The pharmacodynamics, pharmacokinetics, safety and tolerability of inhaled fluticasone furoate and vilanterol administered alone or simultaneously as fluticasone furoate/vilanterol

Purpose: To investigate the potential for systemic pharmacokinetic (PK) and pharmacodynamic (PD) interactions between inhaled fluticasone furoate (FF) and vilanterol (VI) when delivered simultaneously via the ELLIPTATM dry powder inhaler (DPI). Methods: Randomized, double-blind, placebo-controlled, crossover study. Healthy subjects (n = 16) received single doses of FF (800 mcg), VI (100 mcg), FF/VI (800/100 mcg), and placebo. Endpoints measured were systemic PD (FF: serum cortisol; VI: heart rate), FF and VI plasma PK (0-48 hours), pharyngometry, inhalation and breath hold profiles and safety assessments. Results: Treatment differences [90% confidence interval (CI)] in weighted mean serum cortisol (0-24 hours) were 12.3% [4.4, 20.9] (FF/VI vs. FF) and for maximum heart rate (0-4 hours) were -1.2 bpm [-4.6, 2.1] (FF/VI vs. VI). When delivered simultaneously, FF and VI systemic exposures were slightly lower (< 20%) versus delivery of either agent alone (although this was not a formal bioequivalence study). In vitro simulation of selected inhalation profiles and modeling supported the PK and PD findings. FF/VI, FF and VI were well tolerated with an AE incidence comparable to placebo. Conclusions: These results suggest there was a slight PK interaction and no PD interactions of concern between inhaled FF and VI when delivered simultaneously via the ELLIPTA DPI in healthy subjects.