ADX10059 as an add-on Therapy to Proton Pump Inhibitors (PPIs) in Patients With Gastroesophageal Reflux (GERD)

Inclusion Criteria: * diagnosis of typical GERD * partial responder to a stable standard clinical symptoms control dose of PPI therapy * body mass index ≤ 32 kg/m2 Exclusion Criteria: * exclusively atypical symptoms of GERD * symptoms that have been shown not to be associated with GERD * erosive oesophagitis * treated with a dose of PPI greater than the dose indicated for clinical symptom control of GERD * hiatus hernia \> 3 cm * current diagnosis of co-existing psychiatric disease * known clinical significant allergy or known hypersensitivity to drugs * is pregnant or breast-feeding * has received sodium valproate or topiramate within 30 days of Screening * has a history of a significant medical condition that may affect the safety of the patient or preclude adequate participation in the study