The objective of this study is to evaluate the safety and efficacy of IW-3718 administered to patients with GERD who continue to have persistent symptoms, such as heartburn and regurgitation, while receiving once-daily (QD), standard-dose proton pump inhibitors (PPIs).
Experimental: Three 500 mg study drug tablets administered twice daily (BID), immediately after the morning and evening meals.
Placebo Comparator: Three placebo tablets administered BID immediately after the morning and evening meals.