Drug development is looking at the over-activity of phosphodiesterase 4 (PDE4) and the regulation of cyclic AMP levels in the inflammatory response as targets for new AD therapies.7

Crisabarole ointment, marketed by Pfizer as Eucrisa, received US FDA approval in 2016 for mild to moderate AD. In addition to PDE4 blocking effects, it also inhibits tumour necrosing factor TNF-α, interleukins and other cytokines.21,22

Benefits cited for crisaborole are that it lacks side effects commonly associated with topical steroids, being less immunosuppressant and having no effect on skin thinning. It may also reduce itching.23 As at July 2017, the European Medicines Agency had yet to determine any EU market authorisation.24

Dumipilab, a recombinant human IgG4 monoclonal antibody which inhibits interleukin signalling, may receive EMA approval sooner. Regeneron and Sanofi UK announced this summer they were one step nearer gaining market authorisation for dumipulab injection (Dupixent) following a positive opinion from the EMA's Committee for Medicinal Products for Human Use.25