ABSTRACT
For an approved biosimilar product, it is a common practice that the provider (pharmacist or insurance company) may switch from the innovator product to the approved biosimilar product based on factors unrelated to clinical/medical considerations. In practice, it is a concern that this non-medical switch may present unreasonable risk (e.g., reduced efficacy or increase of the incidence rate of adverse events) to patients with the diseases under study. In recent years, several observational studies and a national clinical study (NOR-SWITCH) were conducted to evaluate the risk of a non-medical switch from a reference product to an approved biosimilar product. The conclusions from these studies, however, may be biased and hence misleading due to the lack of some scientific and/or statistical deficiencies in the design and analysis of the data collected. In this chapter, valid study designs and appropriate statistical methods are recommended for a more accurate and reliable assessment of the potential risk of medical/non-medical switch between a proposed biosimilar product and a reference product. The results can be easily extended for evaluation of the potential risk of medical/non-medical switch among multiple biosimilar products and a reference product.
