July 12 and 13 hearings of the FDA’s Arthritis Advisory Committee cleared the way for two new biosimilars, adalimumab and etanercerpt. The committee unanimously supported manufacturers’ applications for the drugs – but that wasn’t the only point of consensus. Participants and even committee members expressed concerns about unfinished regulatory policy and the need to prioritize patient safety.
A particular topic of concern was non-medical switching. Madelaine Feldman, MD, a rheumatologist and member of the Alliance for Patient Access, described patients who were stable on a biologic and then required to switch to a different treatment because of health plans’ financial negotiations. As Dr. Feldman explained it, “The physician can write for any medication they want. The insurance company just won’t pay for it.”
Dr. Feldman urged the FDA to halt non-medical switching “until the appropriate switching studies have been performed and the biosimilar meets interchangeability criteria.” A number of speakers during the meeting’s public portion also expressed concerns about forced switching to biosimilars based on cost alone.
[WATCH: Understanding Non-Medical Switching]
Post-market Surveillance & Indication Extrapolation
The issue of post-market surveillance also captured the group’s attention.
As David Margolis, professor at the University of Pennsylvania School of Medicine, reportedly noted, “I find it shocking that we’re still relying on passive systems to track adverse events.” Dr. Margolis reiterated these concerns in the following day’s hearing on an etanercept biosimilar, noting that post-marketing studies were necessary to gauge the impact of indication extrapolation and the treatments’ long-term safety.
Extrapolation occurs when the FDA approves a biosimilar to treat a disease state without comprehensive testing for that disease state. Both the impact of biological treatments on patients’ immune systems and the range of conditions that a single biosimilar can be approved to treat necessitate particular caution in extrapolating indications.
As the Alliance for Patient Access explained in a letter to the FDA prior to the July 12 hearing, “The fact that a biosimilar has been tested for some indications of an innovator product is a good indicator of the drug’s safety and efficacy. But that should not automatically qualify a biosimilar for additional indications of its reference product.”
AfPA and other patient advocacy organizations have urged the FDA to include the clinical trials data from the actual biosimilar in the drug’s prescribing information. The FDA has not yet finalized its guidance on prescribing information or on biosimilar naming.