Serious asthma events with mometasone furoate plus formoterol compared with mometasone furoate.

Background: The safety of long-acting β-agonists added to inhaled corticosteroids for the treatment of persistent asthma has been controversial.

Objective: We sought to determine whether administering formoterol in combination with mometasone furoate increases the risk of serious asthma outcomes (SAOs) compared with mometasone furoate alone. This clinical trial is registered as NCT01471340.

Methods: We conducted a 26-week, randomized, double-blind trial in adolescent and adult patients (≥12 years) with persistent asthma in 35 countries with the primary objective of evaluating whether mometasone furoate-formoterol increases the risk of SAOs (adjudicated hospitalization, intubation, or death) compared with mometasone furoate alone. The key efficacy end point was asthma exacerbation (composite of hospitalization of ≥24 hours, emergency department visits of <24 hours requiring systemic corticosteroids, or use of systemic corticosteroids for ≥3 consecutive days).

Results: Among 11,729 patients (mometasone furoate-formoterol, n = 5,868; mometasone furoate, n = 5,861), a total of 81 SAOs, all asthma-related hospitalizations, were observed in 71 patients: 45 events from 39 patients receiving mometasone furoate-formoterol and 36 events from 32 patients receiving mometasone furoate. The hazard ratio for the first SAO in the mometasone furoate-formoterol versus mometasone furoate group was 1.22 (95% CI, 0.76-1.94; P = .411). Asthma exacerbation occurred in 1,487 patients: 708 receiving mometasone furoate-formoterol and 779 receiving mometasone furoate. The hazard ratio for the first asthma exacerbation in the mometasone furoate-formoterol versus mometasone furoate group was 0.89 (95% CI, 0.80-0.98; P = .021).

Conclusions: The addition of formoterol to mometasone furoate maintenance therapy did not increase the risk of serious asthma-related events and reduced the risk of asthma exacerbation.