Written By: Angus Worthing MD
In case you missed it, a new kind of medicine recently arrived in rheumatology clinic: the biosimilar.

What exactly is a biosimilar?

Well, you may know what biologics are – highly complex medicines made in living cell mixtures that are given as injections or infusions for autoimmune diseases like rheumatoid arthritis, psoriatic arthritis and lupus, and other conditions. Many of the drugs administered at ARISE are biologics. Think of biosimilars as a little like a “generic” version of biologic drugs. The difference between a generic and a biosmilar is that a generic contains the exact same active ingredient as its brand name drug, whereas a biosimilar is proven to be highly similar to its brand name biologic, yet can have slight differences that do not have an affect on the way the drug works. Slight differences are expected due to the large size and complexity of biologic drugs.

Because biologics are more complex compared to regular “small molecule” medicines (such as pills), the Food and Drug Administration (FDA) requires much more rigorous analysis before approving biosimilars compared to generic drugs. The FDA has approved 9 biosimilars as of this writing (March 2018), but due to patent disputes and manufacturer decisions, only 3 of them are available. Two are biosimilars to Remicade (Inflectra and Renflexis) and the third is an oncology drug (Zarxio). Each biosimilar is administered in the same way, in the same dose and frequency as its brand name biologic. Biosimilars appear to be quite safe and effective based on rigorous data from the FDA approval process, as well as numerous clinical studies, and also experiences from other countries where biosimilars have already been used for several years. It is hoped that biosimilars will help lower the high cost of prescription drugs and improve access to breakthrough treatments in the U.S.

Find out more about biosimilars at the FDA, or my blog at the American College of Rheumatology’s SimpleTasks site here.