A panel discussion at the annual BIO convention in San Francisco on June 8th raised an important point, which is sometimes taken for granted by payer executives, providers, and patients, alike. However, it may have missed an important point as well.
Once manufacturers have received approval to market a biosimilar, it is then imperative, like any pharmaceutical manufacturer, to be able to maintain good manufacturing practices and not experience shutdowns or interruptions in the supply of drug. These agents are complex molecules, and although this generally has not been a problem in Europe with approved biosimilars, drug shortages in the US are an ongoing issue. They occur when problems arise in maintaining manufacturing quality (e.g., FDA-mandated closures while the problem is addressed), as well as necessary plant maintenance, and lack of competition to take up the slack. In the biologics area, the vaccine supply chain has been regularly cited.
Therefore, one of the key success factors, say the panel members, which included representatives from Amgen, the University of Southern California, and the University of Chicago, is to encourage adequate biosimilar competition for each applicable drug. “We want to avoid [a quality or supply chain issue], because an ‘oops’ of any kind will set back the efforts,” stated Geoffrey Eich, Executive Director for External Affairs at Amgen.
Panelists noted that having multiple biosimilar manufacturers can insure against shortages or other supply chain issues. This is certainly true with conventional small-molecule drugs. The supply of low-cost generic agents is sometimes at issue, simply because manufacturers stop production because of inadequate margins.
However, the panelists did not take the opportunity to emphasize that the solution may not be so simple as having additional manufacturers. Consider that Inflectra®, for example, is approved as a biosimilar to Remicade®, but it likely will have not been tested for equivalent clinical and safety outcomes against the next infliximab biosimilar to be approved. Technically, is it biosimilar to Inflectra? Most would say yes. But is it substitutable should the supply of Inflectra be interrupted for any reason?
Thus is the theoretical complexity of biologic manufacturing. Although the ability to switch one biosimilar for another may be borne out later by real-life switching studies, it is extremely important today to maintain an uninterupted supply chain.