A multicentre open‐label study of apremilast in palmoplantar pustulosis (APLANTUS)

Background Palmoplantar pustulosis (PPP) is a chronic skin disease with painful erythematous scaly or crusty lesions and pustules on the palms and soles. Apremilast is a phosphodiesterase 4 inhibitor that has proven effective in the therapy of psoriasis, psoriatic arthritis and in oral ulcers associated with Behcet’s disease. Objective To explore the efficacy of apremilast in PPP. Methods APLANTUS was a phase 2 single‐arm multicentre study of apremilast in 21 subjects with moderate‐to‐severe PPP. Primary endpoint was the per cent change of the Palmoplantar Pustulosis Psoriasis Area and Severity Index (PPPASI) at week 20 compared to baseline. Results 20 weeks of oral treatment with apremilast in patients with moderate‐to‐severe PPP resulted in a significant decrease of the PPPASI with a median reduction of 57.1% (p