Biosimilars 101

Written by

Alissa Johnson

July 24, 2023

With new biosimilars for Humira available this year, many of you have had questions about biosimilars: what they are, how they're approved, and more . In order to answer some of the most common questions we receive, we’ve compiled answers in this post.

What is a biosimilar?

Biosimilar products are a type of biological product. Biosimilars are compared to the original reference product, so they are evaluated by the FDA and released to the market after the reference product. When proposed biosimilars are evaluated by the FDA, they are compared to the reference product to check if they are highly similar without clinical differences, including safety, potency, and purity.  

What is a biological product?

According to the Food and Drug Administration (FDA), biological products are typically large and complex molecules and often made using living materials like animal or plant cells. The first biological product on the market is considered the brand, or reference product, by the FDA.

What is the difference between a biosimilar and a generic?

Biosimilar products are different from generic drugs, although they are both versions of brand name drugs. Biosimilars are biological products that, clinically, have similar effects as the brand product but the molecules vary slightly. Generic products are the same active ingredient as the brand-name drug. Therefore, biosimilars are not considered generic drugs by the FDA since they are not the exact same molecule. For both generic and biosimilar products, they must show similar safety and effectiveness.

Are biosimilars safe?

Biosimilars also have no clinically meaningful differences from the reference product. This means you can expect the same safety and effectiveness from the biosimilar over the course of treatment as you would the reference product. Biosimilars are made from the same types of sources (e.g. living cells or microorganisms) and are just as safe and effective as their reference products.

biosimilar description

Are biosimilars interchangeable?

Not all biosimilars are interchangeable with the reference product. In order for the FDA to consider a biosimilar interchangeable with the reference product, additional requirements must be met to show they are the same, clinically, in any given patient for the same indications. Interchangeable biosimilars can be substituted at the pharmacy for the brand product, while non-interchangeable biosimilars require a new prescription from the prescriber.

How will biosimilar products help members and employer groups?

For members, biosimilars offer more options but the members may need a new prescription from their doctor when they switch to a biosimilar product. For employer groups, having competition in the market between biosimilars and the reference products creates a more competitive pricing dynamic. At SmithRx, we leverage this to source biosimilar products at the lowest net cost and pass on 100% of the savings to the employer group.


Biosimilars | FDABiological Product Definitions | FDABiosimilar Basics for Patients | FDA

Written by

Alissa Johnson

A new type of pharmacy benefits manager, SmithRx is working to reduce pharmacy costs by reimagining the traditional PBM as a Drug Acquisition Platform built on transparent modern technology that aligns with the needs of our customers.