Biosimilars vs. Generics
Exploring the differences between biosimilars and generics.
Biosimilars and generics are both versions of FDA-approved treatments that are more affordable than the reference product due to abbreviated approval processes.1 However, there are certain key differences to distinguish between the two.2
Molecular differences

Generics are relatively small, simple molecules that are derived from inorganic sources and manufactured to be exact replicas of the original drug. By contrast, biosimilars are large and complex molecules, often proteins, that are derived from living sources.2 Discover more about what biosimilars are here.
Cost of biosimilars vs. generic drugs

The chemical structure of a generic is identical to the original drug. This means that less testing is required for approval, making them around 80% cheaper than the reference product.3,4 The development timeline for a generic drug is typically only around 2-3 years.5
Although biosimilars are not chemically identical to the reference product, they can still offer price reductions of up to 30%. Biosimilars are more costly than generics due to the longer and more complex development process and the greater totality of evidence required for FDA approval.6,7 These stringent regulatory testing requirements mean that it can take around 7-8 years to bring a biosimilar to market.5
Key differences between biosimilar and generic drugs2,3,5-7,9-11


- FDA. https://www.fda.gov/drugs/biosimilars/biosimilar-and-interchangeable-products#generic. Published 2017. Accessed May 5, 2021.
- Thill M, et al. Biosimilars: what the oncologist should know. Future Oncol. 2019;15(10):1147-1165.
- FDA. https://www.fda.gov/media/83670/download. Accessed May 5, 2021.
- CTCA. https://www.cancercenter.com/community/blog/2018/12/whats-the-difference-biosimilar-and-generic-drugs. Published 2018. Accessed May 5, 2021.
- mAbxience. https://www.mabxience.com/products/biosimilar/generics-biologics-biosimilars-whos-who. Revised 2021. Accessed May 5, 2021.
- Bhatt V. Current market and regulatory landscape of biosimilars. Am J Manag Care. 2018;24(21 Suppl):S451‒S456.
- Janjigian YY, et al. Talking to patients about biosimilars. Future Oncol. 2018;14(23):2403-2414.
- FDA. https://www.fda.gov/consumers/consumer-updates/generic-drugs-undergo-rigorous-fda-scrutiny. Published 2014. Accessed May 5, 2021.
- Halimi V, et al. Clinical and regulatory concerns of biosimilars: A review of literature. Int J Environ Res Public Health. 2020;17(16):5800.
- US Pharmacist. https://www.uspharmacist.com/article/biosimilars-not-simply-generics. Published 2019. Accessed May 5, 2021.
- FDA. https://www.fda.gov/drugs/biosimilars/biosimilar-development-review-and-approval. Published 2017. Accessed June 10, 2021.