There have been multiple studies of the combination in more than 17 000 patients. These have established the usual dose of fluticasone furoate/vilanterol to be 100/25 microgram once daily. Some patients with asthma will need 200/25 microgram, but this dose is not indicated in patients with COPD.
Asthma
The efficacy of the combination was compared with fluticasone products in patients with persistent asthma. These patients were at least 12 years old and had a forced expiratory volume in one second (FEV1) that was 40–90% of the predicted value. Following a run-in period, 197 patients were randomised to use the combination (200/25 microgram daily), 194 inhaled fluticasone furoate (200 microgram daily) and 195 inhaled fluticasone propionate (500 microgram twice daily). The mean pre-dose (trough) FEV1 at baseline was 2.153 L. After 24 weeks this had improved by 394 mL with the combination, by 201 mL with fluticasone furoate and by 183 mL with fluticasone propionate. The combination of fluticasone furoate and vilanterol therefore had a significantly greater effect on lung function than fluticasone alone.1
Another trial studied the effect of the combination on exacerbations of asthma. The 2020 adolescents and adults in the study had FEV1 values that were 50–90% of their predicted value, and a history of at least one exacerbation in the previous year. They were randomised to receive fluticasone furoate/vilanterol 100/25 microgram or fluticasone furoate 100 microgram daily. At least one severe exacerbation occurred in 340 patients. At one year, the risk of having an exacerbation was reduced by 20% in the patients inhaling the combination.2
The combination of fluticasone furoate and vilanterol (100/25 microgram) has been compared with the combination of fluticasone propionate and salmeterol (250/50 microgram). After a run-in period, 806 patients, with FEV1 40–85% of the predicted value, were randomised to inhale the drugs for 24 weeks. The mean FEV1 increased by 341 mL with the vilanterol combination and by 377 mL with the salmeterol combination. This difference is not statistically significant and there was also no difference in asthma control or exacerbations.3
Chronic obstructive pulmonary disease
Two placebo-controlled, parallel group trials studied different doses of fluticasone furoate and vilanterol in patients with COPD. These patients were at least 40 years old, had a smoking history of at least 10 pack-years and an FEV1 that was 70% or less than the predicted value after using a bronchodilator. In addition to the different doses of the combination, both trials had arms which included fluticasone furoate alone and vilanterol alone.4,5
The first trial randomised 1030 patients. After 24 weeks the mean trough FEV1 had increased by 33 mL with fluticasone furoate and by 67 mL with vilanterol, compared to placebo. The 100/25 microgram combination increased trough FEV1 by 115 mL more than placebo. This combination also significantly increased the mean FEV1 in the four hours following the inhalation (see Table).4
The second trial randomised 1224 patients. Compared to placebo, the trough FEV1 increased by 44 mL with fluticasone furoate, 100 mL with vilanterol and by 144 mL with the 100/25 microgram combination. After 24 weeks this combination had also increased the mean FEV1 in the four hours following the inhalation (see Table).5
Another two trials in similar groups of patients assessed the effect of vilanterol 25 microgram and different doses of the combination on exacerbations. These patients had a history of at least one exacerbation in the previous year. The first study randomised 1622 patients and the second study randomised 1633. A pooled analysis after one year showed that 48.9% of the patients taking vilanterol and 41.9% of those taking the 100/25 microgram combination had an exacerbation. This combination also significantly reduced the rate of moderate and severe exacerbations.6