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With biosimilars, close counts
WASHINGTON, D.C.—The adage says that "close only counts in horseshoes and hand grenades," and the same measure will now be applied to biosimilars. But how close is close enough?
In the first glimpse of regulators' thinking on the subject, Dr. Janet Woodcock, director of the U.S. Food and Drug Administration's (FDA)Center for Drug Evaluation and Research, and her co-authors write in the New England Journal of Medicine that the approval for biosimilars will require a new paradigm of sponsor-FDA interactions involving analysis of much more data than traditional generics.
Although typically more structurally complex than the small-molecule drugs more prevalent in today's market, biologics vary in complexity from cellular therapies to small, highly purified proteins.
"Unfortunately, access to such products may be limited, not infrequently because of their cost," the authors state.
To improve access, Congress passed the Biologics Price Competition and Innovation (BPCI) Act of 2009, authorizing the FDA to oversee an "abbreviated pathway" for approval of biologics that are "biosimilar" to already-approved products. Utilizing knowledge from the reference products, the abbreviated pathway will eliminate unnecessary testing of biosimilars in animals and humans.
By way of comparison, in 2009, almost 75 percent of small-molecule prescriptions dispensed in the United States were for generics, and the approval of a generic drug resulted in average savings of 77 percent of the product's cost within the first year. Although cost reductions for biosimilars probably won't be as large, the Federal Trade Commission predicts that their availability will significantly reduce biologics' cost and increase their accessibility, Woodcock and her colleagues say.
"Given the complex nature of biologics, it's unlikely that a 'one-size-fits-all' systematic assessment of biosimilarity can be developed. Instead, FDA scientists plan to integrate various types of information to provide an overall assessment that a biologic is biosimilar to an approved reference product. Such a 'totality of the evidence' approach can also be applied to assessing biosimilars, since it seems possible to exceed a current state-of-the-art analytic characterization by evaluating more attributes and combinations of attributes at greater sensitivities with multiple complementary methods. There may be strategies that allow a 'fingerprint'-like identification of very similar patterns in two different products. This may involve new technologies or improvements in current technologies. The methodology may also vary depending on the complexity of the biological product being evaluated. Although additional animal and clinical studies will generally be needed for protein biosimilars for the foreseeable future, the scope and extent of such studies may be reduced further if more extensive fingerprint-like characterization is used," the authors state.
Drugmakers are keenly interested in the process being mapped out by the FDA, and the agency is currently considering how interactions with companies might be structured and how they will affect the user-fee program that Congress has mandated for biosimilars. As required by the Biologics Price Competition and Innovation Act, the FDA is consulting with public and biosimilars industry stakeholders in developing recommendations for a biosimilars user-fee program for fiscal years 2013 through 2017.
"At the outset of the FDA-biosimilars industry stakeholder meetings, FDA and industry stakeholders agreed to a set of 'ground rules' governing our discussions," Woodcock tells ddn. "Under the ground rules, the participants will not discuss with external parties the issues under discussion in the FDA-industry stakeholder meetings. The purpose of these ground rules is to promote open and constructive discussions; in FDA's view, this approach is necessary to produce the best set of proposed recommendations for a biosimilar user fee program. Accordingly, FDA cannot respond to your inquiry. However, following the conclusion of the public and industry stakeholder meetings, FDA will publish the proposed recommendations in the Federal Register for public comment. After consideration of such public views and comments, FDA will revise the recommendations as necessary before transmitting them to Congress."
As is true of other aspects of pharmaceutical development, the advent of a vigorous market for biosimilars will take time. Under the U.S. healthcare law passed last year, brand-name biologic drugs were granted a 12-year period of market exclusivity before generic versions can be sold. The market is expected to grow from $243 million in 2010 to $3.7 billion by 2015, according to a report from market analysis firm Datamonitor.