formal postmarketing studies (observational or clinical trials) is mandatory for specific safety and effectiveness issues emerging during the products’ life cycle,” they said.

The researchers had no financial conflicts to disclose.