What Are Biosimilar Drugs?

Definition & Examples of Biosimilar Drugs

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Biosimilar drugs are highly similar versions of biologic drugs that have been approved to treat the same conditions and diseases as the original biologic. They must undergo rigorous clinical testing and government approval before they can be approved and prescribed to the general public. They are often used to treat serious conditions such as cancer, Alzheimer's disease, and HIV.

Learn more about biosimilar and biologic drugs, including how they are approved and how they could change the pharmaceutical industry.

What Are Biosimilar Drugs?

Biosimilar drugs—sometimes referred to as biogenerics—are highly similar versions of biologic medicines made from living microorganisms found in plant or animal cells.

Like generic drugs, biosimilar drugs have the same active properties as another licensed drug.

The term “generic” refers only to traditional or small molecule drugs that are bioequivalent to an already approved small molecule drug. 

Researchers and manufacturers will produce biosimilar products to mirror previously approved drugs. The Food and Drug Administration (FDA) requires that biosimilar drugs be "highly similar," including their:

  • Safety
  • Potency
  • Purity
  • Chemical identity
  • Bioactivity

A biosimilar product must have comparable levels of efficacy and safety to the original product to be approved on an accelerated timeline; the only differences allowed are in non-active ingredients or components. 

Alternate name: biogeneric drugs, biogenerics, biosimilars

How Biosimilar Drugs Work

Most biologics are very large, complex molecules or mixtures of molecules, used to treat cancer, Alzheimer's, multiple sclerosis, HIV/AIDS, and other serious conditions.

A biosimilar drug mirrors the active properties and results of a previously approved biologic. It can then be used to treat the same disease. Unlike standard generic drugs, however, biosimilars do not exactly mirror their corresponding brand-name drugs.

Biologic drugs, which are created from living organisms, are too complex to copy exactly. Instead, manufacturers of biosimilar drugs attempt to create pharmaceuticals that have a high level of similarity in their composition, efficacy, and results.

Biosimilar drugs must undergo extensive clinical trials, both to test them as treatments and to compare them to the original biologic drug that they are replicating. Unlike generic drugs, biosimilar drugs must be prescribed by name. They cannot be replaced without the approval of the prescribing physician.

Once a drug has been approved as "interchangeable" by the FDA, a pharmacist can be substituted for the prescribed biologic drug without a physician's approval.

Approval of biosimilars is expected to help reduce costs for life-saving treatments. Treatment with biologic drugs can cost patients and insurance companies anywhere between $100,000 to $300,000 a year. Estimates based on several studies suggest that an increase of biosimilar drugs into the market could save $54 billion over a 10-year period.

Notable Happenings

Though biotechnology companies have been researching biologics and developing biosimilar treatments for years, their approval in the United States is relatively recent.

Biologics Price Competition and Innovation Act

President Obama signed the Patient Protection and Affordable Care Act into law in 2010, and an abbreviated pathway to approval for biosimilars was approved as part of that legislation. Under the Biologics Price Competition and Innovation Act (BPCIA), a product can be determined to be biosimilar if data shows that it is very similar to an already-approved biologic medication. 

First Biosimilar Drug Zarxio Approved

In 2015, the FDA approved Zarxio as the first biosimilar product in the United States. Zarxio is a biosimilar to Neupogen, a medication indicated for the treatment neutropenia in cancer patients.

Since then, the FDA has approved 27 other biosimilar drugs.

Impact on the Industry

Biosimilar products are expected to continue to have a significant impact on the pharmaceutical industry in the U.S. and Europe, including:

  • Increased competition among pharmaceutical companies
  • More treatment options for patients
  • Lower cost of medication for serious diseases
  • Increased accessibility of life-saving treatments

The FDA's approval of an accelerated timeline for biosimilars signals a change in the industry and potential for severe drops in profits for pharmaceutical companies. It is an opportunity for organizations specializing in generics and biosimilars to grow their businesses rapidly.

Key Takeaways

  • Biosimilar drugs are highly similar versions of biologic drugs that have been approved to treat the same conditions and diseases as the original biologic.
  • They must undergo rigorous clinical testing and government approval before they can be approved and prescribed to the general public.
  • Biosimilar drugs are often used to treat serious conditions such as cancer, Alzheimer's disease, and HIV.
  • Approval of biosimilar drugs is expected to benefit patients by increasing treatment options and lowering costs of complex, life-saving treatments.

Article Sources

  1. U.S. Food and Drug Association. "Biosimilar and Interchangeable Products: What Does It Mean to Have “No Clinically Meaningful Differences”?" Accessed Aug. 20, 2020.

  2. U.S. Food and Drug Association. "Biosimilar and Interchangeable Products: What Does It Mean to Be “Highly Similar”?" Accessed Aug. 20, 2020.

  3. Cancer Discovery, American Association for Cancer Research. "FDA Approves First Biosimilar, Zarxio." Accessed Aug. 20, 2020.

  4. U.S. Food and Drug Association. "Biosimilar and Interchangeable Products: What Is the Difference Between a Biosimilar and an Interchangeable Product?" Accessed Aug. 20, 2020.

  5. Association for Accessible Medicines. "White Paper Part 2: Failure to Launch: Barriers to Biosimilar Market Adoption." Download "Download White Paper." Accessed Aug. 20, 2020.

  6. U.S. Food & Drug Administration. "Biosimilar Product Information." Accessed Aug. 20, 2020.