Apremilast and narrowband ultraviolet B combination therapy suppresses Th17 axis and promotes melanogenesis in vitiligo skin: a randomized, split-body, pilot study in skin types IV–VI

Improved repigmentation of generalized vitiligo in skin types IV–VI has been reported in clinical response to combined therapy with apremilast and narrowband (NB)-UVB; however, tissue responses to combined therapy versus NB-UVB monotherapy have not been elucidated. We compared the change from baseline in cellular and molecular markers in vitiligo skin after combined therapy versus NB-UVB monotherapy. We assessed lesional and nonlesional skin samples from enrolled subjects and evaluated for immune infiltrates, inflammatory, and melanogenesis-related markers which were compared across different treatment groups. Combined therapy resulted in significant reduction of CD8 + T cells and CD11c + dendritic cells, downregulation of PDE4B and Th17-related markers, and upregulation of melanogenesis markers. This study was limited to small sample size, skin types IV–VI, and high dropout rate. Our molecular findings support the clinical analysis that apremilast may potentiate NB-UVB in repigmentation of generalized vitiligo in skin types IV–VI.