BIOSIMILAR AND FOLLOW-ON BIOLOGICS
Biosimilar products are expected to be comparable to an approved reference product in terms of quality, safety and efficacy profile. Approval of these products should be considered based on product comparisons and demonstration of comparability to the reference product.
Biopharmaceutical products may be currently manufactured by the same manufacturer at different sites. The “FDA Guidance on comparability” protocol is used for assuring product quality of the approved product after certain changes are made in the manufacturing process (comparability assessment, see below). The quality of these products is assured by chemical analysis and/or by using a comparability clinical study protocol.
A question often raised and debated by a generic manufacturer is whether the approach of using a comparability protocol can be extrapolated and adopted for approval of biosimilar products manu-factured by a different manufacturer. The regulatory answer today is no, it cannot be used for the approval of a biosimilar product.
The requirements for approval of biosimilar products should be based on the structural complex-ity and clinical knowledge of and experience with the reference biopharmaceutical product. Products such as growth hormone and interferon, for example, have known and relatively simple chemical structures. In addition, extensive manufacturing and clinical ex-perience is available for these products. On the other hand, monoclonal antibodies are large, glycosylated proteins and clinically less experience has been obtained with them so far. Because of the varying complexity of the biotech-derived products, the requirements for the approval process should be structured on a case-by-case basis. The following information is required for product approval.
· Structural information—Primary, secondary, ter-tiary, and if relevant, quaternary structure infor-mation, including information regarding the
· glycosylation pattern, if relevant. n Manufacturing process
· Quality attributes and clinical activities
· Pharmacokinetic-Pharmacodynamic information, mechanism of drug action
· Clinical experience, efficacy and toxicity infor-mation