On March 19 and 20th the University of Washington School of Pharmacy hosted “The Biosimilars Conference”. This conference prompted some interesting discussions. A good background of the current legal status and issues around biosimilars can be found in the September 30th blog “Biosimilars; an Introduction”.
When talking about biologics it is important to remember that the process is the product, this is a very different concept from the small molecule world. A biologic expressed in a different host could have a slightly different amino acid sequence. With this in mind, the EU has a defined pathway for approval of biosimilar products, thus providing the US an opportunity to evaluate lessons learned. The main messages from the EU are; generic standards do not apply to biologics, two biologics can be similar but not identical, any differences must be justified, the greater the difference the more clinical data will be required, efficacy must be equivalent, safety must be similar and not worse, the immunogenic potential must be similar, there will be non-clinical and clinical requirements and there are often post-marketing commitments. The key is in the identification of the critical issues and what impact the similarities or differences have on these critical issues. This burden falls to the developer of the biologic to define. How similar or dissimilar is acceptable from a safety and efficacy standpoint?
The EU has approved six applications as biosimilar products, rejected one application (interferon alpha 2a) and three applications were withdrawn by the applicant (soluble insulin, isophane insulin and biphasic insulin).