Objective To evaluate the efficacy and tolerability of add-on treatment with lesogaberan (AZD3355), a novel reflux inhibitor, in patients with persistent gastro-oesophageal reflux disease (GORD) symptoms despite proton pump inhibitor (PPI) therapy.

Methods A double-blind, placebo-controlled, randomised, parallel-group, multicentre phase IIA study was carried out in outpatient clinics. The study group comprised 244 adult patients with persistent GORD symptoms (heartburn and/or regurgitation) of at least mild intensity and for 3 days of 7 days before enrolment, despite ≥6 weeks of continuous PPI therapy. Patients received either lesogaberan (65 mg twice daily) or placebo in addition to PPI therapy for a period of 4 weeks. Symptom intensity, based on the Reflux Disease Questionnaire, was recorded twice daily. Treatment response (defined as at most one 24 h period with heartburn or regurgitation of not more than mild intensity during the last 7 days of treatment). Time to response, proportion of symptom-free days and measures of tolerability were also analysed.

Results A total of 232 (114 lesogaberan- and 118 placebo-treated patients) of the 244 randomised patients were analysed for efficacy. Treatment with lesogaberan, compared with placebo, resulted in a significantly larger proportion of responders to treatment (16% vs 8% of patients; p=0.026) and cumulative proportion of responders over time (log-rank p=0.0195). Lesogaberan was well tolerated: adverse events of mostly mild to moderate intensity were reported in 45% of patients on lesogaberan and in 37% on placebo.

Conclusions Lesogaberan add-on therapy to PPIs significantly improved heartburn and regurgitation symptoms; however, the proportion of responders was small.

Clinical trial number NCT00394472.