Developers can expect the FDA to demand costly clinical trials to verify that a biosimilar is effectively identical with a reference product.
The FDA will “almost certainly require clinical data in order to demonstrate interchangeability,” a legal standard that permits pharmacists to switch a biosimilar for its reference product without physician approval, predicts law firm Goodwin Procter.
Although the FDA has yet to establish a specific regulatory framework for determining biosimilar interchangeability, agency officials have “indicated that [mandatory clinical trials] is a very real possibility,” according to “Biosimilars: A Guide to Regulatory and Intellectual Property Issues,” a Goodwin Procter report.
The FDA has said it is in the process of crafting guidance on how to meet the legal burden of interchangeability, although it has given no timetable on its release.
Requiring clinical trials to establish interchangeability could prove both time-consuming and expensive, the report says, a prospect that may “erode the incentives for pursuing a biosimilar pathway in the first place.”
As an example, the report highlights an earlier prediction from Pfizer subsidiary Hospira that trial costs could range from $70 million to $250 million per drug, which would ensure a “far smaller” interchangeability market.
The report cites the European biosimilars market as an example of why interchangeability determinations are important, attributing the “relatively slow uptake” of biosimilars there in part due to the absence of drug substitution laws.