A to Z Health Guide

Biosimilar Drugs: What You Need to Know

If you get an erythropoiesis stimulating agent (ESA) to treat anemia (low red blood cell count), then you are getting a biologic drug.  This means that the ESA was made from the building blocks of living things like plants and animals (“bio” means “life”). Biologic drugs are very complex and cost a lot to make.  This makes it hard for many people who need a biologic drug to get it.  But now, the United States Food and Drug Administration (FDA) is allowing drug companies to make biosimilar drugs.  “Similar” in the case of biosimilar drugs means that the drug should be so much like the original biologic drug that it is as safe and effective. 

Making a copy of an original biologic drug is somewhat like making a copy of a simple drug like aspirin.  But because both biologic and biosimilar drugs are made from living things, there are always some differences in each batch of either the biologic or biosimilar drug that is made.  These differences are small and should not, by law, affect drug safety or efficacy.  So, the same way you can buy a cheaper store brand of aspirin (generic drug) instead of a brand name aspirin, you can buy a cheaper biosimilar drug.  It should not be cheaper because of less quality, but because costly research on how to the make the original drug has already been done. 

Biosimilar drugs have been used for many years in Europe and other countries with success.  Problems with biosimilar drugs happened most often in countries with poor control over how the drugs were made.  But the FDA has been very careful to ensure that companies follow tough rules for making biosimilar drugs safe and effective.  Allowing biosimilar drugs in the United States has taken many years of planning by hundreds of medical experts.  

The FDA is currently reviewing two new biosimilar ESAs for use in dialysis, so if approved, you may be getting a biosimilar to treat your anemia in the near future.  Some questions you should consider asking your healthcare provider are:  

  • Are there going to be changes in my ESA medicine?  Ask your healthcare team to let you know about any planned changes in your drugs before they are made.
  • What is the name of the new medicine?  Write it down so you can update all your medicine lists at home and for your other medical providers
  • Are there any known reactions or side effects?

As with any drug, the most important thing is safety.  The safety issues that you should know about are the same as for other drugs, including original biologic drugs:

  • Possible reactions:
  • Allergic reactions and side effects:  Your body may see both biologic and biosimilar drugs as a danger and will respond with a number of signs and symptoms.  Quickly let your healthcare team know if you are not feeling well after you have been given any drug.  Watch for itching, swelling, difficulty breathing, sweating, fever, headache or muscle aches, nausea, vomiting, diarrhea, and any other changes in what you see or feel in your body.
  • Changes in the drugs you usually get, including:
  • a switch from an original biologic ESA to a biosimilar ESA
  • a switch back from a biosimilar ESA to an original biologic ESA
  • a switch from one brand of biosimilar ESA to another brand of biosimilar ESA
  • a switch from one brand of an original biologic ESA to another brand of original biologic ESA
  • Ask your healthcare team to let you know about any planned changes in your drugs before they are made.  Ask if these changes have been put in your records, along with the complete names of the drugs exchanged.  Having the correct product names makes it easy to trace where any problem may have happened.

The other important issue is how well the biosimilar ESA works.  This depends on the healthcare team closely monitoring your anemia when you start getting the biosimilar ESA.  It also depends on you letting your healthcare team know how you are feeling after any changes in your drugs.

Just like generic drugs, biosimilar drugs will allow more people to get the care they need.  As with any type of drug, however, patients and healthcare teams need to first be aware of safety.  This means stopping or fixing reactions and side effects right away.  You should always ask what drugs you are getting and why.  This is no different when it comes to biosimilar drugs.  Be sure to let your healthcare team know how you are feeling after any changes in your medication. 

Date Reviewed: 
October 6, 2016

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