Development issues related todesigns in neuropathic pain in light of the European MedicinesAgency’s (EMA) Guideline for the treatment of pain

In this paper, we review certain aspects of the new guideline on the clinical development of medicinal products intended for the treatment of pain of the European Medicines Agency, which came into effect July 2017. The content the new guideline seems to be especially of value for the development of oral or parenteral analgesics, and is less relevant for topical formulations, which increasingly are recognized as important new therapeutic modalities for neuropathic pain. The guideline discusses the importance of targeting the population, and points out that new, innovative development designs are welcomed. We will present aspects of such designs. Cross-over studies, enrichment and withdrawal designs are discussed, and for the development of a topical analgesic, the latter study designs are better fit to capture clear efficacy versus placebo. For repurposing of old drugs in the field of pain, consultation with competent authorities (national or centrally via EMA) is advised, to discuss in depth what is required to obtain a marketing authorization for an old repositioned drug on a case-bycase basis.