Biosimilars

With the expiration of numerous patents for blockbuster biologics between 2012 and 2019, the interest in biosimilar production, i.e., follow-on biologics, has increased. Compared to small molecules that consist of chemically identical active ingredients, biologics are vastly more complex and consist of a multitude of subspecies. Due to their heterogeneity and the high process sensitivity, originators and follow-on biosimilars will exhibit variability in specific variants over time, however the safety and clinical performance of both originator and biosimilar biopharmaceuticals must remain equivalent throughout their lifecycle. Process variations are monitored by modern analytical tools (e.g., liquid chromatography, immunoassays, mass spectrometry, etc.) and describe a unique design space for each biologic.

Thus, biosimilars require a different regulatory framework compared to small-molecule generics. Legislation in the 21st century has addressed this by recognizing an intermediate ground of testing for biosimilars. The filing pathway requires more testing than for small-molecule generics, but less testing than for registering completely new therapeutics.

In 2003, the European Medicines Agency introduced an adapted pathway for biosimilars, termed similar biological medicinal products. This pathway is based on a thorough demonstration of "comparability" of the "similar" product to an existing approved product. Within the United States, the Patient Protection and Affordable Care Act of 2010 created an abbreviated approval pathway for biological products shown to be biosimilar to, or interchangeable with, an FDA-licensed reference biological product. A major hope linked to the introduction of biosimilars is a reduction of costs to the patients and the healthcare system.