Efficacy and safety of AZD1981, a CRTH2 receptor antagonist, in patients with moderate to severe COPD

Objective: To evaluate the efficacy and tolerability of the selective CRTh2 (DP2) receptor antagonist AZD1981 compared with placebo in patients with moderate to severe COPD.

Methods: In this multicentre, randomised, double-blind, parallel-group, phase IIa study (ClinicalTrials.gov identifier: NCT00690482) patients with moderate to severe COPD received either AZD1981 1000 mg twice daily or matching placebo for 4 weeks. Inhaled terbutaline was used as-needed as reliever medication throughout. The co-primary endpoints were change from baseline to end of treatment in pre-bronchodilator forced expiratory volume in 1 s [FEV1] and the Clinical COPD Questionnaire (CCQ). Additional endpoints included other lung function measures, 6-min walk test (6-MWT), COPD symptom score, reliever medication use and tolerability.

Results: 118 patients were randomised to treatment (AZD1981 n = 61; placebo n = 57); 83% of patients were male and the mean age was 63 years (range 43-83). There were no significant differences in the mean difference in change from baseline to end of treatment between AZD1981 and placebo for the co-primary endpoints of pre-bronchodilator FEV1 (AZD1981-placebo: -0.015, 95% CI: -0.10 to 0.070; p = 0.72) and CCQ total score (difference: 0.042, 95% CI: -0.21 to 0.30; p = 0.75). Similarly, no differences were observed between treatments for the other outcomes of lung function, COPD symptom score, 6-MWT, BODE index, and use of reliever medication. AZD1981 was well tolerated.

Conclusion: There was no beneficial clinical effect of AZD1981, at a dose of 1000 mg twice daily for 4 weeks, in patients with moderate to severe COPD. AZD1981 was well tolerated and no safety concerns were identified.