Phase III clinical study of maxacalcitol ointment in patients with palmoplantar pustulosis: A randomized, double‐blind, placebo‐controlled trial

Abstract Palmoplantar pustulosis ( PPP ) often shows resistance to treatment. Vitamin D 3 analog (VitD 3 ) has been widely used for the treatment of psoriasis, however, the efficacy and safety of topical VitD 3 treatment of PPP are not fully confirmed. Maxacalcitol topical ointment (22‐oxacalcitriol [ OCT ]) was applied twice daily for 8 weeks. Evaluation of efficacy was based on scored skin findings for three main symptoms (erythema, pustules/vesicles and keratinization/scales). The primary and secondary end‐points were the total and symptom‐specific scores of skin findings, respectively. A total of 188 patients with moderate or severe PPP were enrolled in the study and were randomized into either the OCT group ( n = 95) or placebo group ( n = 93). The total scores (mean ± standard error) of skin findings at the last observation adjusting for those on day 1 were 5.0 ± 0.20 in the OCT group and 6.9 ± 0.20 in the placebo group. There was a significant decrease in the total score of skin findings in the OCT group compared with the placebo group ( P < 0.0001). In particular, the score of pustules/vesicles drastically decreased in the OCT group. In terms of safety, the incidence of adverse reactions in the OCT and placebo groups were 11.6% and 9.7%, respectively. These results indicate that OCT is effective and highly safe in the management of PPP . Topical OCT treatment was found to show a potent action on pustules/vesicles thereby contributing to the cure of PPP .