Biosimilars vs Bioequivalents Medications: What Are These?

With a movement in asthma towards biologics drugs coming to market and as drugs come off patents there seems to be a lot of talk about biosimiliars and bioequivalents. The discussions I have experiences seem to be centered around how patients looks at "choice"

I set out doing some research to try and understand the difference between biosimilars and bioequivalents in medications and how this relates to asthma. I need to start with trying out to understand what they even are. Here is a  bit of information to help you demystify.

The difference between biosimilars and bioequivalents?

By definition, biosimilars mimic the activity and safety of the original biologics they are based on, but the original and the "copy" are not chemically identical. They are not necessarily produced in the same way, often representing a different means to a similar end.1

Bioequivalents are the  pharmaceutical equivalent of another drug. For drugs to be considered pharmaceutically equivalent, they must contain the same active ingredient or ingredients, the same amount (dose), the same route of administration, and the same strength or concentration. Pharmaceutical equivalents may differ from the original approved drug in characteristics such as shape, scoring, mechanism of action, packaging, colors, flavors, preservatives, and expiration time.2

The fun fact that I discovered is that for most medications that are taken orally,  the active ingredients are released in the gastrointestinal (GI) tract and arrive at their site of action via the systemic circulation. Blood concentrations of the active ingredients and/or their active metabolites thereby provide a marker for the concentration at the site of action and a valid measure of bioavailability.2 If two medicines are bioequivalent there is no clinically significant difference in their bioavailability.

Bioequivalence will be part of the discussion on developing a generic for it.  Bioequivalents go through rigorous studies to ensure that they are safe and meet all necessary efficacy criteria.

Omalizumab is a popular asthma biologic medication that is coming off patent in 20173 This means that there are development in the works to bring a biosimiliar to market for it. As a patient who is looking to be involved in "choice" and selection of medications. What does this mean? It means that for this specific drug must have the same  active agreement, same route of administration etc. It also means that the inactive ingredients can be different and individual response may differ. There is no guarantee that the exact same blood concentration will be achieved.4) It is always important to speak to your physician about what options are available and may work best in you particular case. An issue that I think is is on the forefront of most patients are what are the costs and if cost saving measures are available, should I take them? There are several generic inhaled medications that are currently available, that many asthmatics use. Results are highly individualized and it is best to speak with our physician about what will work best. I have tried a couple and have had mixed results. There could have been a number of factors that planned in to this.

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