How Is A Biosimilar Different From A Biologic?

Biosimilars Have a Place, But They're Not Equivalent To Biologics

Biologic Molecule
A comparison of a biologic molecule and aspirin shows that a biologic is an extremely complex structure. A biologic can't be recreated like a small molecule medication can because a biologic is created inside a living cell, not a test tube. Image © Janssen Biotech, Inc.

What Is A Biologic?

A biologic is a type of medication that is created inside a living cell. Scientists create biologic medications by changing the DNA inside certain cells. The cells are changed so that they are programmed to replicate indefinitely. Once the cells are able to replicate themselves, they are also altered so that they are programmed to create the antibody that the scientists want. In the case of some biologic drugs used to treat inflammatory bowel disease (IBD), the antibodies created are those that work against tumor-necrosis factor (TNF).

The biologic medications that are used to treat IBD are Humira (adalimumab), Cimzia (certolizumab pegol), Remicade (infliximab), Tysabri (natalizumab), Simponi (golimumab), and Entyvio (vedolizumab). All of these biologic medications are called innovative products, and are manufactured only by the companies that developed them. Innovative products, in the pharmaceutical industry, are new products that are not available from another company, and may be under patent. They are created in a controlled, engineered environment, which is very different than chemically-derived medications. 

Some of the biologic medications created for IBD are TNF inhibitors. People with IBD often have higher levels of TNF in their bodies than people without IBD, which is why the TNF is thought to be a part of why the inflammation associated with IBD continues and affects the digestive tract. The anti-TNF medications work by blocking TNF and preventing it from causing inflammation. Entyvio is a gut-homing α4β7 integrin antagonist that works by stopping the white blood cells, which are thought to contribute to inflammation, from taking hold inside the digestive tract.

Biologic medications are used to treat more conditions than IBD, they are also used to treat other auto-immune or immune-mediated diseases such as rheumatoid arthritis, psoriasis, ankylosing spondylitis, and hidradenitis suppurativa.

Are Biosimilars Like Generics?

Biosimilars are often described as the "generic" of biologic medications. However, this is not really an accurate way of describing a biosimilar. When we go into a drugstore, we often have a choice of buying the name-brand of a drug, and a bioequivalent drug — a generic. If you look at the packaging on both medications, you'll see the active ingredients are the same.  

In order for a company to market a generic, the FDA must agree that the generic is interchangeable with the innovative product. This doesn't mean that a generic is exactly the same, however. There could still be differences in the inactive ingredients, but the active ingredient is, according to the FDA, the same.

A biosimilar is licensed by the FDA and must be the same as a biologic in its:

  • Mechanism of action 
  • Administration route (such as infusion or injection)
  • Dosage
  • Strength

A biosimilar is not equivalent to a biologic, however, and certain differences are allowed. The design and creation of a biologic drug is complicated enough that a biosimilar isn't going to be precisely the same as a biologic. Because we don't have much scientific data yet, experts are in disagreement over whether a biosimilar will work exactly the same way the biologic does. 

During a Janssen-hosted conference on the science behind biologics, Michael Yang, President of Immunology at Janssen Biotech said "biologics are living proteins, and living proteins can't be copied." Because a biologic product is grown inside a specific type of cell, it's not something that can be recreated. A biosimilar will be different from a biologic, in the same way that, as Yang explains, one oak tree is different from another, even though they are both classified as oak trees.

What Can IBD Patients Do?

As more biosimilar products come to market, there will be more medication choices available to people with Crohn's disease and ulcerative colitis. Patients receiving biologic drugs or biosimilar drugs should familiarize themselves with the laws in their state regarding biologics and biosimilars.

Before receiving an infusion at an infusion center or a hospital, patients can also ask to ensure that they are receiving the exact medication that their physician has prescribed, "as written." A biosimilar should have a different brand name than a biologic, so reading the label on the medication is important. If your state does not have a law, or the law is not strong enough, contact your local representatives to ensure they know your views, as a patient affected by these laws.

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