Abstract
We evaluated the pharmacodynamic effects of apremilast in 69 patients who were included in biomarker subanalyses of a phase 2b study that demonstrated the long-term safety and efficacy of apremilast in Japanese adults with moderate to severe psoriasis. The association between cytokine levels and Psoriasis Area and Severity Index (PASI) improvement was evaluated using linear regression and Spearman's rank correlation coefficient analysis. At baseline, median plasma levels of interleukin (IL)-17A, IL-17F and IL-22 were elevated versus reference values for healthy individuals, whereas tumor necrosis factor-α levels were close to normal. With apremilast 30 mg b.i.d., there were significant associations between percentage change in PASI score and percentage change in IL-17A, IL-17F and IL-22 levels at week 16. Findings demonstrate that the efficacy of apremilast in psoriasis is associated with inhibition of key cytokines involved in the pathology of psoriasis.