Efficacy and safety of antagonists for chemoattractant receptor-homologous molecule expressed on Th2 cells in adult patients with asthma: a meta-analysis and systematic review

Chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2) antagonists are novel agents for asthma but with controversial efficacies in clinical trials. Therefore, we conducted a meta-analysis to determine the roles of CRTH2 antagonists in asthma. We searched in major databases for RCTs comparing CRTH2 antagonists with placebo in asthma. Fixed- or random-effects model was performed to calculate mean differences (MD), risk ratio (RR) or risk difference (RD) and 95% confidence interval (CI). A total of 14 trails with 4671 participants were included in our final analysis. Instead of add-on treatment of CRTH2 antagonists to corticosteroids, CRTH2 antagonist monotherapy significantly improved pre-bronchodilator FEV1 (MD = 0.09, 95% CI 0.04 to 0.15, P = 0.0005), FEV1% predicted (MD = 3.65, 95% CI 1.15 to 6.14, P = 0.004), and AQLQ (MD = 0.25, 95% CI 0.09 to 0.41, P = 0.002), and reduced asthma exacerbations (RR = 0.45, 95% CI 0.23 to 0.85, P = 0.01). Rescue use of SABA was significantly decreased in both CRTH2 antagonist monotherapy (MD = − 0.04, 95% CI -0.05 to − 0.03, P < 0.00001) and as add-on to corticosteroids (MD = − 0.78, 95% CI -1.47 to − 0.09, P = 0.03). Adverse events were similar between the intervention and placebo groups. CRTH2 antagonist monotherapy can safely improve lung function and quality of life, and reduce asthma exacerbations and SABA use in asthmatics.