Combination TL01 ultraviolet B phototherapy and topical calcipotriol for psoriasis: a prospective randomized placebo-controlled clinical trial.

Background: Previous studies have demonstrated the ultraviolet (UV)-sparing effect of combining topical calcipotriol with broadband UVB in the treatment of psoriasis.
Objectives: To determine if the combination of narrowband TL01 UVB phototherapy and topical calcipotriol produces the same UVB-sparing effect.
Methods: This was a randomized, placebo-controlled, blinded clinical trial. Fifty psoriasis patients were recruited, 25 of whom were randomized into the active group who received TL01 phototherapy together with twice-daily application of calcipotriol cream 50 microg g(-1). The control group received TL01 phototherapy and twice-daily application of a topical emollient as placebo. TL01 phototherapy was given three times per week starting at 70% minimal erythema dose with 20% increments as tolerated for up to approximately 20 sessions. Patients were assessed using the Psoriasis Area and Severity Index (PASI) and Psoriasis Disability Index (PDI). They were evaluated at treatment sessions 8, 14 and 20, and followed up at 5 and 10 weeks post-treatment. Statistical analysis was performed using a two-tailed t-test.
Results: There were no significant differences in demographic characteristics and baseline PASI and PDI scores between the two groups. The mean PASI score declined significantly (P < 0.01) for both groups after treatment. The difference in mean PASI score reduction from baseline between the two groups was only significant during the first eight sessions, with a net reduction of 3.6 (95% confidence interval 1.0-6.2, P = 0.008) in the active group relative to the control group. The mean PDI score declined significantly (P < 0.05) for both groups, but there was no statistical difference in mean PDI score reduction between the two groups (P = 0.8) at the end of treatment. The mean cumulative UVB dose for the active group was significantly lower (P < 0.02) at 16 204 mJ cm-2 compared with 21 082 mJ cm-2 for the control group.
Conclusions: We conclude that combining TL01 phototherapy with topical calcipotriol cream has a UVB-sparing effect.