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Published on: July 11, 2013
A New Phototherapy Regimen Coupled with Oral Vitamin D Supplementation, for the Long-Term Control of Atopic
Catherine Droitcourt1,2, Sébastien Barbarot3, Valérie Visseiche4
1Department of Dermatology, CHU Rennes, Pontchaillou Hospital, 2 Rue Henri le Guilloux, 35000, Rennes, France. catherine.droitcourt@chu-rennes.fr.
Introduction:
The global burden of atopic dermatitis (AD) will continue to rise in the coming two decades, underscoring the need for affordable and globally accessible therapies given restricted access to high-cost medications in many regions. The study aimed to evaluate the efficacy of a novel phototherapy-based regimen as an add-on therapy, together with vitamin D supplementation, on long-term disease control in AD.
Methods:
The PRADA trial combined two independent randomizations within the same population: an open-label, crossover comparison of narrowband ultraviolet B (NB-UVB) phototherapy versus observation, and a double-blind, parallel-group comparison of vitamin D versus placebo, both superimposed on standard topical anti-inflammatory treatments (TAT). It was conducted between 2015 and 2023 across 16 French hospital centers. The trial included patients aged ≥ 15 years with moderate-to-severe (IGA > 2) AD and with fewer than 100 lifetime phototherapy sessions. The primary outcome was a hierarchical composite endpoint based on: (1) repeated measures of Patient-Oriented SCORing Atopic Dermatitis (PO-SCORAD) severity score over 1 year; and (2) the cumulative use of TAT from October to March.
Results:
A total of 53 participants were allocated to the vitamin D (26 received NB-UVB during the first period), and 57 to the placebo (27 received NB-UVB during the first period). A total of 93 participants were available for the main analysis for the primary endpoint. Vitamin D was significantly associated with lower PO-SCORAD scores compared with placebo (mean [95% CI] difference -5.6 [-12.1 to -1.78]), however, this effect size remained below the prespecified minimum clinically important difference (nine points). NB-UVB showed no significant effect on PO-SCORAD scores (mean difference: 1.25 [-3.90 to 1.40]). Adverse event incidence was 0.33 per 100 patient-months, mainly nonserious photosensitivity reactions (n = 38).
Conclusions:
In the PRADA trial (underpowered due to a recruitment short fall), NB-UVB phototherapy showed no clinically meaningful benefit on the long-term control of moderate-to-severe AD. The observed benefit of vitamin D supplementation on PO-SCORAD, although statistically significant, did not reach the threshold for clinical relevance.
Trial Registration:
ClinicalTrials.gov Identifier: NCT02537509.
