Developing a biosimilar is a far more nuanced and complex process than developing a generic drug.1 Biosimilars, like all biologics, are produced through an intricate, multistep process, using living cells. Moreover, the cell line and manufacturing process of the reference product are proprietary and belong only to the original manufacturer. Biosimilarity for antibodies can only be established through evaluation of the biosimilar in active comparator clinical trials and experiments with the reference product.2 Procurement and analysis of multiple batches of the reference product establish a baseline to inform subsequent structural, and functional, biosimilarity tests.3
References: 1. Mellstedt H, Niederwieser D, Ludwig H. The challenge of biosimilars. Ann Oncol. 2008;19:411-419. 2. US Food and Drug Administration. Guidance for Industry: Scientific Considerations in Demonstrating Biosimilarity to a Reference Product. www.fda.gov/downloads/drugs/guidances/ucm291128.pdf. Accessed December 21, 2018. 3. McCamish M, Woollett G. The state of the art in the development of biosimilars. Clin Pharmacol Ther. 2012;91:405-417. 4. Lee JF, Litten JB, Grampp G. Comparability and biosimilarity: considerations for the healthcare provider. Curr Med Res Opin. 2012;28:1053-1058.