An explorative, randomized, placebo-controlled, double-blind, parallel-group trial, to evaluate the pharmacodynamic effect of M0003 on reflux parameters in subjects with gastroesophageal reflux disease and with persistent symptoms despite taking a stable

This is an exploratory trial: 1. To measure the pharmacodynamic (PD) effect on parameters derived from 24-h pH/impedance (MII) monitoring, 2. To explore the effect on symptoms, 3. To evaluate the safety and tolerability of treatment with 0.5 mg M0003 (on top of PPI treatment), t.i.d. for 4 weeks, in subjects with GERD and with persistent symptoms despite taking a stable dose of proton pump inhibitors