Biologics and Biosimilar Drug Products: Pharmacist Guide to Patients’ Frequently Asked Questions
On July 29, 2021, the Food and Drug Administration (FDA) approved the first interchangeable biosimilar insulin product, Semglee (insulin glargine-yfgn), which may prompt questions from patients. This resource provides pharmacists with answers to patients’ most common questions about biological drug products (biologics), biosimilars, and interchangeable biosimilars in patient-friendly language.
What is a biologic?
- Biologics are generally large, complex molecules made from living cells, rather than created through chemical processes like most small-molecule drugs. Hormone therapies, vaccines, and blood products are examples of biologics.
- Biologics can be used to treat cancer, rheumatoid arthritis, inflammatory bowel disease, multiple sclerosis, psoriasis, diabetes, and more.
- Unlike most medications, biologics are not absorbed well when taken by mouth. They are often given as an injection or as an infusion in a hospital or infusion center.
What is a biosimilar?
- Biosimilars are biologics that are considered highly similar compared to an existing biologic, also known as the reference product. A biosimilar is the same as its reference product in:
- Dosage form
- Route the medication is given (e.g., by mouth, by injection, etc.)
- Treatment benefits
- Possible side effects
- Biosimilars have similarities with generic medications, but there are key distinctions between them. A generic medication contains the same active compound as and is essentially identical to a brand-name drug. In contrast, it is not possible to create an exact copy of a biologic due to its large size, complexity, and natural variability. This means that while biosimilars can share the same or close to the same qualities as an already-approved biologic, they do not contain identical active ingredients. Minor differences in inactive components are also allowed.
- There can be multiple biosimilar products for the same reference product.
Are biosimilars always interchangeable with the biologic reference product?
- No. A biosimilar is interchangeable only if:
- It produces the same clinical outcome as the biologic reference product in any given patient.
- Data establishes that, if administered more than once, switching between the biosimilar and the biologic reference product does not pose a greater risk than using the reference product only.
- As opposed to biosimilars that are not interchangeable, FDA allows pharmacists to substitute an interchangeable product for its biologic reference product without consulting the prescriber; however, state law must give pharmacists that authority.
- The first FDA approval of an interchangeable biosimilar occurred in July 2021 for Semglee (insulin glargine-yfgn), which is interchangeable with and can be substituted for its biologic reference product Lantus (insulin glargine) for the treatment of diabetes mellitus.
- Biologic: A biologic is generally a large, complex molecule made from living cells, rather than created through chemical processes like most small-molecule drugs.
- Biosimilar: A biosimilar is a biologic that is considered highly similar compared to an existing biologic, also known as the reference product. There can be multiple biosimilar products for the same reference product.
- Interchangeable biosimilar: An interchangeable biosimilar produces the same clinical outcome as the biologic reference product in any given patient.
Are biosimilars the same as generic drugs?
- No. Although there are a few similarities, biosimilars and generic drugs have distinct differences, as shown in the diagram below.
Generic Drug Products
- Small, simple molecules
- Synthetic, chemically produced
- Identical active ingredient
- Less intensive approval process than biosimilars
- Absorbed and available at same rate and extent as original product
- Pharmacists can substitute a generic without consulting the prescriber
Biosimilar Drug Products
- Large, complex components
- Natural, biologically active sources
- Similar but not identical active ingredient
- More intensive approval process than generics
- Not necessarily absorbed or available at same rate or extent as reference product
- Pharmacists can ONLY substitute a biosimilar without consulting the prescriber IF it is approved as an interchangeable product, subject to state pharmacy laws
- As safe and effective as the original product
- May be more affordable
Can pharmacists dispense a biosimilar instead of a prescribed biologic?
- Pharmacists can ONLY substitute a biosimilar for a biologic reference product without consulting the prescriber IF it is approved as an interchangeable product and allowed by state pharmacy laws and regulations.
Are biosimilars more affordable than biologic reference products?
- Maybe! Biologics can be expensive due to the complex processes required to develop them. Because biosimilars can avoid repeating the costly clinical trials of their reference products, they may be more affordable.
- Advise the patient to check with their insurance provider or refer to their insurance policy’s formulary of covered medications to find out if their insurance plan covers a biologic and/or its biosimilar alternatives
What are ways to learn more?
- Encourage the patient to discuss with their prescriber or pharmacist whether the medication they have been prescribed is a biologic and if biosimilars are available.