Abstract
Rationale: People with obesity often have severe, difficult-to-control asthma. There is a need to develop better treatments for this population. One potential treatment is roflumilast, a phosphodiesterase 4 inhibitor, as it is reported to have efficacy for the treatment of asthma and can promote weight loss. Objectives: To investigate the potential efficacy of roflumilast for the treatment of poorly controlled asthma in people with obesity. Methods: A randomized, double-masked, placebo-controlled trial of 24 weeks of roflumilast versus placebo for the treatment of poorly controlled asthma in people with obesity (body mass index of 30 kg/m(2) or higher). The primary outcome was a change in ACT (Asthma Control Test) score. Results: Twenty-two people were randomized to roflumilast and 16 to placebo. Roflumilast had no effect on change in the ACT (increased by 2.6 [interquartile range (IQR), 0.5-4.4] in those on roflumilast vs. 2.0 [IQR, 0.7-3.3] in those on placebo). Participants assigned to roflumilast had a 3.5-fold (relative risk [RR] 95% confidence interval [CI], 1.3-9.4) increased risk of an episode of poor asthma control and an 8.1-fold (RR 95% CI, 1.01-65.0) increased risk of an urgent care visit for asthma. Ten participants (56%) assigned to roflumilast required a course of oral corticosteroids for asthma exacerbations, and none in the placebo group. Participants losing 5% or more of their body weight experienced a clinically and statistically significant improvement in asthma control (ACT increased by 4.4 [IQR, 2.5-6.3] vs. 1.5 [IQR, 0.0-3.0] in those who lost less than 5%). Conclusions: Roflumilast had no effect on asthma control. Of concern, roflumilast was associated with an increased risk of exacerbation in obese individuals with poorly controlled asthma. These results highlight the importance of studying interventions in different subpopulations of people with asthma, particularly people with obesity and asthma who may respond differently to medications than lean people with asthma. Weight loss of at least 5% was associated with improved asthma control, indicating that interventions other than roflumilast promoting weight loss may have efficacy for the treatment of poorly controlled asthma in people with obesity. Clinical trial registered with www.clinicaltrials.gov (NCT03532490).