Treatment with glycopyrrolate inhalation powder (GLY) resulted in significant lung function improvements regardless of whether or not patients with chronic obstructive pulmonary disease (COPD) were current smokers, according to a recent post-hoc analysis of the GEM1 and GEM2 studies published in Respiratory Research.

“These data support the use of GLY 15.6 μg [twice daily] in patients with moderate-to-severe COPD regardless of their baseline smoking status, although the magnitude of benefit may differ between current and ex-smokers,” Donald P. Tashkin, MD, from the David Geffen School of Medicine at the University of California at Los Angeles, and colleagues wrote in their study.

Pill Lung. Source: Getty Images

In the GEM1 and GEM2 studies, patients with moderate-to-severe COPD received GLY at a dose of 15.6 μg twice daily or placebo for 12 weeks, analyzing factors such as forced expiratory volume in 1 second (FEV1), area under the curve from 0 to 12 h, trough FEV1, forced vital capacity (FVC), COPD assessment test (CAT), St George’s Respiratory Questionnaire (SGRQ) total score, transition dyspnea index, use of rescue medication, and daily symptom scores. The researchers used 867 patients from both studies in a post-hoc analysis, where 57% of patients were current smokers and 43% of patients were ex-smokers.

Regardless of whether patients were current or ex-smokers, the glycopyrrolate group showed lung function improvement, and those who received inhaled corticosteroids (ICS) in addition to glycopyrrolate treatment had less improvement in trough FEV1 from baseline than patients who did not take ICS. Smoking status also did not impact SGRQ score and use of rescue medication from baseline measurements, and patients who received glycopyrrolate showed significantly greater improvement in those areas compared with patients in the placebo group. The safety profile for glycopyrrolate was also not impacted by whether a patient was a current or ex-smoker. 

However, CAT score, TDI focal score, and daily symptom scores significantly improved from baseline in the glycopyrrolate current smokers group, but not in the glycopyrrolate ex-smokers group.

“There was a significant difference between smokers and ex-smokers in the change from baseline in CAT score with placebo; this may have contributed to the treatment difference being smaller in ex-smokers than current smokers,” Tashkin and colleagues noted.

Patient-reported outcomes (PROs) of all symptoms were also greater for current smokers than in ex-smokers. “The differences observed in PROs between current and ex-smokers in this analysis may have been influenced by disease severity at baseline, with patients with more severe disease having possibly ceased smoking due to worse baseline lung function,” they said.