The results of an interesting study of infliximab biosimilar use at a Veterans Administration (VA) facility were announced at the Academy of Managed Care Pharmacy’s Nexus 2020 session. The paper outlined real-world experience that further bolsters support for biosimilar infliximab switching.
The poster did not indicate industry support for the research. It detailed changes in coverage over time and subsequent uptake of the two marketed biosimilar versions of Remicade®. Before May 2017, the reference agent was considered the preferred infliximab agent on the VA National Formulary. After that date, the VA decided to make Inflectra® (Celltrion/Pfizer’s infliximab-dyyb) the preferred product. This policy was changed in September 2018, when Renflexis® (infliximab-abda) was designated the preferred infliximab agent.
Derek K. Pinnell, PharmD, and colleagues from the VA Medical Center in Salt Lake City noted that 10 months after the first policy change, Inflectra utilization rose above 50% of total infliximab prescriptions. However, Renflexis garnered more than 50% utilization only two months after being named preferred product. The reduced delay (and subsequent > 85% total utilization of Renflexis) was considered a consequence of “increasing familiarity and comfort with biosimilars in general,” stated the authors. They were quicker to institute biosimilar infliximab switches after that most recent policy change.
Unsurprisingly, fewer patients who were already established on treatment with the reference biologic switched to Inflectra than patients who were treatment naïve after the biosimilar was designated the preferred agent. There was more than a 20-point difference between infliximab-naïve use of Remicade and those who were already receiving it (65%) after the first policy change. This difference rapidly dropped once Renflexis was named preferred product (just 20% remained on the reference product at the end of the study period in December 2019).
It does seem that VA physicians were far quicker to switch to another biosimilar once the second policy change was implemented. This applied even to physicians with patients already receiving Remicade.
The study offers a glimpse of what can also occur in other health systems and provider networks. As contracting or pricing deals change over time for medications like infliximab, payers can be expected to change preferred status on one or more of the drugs in the category. It appears that physicians, at least in the VA system, are willing to roll with the changes.