Biosimilars and generic drugs are both created based off existing FDA-approved brand-name drugs. The brand name drug is called either a “reference product” or a “reference medicine,” depending on what is being produced (biosimilars are imitations of reference products; generic drugs are copies of reference medicines). The type of reference product or reference medicine determines whether it is a biosimilar or a generic.
Biosimilars are imitations of reference products called “biologics,” which are made up of living cells. Generics are copies of reference medicines that are composed of chemicals. A drug cannot have both a biosimilar and a generic; there can only be one or the other.
Producing a biosimilar is more challenging than producing a generic drug because the reference product is made up of living cells, which are very sensitive to their environments and cannot be recreated by a chemical formula. Manufacturers create their own unique process to create an identical outcome to the existing drug. Because the makeup of biologics (the reference product) is very complex, it is hard to create imitations. Monoclonal antibodies and vaccines are some examples of biologics.
Developing a generic drug is more like following a recipe with standard ingredients. Since generic drugs are chemical copies of the reference medicine, they use the same active ingredients as the original drug and work the same way.
Biosimilars vs. Generic Drugs | |
Similarities Both are versions of FDA-approved brand-name drugs | |
Differences Depending on the type of existing FDA-approved drug (whether it is made of living cells or chemicals), either a biosimilar or a generic version may be developed. A drug cannot have both a biosimilar and a generic. | |
Generic | Biosimilar |
| Created based off existing FDA-approved drugs ("reference medicines") that are chemicals. | Created based off existing FDA-approved drugs ("reference products”) that is made up of living cells. |
Developing a generic drug is similar to following a recipe with standard ingredients. Since generic drugs are chemical copies of the reference medicine, they use the same active ingredients as the original drug and work the same way.
| Manufacturers create their own unique process to create an identical outcome to the existing drug (reference product) because the reference product is made up of living cells, which are very sensitive to their environments and cannot be recreated by a chemical formula. |
| The active ingredients are the same as the reference medicine; the generic drug is an exact copy of the reference medicine. | The active ingredients are highly similar to reference products, without any clinically meaningful differences; not an exact copy of the reference product. |
| Manufacturer must show generics are bioequivalent to the brand name drug. | Manufacturer must show no clinically meaningful differences between the biosimilar and reference product in terms of safety and effectiveness. |
| FDA-approved based on matching chemical structure. | FDA-approved after clinical trials prove that the outcome of the drug matches that of the biologic it is imitating even though it looks structurally different. |
When biosimilars do become available as treatment options for pediatric blood cancer, treatment decisions may be dictated by your child's insurance company’s drug formulary. It is important to discuss all concerns about treatment options with your child's hematologist-oncologist and the pharmacist at your specialty pharmacy.
Many biosimilars are in the process of being developed and some have been approved by the FDA. For information about the drugs listed on this page, visit our cancer drug listing.
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