What are biosimilars?
Since Erythropoiesis Stimulating Agents are complex proteins with side chains, not every molecule is identical to each other, and therefore it is impossible to develop a “generic” version that is identical to the originator molecule.
For biologic drugs whose patents have expired, the FDA has developed an approval pathway for biosimilar agents whose safety, efficacy, and potency is sufficiently similar to the originator molecule that it can be used as a therapeutic alternative.
The advantage of biosimilar agents is that they are expected to be 20% to 30% less expensive than the originator molecule.
Biosimilar ESAs have been used successfully in Europe since 2008, and at least two biosimilar ESAs are under development in the United States as of 2016.
A biosimilars is a copy of a biologic (bio-originator) made by a different manufacturer from the original innovator of the biologic agent that is no longer protected by patent.
The manufacturer does not have access to the originator’s molecular clone or the exact fermentation and purification process.
The biosimilars have undergone rigorous assessment in comparison to its reference product and have been approved by a regulatory agency (e.g., FDA). It is estimated that the cost of biosimilars will be 80% of the original product and lead to cost savings.
Direct comparison of the biosimilar with the bio-originator shows that efficacy and side effects are similar.
There is a concern that the biosimilar may potentially cause immunogenicity problems if there is frequent switching among the biosimilars.
Presently several biosimilars of TNF inhibitors have been FDA-approved. These include ETN-szzs (Erelzi), ETN-ykro (Eticovo), INF-dyyb (Inflectra), INF-abda (Renflexis), INF-qbtx (Ixifi), ADA-atto (Amjevita), ADA-abdm (Cyltezo), and ADA-adaz (Hyrimoz). Other biosimilars for other biologics are in development.
