The Flexibility Papers No. 3: Old Drugs, New Possibilities – Repurposing as Part of the Rare Disease Framework November 6, 2026 By James E. Valentine & Sarah Wicks —

https://www.thefdalawblog.com/2026/11/the-flexibility-papers-no-3-old-drugs-new-possibilities-repurposing-as-part-of-the-rare-disease-framework/?utm_source=rss&utm_medium=rss&utm_campaign=the-flexibility-papers-no-3-old-drugs-new-possibilities-repurposing-as-part-of-the-rare-disease-framework In the first installment of The Flexibility Papers, we proposed a different starting point for rare disease drug development: rather than beginning with a conventional development program and asking what departures might be justified, FDA and sponsors should begin with the disease, the product, and the available evidence to identify a fit-for-purpose pathway. Our second installment considered how patient perspectives should meaningfully inform that process. This post takes up another part of the same question: What should development look like when the drug is not new, but its proposed use is?