Drug development in dermatology: challenges in treating young patients.

Introduction: Drug development for skin disorders is influenced by the concept of children as 'therapeutic orphans' and is subject to pediatric requirements of the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA). The EMA requires a 'pediatric investigation plan' (PIP) early in development. Healthy newborns' skin is as thick as that of adults. For crisaborole for atopic dermatitis, the FDA accepted pivotal trials involving patients 2-79 years; the EMA accepted this as part of its PIP. In contrast, for psoriasis, PIPs require separate evidence of efficacy and safety in children aged 6-17 years.

Areas covered: Adolescents' skin does not change overnight on their 18th birthday, only the legal status. Most FDA pediatric requirements are grounded in commonsense and reflect current scientific understanding. The EMA, however, continues to take rigid stance in its pediatric demands. PIP negotiations are often lengthy, complex, and frustrating.

Expert opinion: Companies must possess a deep understanding of the clinical landscape, considerable patience, and sometimes seek external experts' support. A gap has become wider between US and EU, with the EU increasingly falling behind in drug development.