Is Blood Eosinophil Count a Predictor of Response to Bronchodilators in Chronic Obstructive Pulmonary Disease? Results from Post Hoc Subgroup Analyses.
BACKGROUND
Chronic obstructive pulmonary disease (COPD) patients with blood eosinophil (EOS) count ≥ 2% benefit from exacerbation reductions with inhaled corticosteroids (ICSs). We conducted post hoc analyses to determine if EOS count ≥ 2% is a marker for greater responsiveness to the bronchodilators umeclidinium (UMEC; long-acting muscarinic antagonist), vilanterol (VI; long-acting β2-agonist) or UMEC/VI combination.


METHODS
Effects of once-daily UMEC/VI 62.5/25, UMEC 62.5 and VI 25 µg versus placebo on trough forced expiratory volume in one second (FEV1), Transition Dyspnoea Index (TDI), St George's Respiratory Questionnaire (SGRQ) scores and adverse event (AE) incidences in four completed, 6-month studies were assessed by EOS subgroup. Trough FEV1 was also evaluated by ICS use and EOS subgroup. Analyses were performed using a repeated measures model.


RESULTS
At baseline, 2437 of 4647 (52%) patients had EOS count ≥ 2%. Overall, ≈ 50% of patients used ICSs. At day 169, no notable variations were observed in trough FEV1 least squares mean differences between EOS subgroups versus placebo for UMEC/VI, UMEC and VI; results according to ICS use were similar. No differences were reported between EOS subgroups in TDI and SGRQ scores on day 168, or for incidences of AEs, serious AEs and AEs leading to withdrawal.


CONCLUSIONS
Response to UMEC/VI, UMEC and VI in terms of trough FEV1, dyspnoea and health-related quality of life was similar for COPD patients with baseline EOS counts ≥ 2 or <2%. EOS count did not appear to predict bronchodilator response in either ICS users or non-users.
Respiratory Franchise Medical, GSK, 5 Moore Drive, 5.3317, Research Triangle Park, NC, USA.
Ahmar
A
Iqbal
Respiratory Medical Franchise, GSK, Stockley Park West, 1-3 Ironbridge Road, Uxbridge, Middlesex, UB11 1BT, UK. neil.c.barnes@gsk.com.|The William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, London, UK. neil.c.barnes@gsk.com.
Neil C
NC
Barnes
Respiratory Medicines Development Centre, GSK, Stockley Park West, 1-3 Ironbridge Road, Uxbridge, Middlesex, UB11 1BT, UK.
Jean
J
Brooks
D058666:Adrenergic beta-2 Receptor Agonists / Q000008:administration & dosage / Q000627:therapeutic use; D000368:Aged; D001592:Benzyl Alcohols / Q000008:administration & dosage / Q000627:therapeutic use; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use*; D002722:Chlorobenzenes / Q000008:administration & dosage / Q000627:therapeutic use; D004311:Double-Blind Method; D004338:Drug Combinations; D004804:Eosinophils / Q000166:cytology* / Q000187:drug effects*; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D018727:Muscarinic Antagonists / Q000008:administration & dosage / Q000627:therapeutic use; D011237:Predictive Value of Tests; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood / Q000188:drug therapy*; D011788:Quality of Life; D011812:Quinuclidines / Q000008:administration & dosage / Q000627:therapeutic use; D016896:Treatment Outcome
D058666:Adrenergic beta-2 Receptor Agonists; D001592:Benzyl Alcohols; D001993:Bronchodilator Agents; D002722:Chlorobenzenes; D004338:Drug Combinations; C573971:GSK573719; D018727:Muscarinic Antagonists; D011812:Quinuclidines; C550468:vilanterol