Table 1.

Differences Between Generic Drugs and Biosimilars

	Generic Drugs (A=A)	Biosimilars (A ≠ )
Production	Chemical synthesis	Complex biological process in cell lines in specialized production facilities
Sensitivity to production process change7	Less sensitive	Sensitive
Reproducibility7	Easy to establish	Difficult to establish
Interchangeability	Regulatory agencies generally designate the two as interchangeable	Due to their complexity and impurity profiles, interchangeability of biologics or biosimilars could have clinical consequences and repeated switches may increase immunogenicity
Substitution	Depending on local rules, pharmacists may be authorized or even required to substitute a generic for the original without informing the prescribing physician (automatic substitution)	Biosimilar status by regulator does not imply interchangeability