A biosimilar is a new type of biologic drug. A biologic drug is made from living things, such as antibodies or proteins.
“A biosimilar is a biological product that is highly similar to a U.S. licensed reference biological product for which there are no clinically meaningful differences in safety, purity, or potency of the product,” as defined by the U.S. Food and Drug Administration.
A biosimilar is comparable to a generic version of a biological drug. But because making a biological drug is so complex, the process of making the biosimilar is hugely important and unique to each drug.
The FDA has created a special approval process for biosimilars so people taking them can be assured they are safe and effective. Also, once a biosimilar is approved by the FDA, it undergoes “pharmacovigilance.” This means that the manufacturer continues to monitor the safety and efficacy of the biosimilar.
Most experts expect that biosimilars will cost less than the original biologic drugs. Still, it’s not clear how much less expensive biosimilars will be. It’s hoped that lower costs will give more people access to treatment.
Two biosimilar drugs have been approved in the United States:
Zarxio (chemical name: filgrastim-sndz), a biosimilar of Neupogen (chemical name: filgrastim); it’s used to reduce the risk of infection in people being treated with chemotherapy.
Inflectra (chemical name: infliximab-dyyb), a biosimilar of Remicade; it’s used to treat rheumatoid arthritis, Crohn’s disease, and plaque psoriasis.
Two biologic drugs are used to treat breast cancer: Herceptin (chemical name: trastuzumab) and Avastin (chemical name: bevacizumab). Before a biosimilar can be marketed, the original drug’s patent must expire. In 2017, the U.S. patents will expire on both Herceptin and Avastin. The European patent on Herceptin expired in 2014. There are six biosimilars of Herceptin being studied and four biosimilars of Avastin being studied.