Extrapolation of data is an established scientific and regulatory principle that has been used for many years.2 The FDA acknowledges and accepts extrapolation and carefully weighs the evidence before granting approval to other indications.1,2
Extrapolation of efficacy and safety data to other indications may be possible if3-5:
Biosimilarity has been clinically confirmed in a key indication.
There is a shared mechanism of action for approved indications of the reference product.
Rationale for extrapolation of indications
When a drug is “highly similar” and the mechanism of action is the same across disease states, extrapolation of indica-tions is justified and may be approved by the FDA.2
Extrapolation is not made from one indication to another
Extrapolation is not made from one clinical experi-ence to another, nor does it assume that if a drug works in one indication, it also works in another. Rather, a shared mechanism of action between indi-cations supports confirmation.3,4
Extrapolation allows confidence in biosimilars for approved indications4,5
References: 1. Stevenson JG. Clinical data and regulatory issues of biosimilar products. Am J Manag Care. 2015;21(16):S320-S330. 2. US Department of Health and Human Services. Scientific considerations in demonstrating biosimilarity to a reference product. Washington, DC: US Dept of Health and Human Services; April 2015. 3. US Food and Drug Administration. Christl L. Overview of the regulatory pathway and FDA’s guidance for the development and approval of biosimilar products in the US. 4. Weise M, Bielsky M-C, De Smet K, et al. Biosimilars: what clinicians should know. Blood. 2012;120(26):5111-5117. 5. McCamish M, Woollett G. The state of the art in the development of biosimilars. Clin Pharmacol Ther. 2012;91:405-417.