Pharmacokinetic and Pharmacodynamic Comparison of Fluticasone Propionate/Formoterol Fumarate Administered via a Pressurized Metered-Dose Inhaler and a Novel Breath-Actuated Inhaler in Healthy Volunteers

Introduction: Fluticasone propionate/formoterol fumarate (fluticasone/formoterol) exposures, following administration of Flutiform® K-haler®, a breath-actuated inhaler (BAI), were compared with the Flutiform pressurized metered-dose inhaler (pMDI) with/without spacer in two healthy volunteer studies. In addition, formoterol-induced systemic pharmacodynamic (PD) effects were examined in the second study. Methods: Study 1: single-dose, three-period, crossover pharmacokinetic (PK) study with oral charcoal administration. Fluticasone/formoterol 250/10 μg was administered via BAI, pMDI, or pMDI with spacer (pMDI+S). Pulmonary exposure for BAI was deemed no less than for pMDI (primary comparator) if the lower limit of 94.12% confidence intervals (CIs) for BAI:pMDI maximum plasma concentration (Cmax) and area under the plasma concentration-time curve (AUCt) ratios was ≥80%. Study 2: two-stage adaptive design, both stages being single-dose, crossover without charcoal administration. The PK stage compared fluticasone/formoterol 250/10 μg via BAI, pMDI, or pMDI+S. The primary comparisons were as follows: BAI versus pMDI+S for fluticasone and BAI versus pMDI for formoterol. Systemic safety with BAI was deemed no worse than primary comparator if the upper limit of 94.12% CIs for Cmax and AUCt ratios was ≤125%. PD assessment was to be conducted if BAI safety was not confirmed in the PK stage. Based on PK results, only formoterol PD effects were evaluated. The PD stage compared fluticasone/formoterol 1500/60 μg via BAI, pMDI, or pMDI+S; fluticasone/formoterol 500/20 μg pMDI; and formoterol 60 μg pMDI. The primary endpoint was maximum reduction in serum potassium within 4 hours postdose. Equivalence was defined as 95% CIs for BAI versus pMDI+S and pMDI ratios within 0.5-2.0. Results: Study 1: lower limit of 94.12% CIs for BAI:pMDI ratios >80%. Study 2, PK stage: upper limit of 94.12% CIs for fluticasone (BAI:pMDI+S) ratios <125%; upper limit of 94.12% CIs for formoterol (BAI:pMDI) ratios >125% (for Cmax, not AUCt). Study 2, PD stage: 95% CIs for serum potassium ratios 0.7-1.3 (BAI:pMDI+S) and 0.4-1.5 (BAI:pMDI). Conclusions: Fluticasone/formoterol BAI performance was within the range observed for the pMDI with/without a spacer. Sponsor: Mundipharma Research Ltd. EudraCT 2012-003728-19 (Study 1) and 2013-000045-39 (Study 2).