Topical maxacalcitol for the treatment of psoriasis vulgaris: a placebo-controlled, double-blind, dose-finding study with active comparator

1α, 25‐Dihydroxy‐22‐oxacalcitriol (maxacalcitol) is a vitamin D3 analogue which displays approximately 10 times greater efficacy at suppressing keratinocyte proliferation in vitro than calcipotriol and tacalcitol. To determine clinical efficacy, a phase II double‐blind, randomized, left vs. right, concentration–response study was performed with once‐daily topical maxacalcitol in patients with mild to moderate chronic plaque psoriasis. Primary efficacy parameters were psoriasis severity index (PSI) based on sum of scores for erythema, scaling and induration and investigators' overall assessment of patients' response to therapy at 8 weeks of treatment. One hundred and forty‐four patients participated. All concentrations of maxacalcitol ointment (6, 12.5, 25 and 50 μg/g) were significantly more effective at reducing PSI than placebo (P