BH03 Response to a novel topical dithranol formulation in mild-to-moderate alopecia areata: a phase II randomized placebo-controlled trial

There have been major advances in the treatment of severe alopecia areata (AA) in recent years, but less progress in treating mild-to-moderate disease. Here, we report the results of a multicentre phase II randomized controlled trial of dithranol, formulated in a novel topical vehicle incorporating a silicon nanoparticle controlled-release mechanism, in patients with mild-to-moderate AA. Patients with patchy active AA of ≥ 6 months’ duration and a Severity of Alopecia Tool (SALT) score < 50 were randomized to 0.25%, 0.5%, 1% or 2% dithranol or placebo applied once daily for 6 months, with a follow-up visit at 8 months. The primary endpoint was ≥ 30% reduction in SALT score at 6 months, with secondary endpoints including a 60% reduction in SALT and change in quality-of-life scores (Alopecia Areata Symptom Impact Scale and Alopecia Areata-Quality of Life Index). In total, 155 patients with AA were randomized, of whom 97 had mild disease (SALT < 20) and 58 had moderate disease (SALT 20–49). Of these, 106 patients (68%) completed the treatment phase of the trial; dropouts were equally distributed across the five groups. The primary endpoint response rate in the full analysis set (n = 155) was 76% in the dithranol 1% group, compared with 37% in the placebo group (P < 0.01). A 60% reduction in SALT score was seen in 30%, 40%, 58% and 50% of patients applying dithranol 0.25%, 0.5%, 1% and 2%, respectively, compared with 19% in patients applying the placebo. Skin irritation on the scalp was common in patients applying dithranol, although in most it was mild in degree and only weakly related to the dithranol concentration. Twenty patients (16%) using dithranol withdrew from the study due to skin irritation. Irritation was more common during the early stages of treatment and by 6 months it was reported by only five patients (6%). Eleven patients (9%) using dithranol reported temporary skin discoloration. There were no serious or unexpected adverse events. The use of dithranol to treat AA was first reported in 1935. Sporadic reports of its efficacy have appeared since, but there are no previous randomized placebo-controlled trials. The results reported here indicate that a novel dithranol formulation is an effective treatment for patients with mild-to-moderate AA. The results also raise the possibility that the efficacy of dithranol in treating AA is not related to its irritancy. Further work is needed to establish the best treatment protocol. The study was sponsored and funded by Soterios Pharma.

Citation

Messenger, A., Bryden, A., Farrant, P., Gangwany, P., Gkini, M., Harries, M., ... & Fleet, D. (2025). BH03 Response to a novel topical dithranol formulation in mild-to-moderate alopecia areata: a phase II randomized placebo-controlled trial. British Journal of Dermatology, 193(Supplement_1), ljaf085-224.

DOI

10.1093/bjd/ljaf085.224

URI

https://hdl.handle.net/20.500.14709/1167

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