Two once-daily long-acting muscarinic antagonists ( LAMAs ) are currently available for the treatment of chronic obstructive pulmonary disease ( COPD ), Tiotropium ( Spiriva ) and Glycopyrronium ( Seebri ).
Previous studies have compared Glycopyrronium with open-label Tiotropium. In the GLOW5 study, researchers have compared Glycopyrronium with blinded Tiotropium.
In this blinded, double-dummy, parallel group, 12-week study, patients with moderate-to-severe COPD were randomized 1:1 to Glycopyrronium 50 mcg once daily or Tiotropium 18 mcg once daily.
The primary objective was to demonstrate the non-inferiority of Glycopyrronium versus blinded Tiotropium with respect to trough forced expiratory volume in 1 second ( FEV1 ) following 12 weeks of treatment ( non-inferiority margin: -50 mL ).
Secondary objectives were to evaluate Glycopyrronium versus Tiotropium for other spirometric outcomes, breathlessness ( Transition Dyspnea Index; TDI ), health status ( St George's Respiratory Questionnaire; SGRQ ), daily rescue medication use, COPD exacerbations and COPD symptoms over 12 weeks of treatment.
A total of 657 patients was randomized ( Glycopyrronium: 327; Tiotropium: 330 ); 96% ( 630 patients ) completed the study.
Least squares mean trough FEV1 for both Glycopyrronium and Tiotropium was 1.405 L at Week 12, meeting the criterion for non-inferiority ( mean treatment difference: 0 mL ).
Glycopyrronium has demonstrated rapid bronchodilation following first dose on Day 1, with significantly higher FEV1 at all time points from 0-4 h post-dose versus Tiotropium ( all p less than 0.001 ).
FEV1 area under the curve from 0-4 h ( AUC0-4h ) post-dose with Glycopyrronium was significantly superior to Tiotropium on Day 1 ( p less than 0.001 ) and was comparable to Tiotropium at Week 12.
Glycopyrronium has demonstrated comparable improvements to Tiotropium in TDI focal score, SGRQ total score, rescue medication use and the rate of COPD exacerbations ( all p = not significant ).
Patients on Glycopyrronium also had a significantly lower total COPD symptom score versus patients on Tiotropium after 12 weeks ( p=0.035 ).
Adverse events were reported by a similar percentage of patients receiving Glycopyrronium ( 40.4% ) and Tiotropium ( 40.6% ).
In patients with moderate-to-severe COPD, 12-week blinded treatment with once-daily Glycopyrronium 50 mcg or Tiotropium 18 mcg, provided similar efficacy and safety, with Glycopyrronium having a faster onset of action on Day 1 versus Tiotropium. ( Xagena )
Chapman KR et al, BMC Pulm Med 2014;14:4. doi: 10.1186/1471-2466-14-4.