Drug survival of apremilast in a real-world setting.

Apremilast is a novel oral phosphodiesterase-4 inhibitor approved for treatment of plaque psoriasis and psoriatic arthritis in Japan in December 2016. We have treated a substantial number of patients with psoriasis with apremilast and investigated the length of the treatment period with apremilast (drug survival of apremilast) in 138 patients with psoriasis who were treated at the Department of Dermatology in Jichi Medical University Hospital from 1 March 2017 to 31 August 2018 using the Kaplan-Meier survival curve. The drug survival rate of apremilast at 1 year was 53.4%. The median length of the drug survival period was 453 days. There were no statistical differences in the drug survival rate in terms of the type of psoriasis, previous systemic treatment or presence of one or more adverse events. Drug efficacy was investigated in 115 patients who were followed for more than 16 weeks. There was no correlation between drug efficacy and sex, previous systemic treatment or presence of one or more adverse events; however, there was a correlation between drug efficacy and plaque size (P < 0.01, rs = -0.29). The result of our study indicates that apremilast is effective regardless of the history of prior systemic treatment, and it supports our previous finding that small plaque-type psoriasis is more sensitive to treatment with apremilast.