This is a randomized, double-blind, active comparator-controlled study with a parallel-group design including four arms with X842 and one arm with Lansoprazole.
Randomization to one of the treatments with X842 twice daily (BID) 25 mg, 50 mg, 75 mg, 100 mg, or Lansoprazole 30 mg once daily (QD) will be based on a 1:1:1:1:1 scheme.
The duration of each patient's participation in the study, including screening, blind treatment period, and open-label treatment period will be approximately 60 days. The patients will be randomized for 4 weeks of double-blind treatment and will be provided with investigational medicinal product for 35 days.
All patients will have an endoscopic evaluation after 4 weeks of treatment. Following the endoscopic evaluation, all patients will receive subsequent 4 weeks of open-label treatment with Lansoprazole. Repeated symptom evaluation to detect symptom patterns will be assessed during this period.
