When a biosimilar has also been designated “interchangeable” by the FDA, pharmacists can switch a product without first checking in with the prescribing physician. Only one adalimumab biosimilar, adalimumab-adbm (Cytezlo), has gone through the additional studies required by the FDA to achieve interchangeability status.3
Currently, 47 states allow substitutions of “interchangeable” biosimilars, although pharmacists must send a change notification to the clinician within a certain time frame after they make the switch. At present, 40 states require the pharmacist notify the patient before they substitute an interchangeable biosimilar—thus, at the time the drug is dispensed.4 The FDA is currently reviewing adalimumab-afzb (Abrilada) for interchangeability status, and experts expect that adalimumab-atto (Amjevita) and adalimumab-bwwd (Hadlima) will also attempt to achieve it.3
Dr. Nola notes that interchangeability status may influence the inclusion of certain biosimilars over others in each payer’s formulary. However, even for non-interchangeable products, insurance companies may effectively force a change for patients by deciding which reference biologic and biosimilar products they will cover.
Financial Impact
One of the main draws of biosimilars is their potential to provide cost savings to the medical system, some of which would hopefully be passed on to patients. Biosimilars are less expensive to develop than their reference products because much of the basic science was established during development of the reference product. Theoretically, this should allow for less expensive biosimilar products on the market, which should also push down the cost of the reference biologic.
In Europe, the introduction of adalimumab biosimilars has resulted in steep price discounts and increased patient use. When infliximab-dyyb (Inflectra) first launched, its list price was only 10% less than that of infliximab (Remicade) in the U.S. However, after four years, the price for both the biosimilar and for infliximab itself has dropped by 50%.5
Due to the complexities and contradictions embedded in the U.S. healthcare market, it’s unclear if similar drops will be seen for adalimumab biosimilars, which are handled differently from infusion products in terms of insurance coverage. Although adalimumab-atto (Amjevita) was introduced at 55% of the current wholesale price of adalimumab (Humira), its list price is only 5% below the current adalimumab list price.3
Some analysts speculate that AbbVie is likely to increase its rebates to PBMs to remain competitive with the adalimumab biosimilars and retain its preferred status on most formularies. By increasing its PBM rebates a relatively small amount, it may be able to match the net cost of biosimilar manufacturers, who also must pay AbbVie royalties. If this is the case, adalimumab biosimilars may not gain traction in the market and prices may not decline.6
