A 12-week, open-label study designed to examine whether switching to fluticasone propionate/salmeterol (FSC) 100/50mcg maintained control of airway inflammation in asthma patients previously treated with fluticasone propionate (FP) 220mcg BID or an equivalent dose of another inhaled corticosteroid (ICS).
52 patients (mean age 36.8 yrs) on moderate dose ICS (mean dose=498mcg/day) for ≥4 weeks participated. All patients underwent bronchoalveolar lavage (BAL) and biopsy before and 12-weeks after switching to FSC 100/50mcg BID. Eosinophil percentages and inflammatory mediators (GM-CSF, IL-8, ECP, tryptase) were evaluated on BAL specimens. Eosinophils and basement membrane thickness were quantified from biopsy specimens.
Cell/MediatornBaseline on ICS (mean ± SE)Endpoint on FSC (mean ± SE)p Value*Bronchial mucosa eosinophils (cells/mm3)392715.5 ± 3593173.2 ± 7100.753BAL eosinophils (%)480.52 ± 0.140.84 ± 0.330.522Basement membrane thickness (microns)464.07 ± 0.163.97 ± 0.150.403GM-CSF (pg/mL)311.20 ± 0.182.40 ± 0.670.096IL-8 (pg/mL)3625.54 ± 5.0731.13 ± 7.370.370ECP (μg/mL)360.66 ± 0.252.45 ± 2.060.590Tryptase (μg/mL)460.15 ± 0.070.22 ± 0.090.438*
based upon Wilcoxon signed-rank testsThe switch to FSC was not associated with changes in BAL eosinophils, BAL inflammatory mediators or sub-epithelial collagen thickness on mucosal biopsies. In addition, the switch to FSC was associated with significant (p≤0.05) improvements in AM PEF, rescue albuterol use and asthma symptoms while FEV1 and PC20 were unchanged from baseline.
In patients receiving moderate doses of ICS, FSC 100/50mcg BID enabled a >50% reduction in ICS dose without altering sub-epithelial collagen thickness, eosinophil numbers in BAL or mucosal biopsies, or BAL inflammatory mediators.
Treatment with a low dose ICS and a long-acting beta-agonist appears as effective as higher dose ICS alone in controlling eosinophilic airway inflammation.
P.M. Dorinsky, Employee of GSK, Industry.