For the past decade, clinicians have largely followed a set of similar algorithms for chronic obstructive pulmonary disease (COPD) therapy, initiating treatment with an inhaled longacting antimuscarinic (LAMA) and adding combination therapy with a longacting β agonist (LABA) plus an inhaled corticosteroid when symptom or exacerbation control is inadequate. This algorithm is also in accordance with the Global initiative for chronic Obstructive Lung Disease (GOLD) 2007 consensus statement.1 However, the GOLD 2013 consensus statement challenges clinicians to rethink this routine.2 A wide range of treatment options are proposed including LAMA/LABA dual therapy, which is recommended as a treatment alternative for group B (high symptoms/low risk), C (low symptoms/high risk), and D (high symptom/high risk) patients. However, few data have been available to support the efficacy of this combination therapy over single agent bronchodilator therapy. Good data already exist for the efficacy of LAMA monotherapy for symptom control and exacerbation reduction3 as well as for the efficacy of LABA monotherapy for symptom control,4 but scarce data have been available for whether dual agent therapy has additional benefit in terms of either symptom control or exacerbation reduction.
In The Lancet Respiratory Medicine, Jadwiga Wedzicha and colleagues5 present data from the SPARK study, a randomised, three-group, double-blind study in COPD comparing once-daily indacaterol plus glycopyrronium combination therapy (QVA149) versus glycopyrronium alone versus open-label tiotropium. The primary endpoint examined was superiority of QVA149 versus glycopyrronium in reducing the frequency of moderate to severe COPD exacerbations, with the comparison of QVA149 versus tiotropium as a major secondary endpoint. Inclusion criteria were post-bronchodilator forced expiratory volume in 1 s (FEV1) less than 50% and at least one exacerbation in the previous 12 months. This study showed a 12% reduction in the rate of moderate to severe exacerbations for QVA149 compared with glycopyrronium (rate ratio [RR] 0·88, 95% CI 0·77—0·99, p=0·038). The 10% reduction in moderate to severe exacerbations for QVA149 compared with tiotropium was not significant (RR 0·90, 95% CI 0·79—1·02, p=0·096). QVA149 also resulted in significantly higher trough FEV1 as compared to glycopyrronium (differences 70—80 mL, p<0·0001) and tiotropium (differences 60—80 mL, p<0·0001) and resulted in 8—9 unit improvements in St George’s Respiratory Questionnaire score (SGRQ) total score as opposed to 6 units with glycopyrronium and 5—6 units with tiotropium, both significant differences.
The real question is how these data should influence prescribing practices for COPD. These data support better lung function improvement, better symptom control, and greater exacerbation reduction with LAMA/LABA therapy as opposed to LAMA therapy alone in patients with severe to very severe disease. In reality, such patients are likely to be on some form of therapy before they progress to this level of disease severity. Hence for the patient already on LAMA therapy, the addition of a LABA, particularly if exacerbation reduction is a goal, as a next step in therapy is supported by these data.
These data must be interpreted in light of the fact that about 75% of patients were on concomitant inhaled corticosteroids, which has several implications. First, the magnitude of exacerbation reduction seen was 12%, which is arguably clinically significant but might have been attenuated owing to concomitant inhaled corticosteroid use. These results mirror the magnitude of reduction seen with tiotropium in the UPLIFT study,3 in which concomitant inhaled corticosteroid plus LABA therapy was allowed. Second, the high rates of concomitant inhaled corticosteroid use also mean that these data perhaps provide less support for the GOLD recommendation of LABA/LAMA as dual therapy for either groups C or D and perhaps provide greater support for triple therapy (addition of LABA to LAMA plus inhaled corticosteroids) for C and D patients.
In further thinking about how these data inform prescribing practices, one should also note that 22% of patients studied had two or more moderate or severe exacerbations in the previous year. Previous data suggest that group D patients who are judged to be at high risk by both FEV1 and exacerbation criteria are at even greater risk of moderate and severe exacerbations than are those meeting a single criterion, suggesting good efficacy in a relatively high risk population.6 On the other hand, another interesting finding of the study was that the greatest reduction was seen in mild exacerbations—15% with QVA149 compared with glycopyrronium and 16% compared with tiotropium—with mild exacerbations defined as an event with increase in symptoms but self-managed by the patient. Although exacerbation events requiring therapy are more frequently studied, the importance of untreated events should not be underestimated. Even events unreported to a health-care provider have been shown to be associated with significantly worse health status,7 which might explain the improvements in SGRQ score seen with QVA149 therapy.
Overall, these data support greater efficacy for dual bronchodilator therapy with QVA149 as compared with LAMA monotherapy. In view of the lack of data in the past, the use of combination LABA/LAMA therapy has not been embraced by medical practitioners for use in COPD, but these new data suggest dual therapy is an important therapeutic option when trying to maximise symptom improvement and exacerbation reduction.