Pilot trial: NB-UVB not enhanced by tacrolimus

May 1, 2005

New Orleans — Concomitant topical treatment with tacrolimus 0.1 percent ointment (Protopic, Fujisawa) does not improve the response of generalized vitiligo to narrowband UVB phototherapy, according to the results of a randomized, double-blind, placebo-controlled, pilot study undertaken by researchers at the University of Texas Southwestern Medical Center.

Research study To be eligible for the study, subjects had to have stable, generalized vitiligo affecting 5 percent to 50 percent body surface area with two symmetrical patches on contralateral anatomic sites measuring at least 2 cm x 2 cm and not located on the face, elbows, hands, knees or feet. The patients underwent NB-UVB therapy three times a week and had their target lesions randomized to twice daily treatment with tacrolimus ointment or petrolatum.

However, tacrolimus was not consistently favored in the between-treatment comparisons of lesion response among the individual patients, and there were no statistically significant differences in the mean percent improvement between tacrolimus and placebo at any visit.

Interpreting findings "Monotherapy with topical tacrolimus has been reported effective for repigmenting vitiligo, especially patches located on the face and neck. Hypothesizing that phenomenon might be explained by exposure of those anatomic sites to UV light and recognizing the efficacy of narrowband UVB for treatment of vitiligo, a systematic study to evaluate the potential synergism of those two modalities seemed to be the next logical step," Dr. Mehrabi says.

"Failure to find any difference between treatment groups in this investigation came as a surprise, even given our small patient population. Larger studies will have to be performed to detect a difference between the two groups.

Inclusion criteria The inclusion criteria for the pilot study allowed entry only of patients with skin phototypes III-VI, with the aim of minimizing risks of adverse events with narrowband UVB phototherapy. The patients who entered the study represented phototypes III-V.

The decision to include target lesions that were not located on the face intended to avoid confounding from incidental UV exposure. Vitiliginous patches on the elbows, hands, knees and feet were excluded recognizing that those sites are typically resistant to all treatment modalities, Dr. Mehrabi explains.

The lesions that were treated represented a variety of body sites, including the thigh, flank, abdomen, chest and extremities. At baseline, their surface area ranged from 4.3 to 33.9 cm2.

Predicting responses "With such a small number of patients who reflected a relatively diverse mix with respect to skin type and lesion location, it is impossible to make any generalizations from this study regarding factors that might predict a better response to combination treatment," Dr. Mehrabi says.

Adverse events were experienced by eight of nine patients and primarily consisted of redness, itching and burning that could be attributed to narrowband UVB phototherapy. Four patients also developed small blisters due to photosensitivity, which resolved within a few days.

Overall, the incidence of adverse events was similar for the petrolatum- and tacrolimus-treated patches. However, when patients were asked to rate the severity of their adverse events, they fairly consistently reported worse reactions on the placebo-treated side.