Topical calcipotriol combined with phototherapy for psoriasis : The results of two randomized trials and a review of the literature

Background: Calcipotrial has a well-documented effect in the treatment of psoriasis. Objective: To confirm the beneficial effect of the combination of calcipotriol and UVB and to demonstrate that the combination is safe and well tolerated. Methods: Data from two randomized right/left studies were analysed. Patients included in the studies had chronic stable plaque-type psoriasis with symmetrical lesions on the arms, the legs and/or the trunk. In one study, 101 patients were treated with calcipotriol on one side and calcipotriol + UVB on the other side of the body (open study). In the other study, 77 patients were treated with calcipotriol + UVB on one side and vehicle + UVB on the other side of the body (double-blind study). Calcipotriol ointment, 50 μg/g, was applied twice daily and UVB 3 times weekly for 8 weeks. UVB was increased from 0.7 MED before treatment in rapid steps up to the erythema threshold. Result: In both treatment series the therapeutic effect of the combination of calcipotriol and UVB was enhanced as compared to calcipotriol alone and UVB alone. In the first series there was a significant reduction of the psoriasis area and severity index (PASI) with the combination after 2 weeks as compared to calcipotriol alone. At the end of treatment significantly more sides were cleared after calcipotriol + UVB than after calcipotriol alone. In the other series there was a significantly faster onset of improvement on the sides treated with calcipotriol + UVB than on those treated with vehicle + UVB. After 2 weeks there was a significant difference in PASI in favour of calcipotriol + UVB. At the end of treatment, however, there was no difference between the treatments. There was a similar adverse event profile with either treatment. The addition of UVB to calcipotriol did not alter the tolerability or safety of topically applied calcipotriol. Conclusions: The result indicates a beneficial effect of combining calcipotriol and phototherapy. The findings are compared to other published studies.