Efficacy and safety of apremilast and its impact on serum cytokine levels in patients with Behçet's disease.

To evaluate the long-term clinical efficacy of apremilast in Behçet's disease (BD) and its effect on serum cytokine levels. This study included 15 BD patients who were treated with apremilast. The rates of change in oral and genital ulcers, skin lesions, arthritis, and arthralgia were evaluated every 3 months for 12 months. The efficacy of apremilast was compared between patients with and without oral ulcer remission. Changes in the serum levels of interferon-gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), interleukin (IL)-10, IL-17A, IL-6, IL-8, and IL-23 between baseline and 3 months after apremilast initiation were compared. After 3 months, oral and genital ulcers disappeared in most cases. The skin and joint lesions tended to improve for up to 6 months; however, recurrence was observed after 9 months. The improvement of genital ulcers was earlier in the oral ulcer remission group than the oral ulcer non-remission group, with the genital ulcers disappearing within the first 3 months. The baseline levels of serum cytokines, analyzed in seven patients, did not exhibit significant associations with specific organ lesions. After administration of apremilast, the TNF-α and IL-23 levels significantly decreased; however, the IFN-γ, IL-6, IL-8, and IL-10 levels did not show significant changes. The rates of decrease in the serum IL-6, IFN-γ, and IL-10 levels were greater in patients with improved oral ulcers. Modulation of serum cytokine levels with apremilast might underlie the efficacy of apremilast in oral ulcers in BD patients.