A Randomized, Double-blind, Placebo-controlled,Trial of IW-3718 for 8 Weeks in Patient With Symptomatic GERD

This study is a multicenter, randomized, double-blind, placebo-controlled, parallel-group,
8-week study, consisting of 3 distinct periods: a screening period, pretreatment period, and
treatment period. The study will enroll patients who have GERD and continue to experience
GERD symptoms while receiving QD, standard-dose PPI therapy. Eligible patients will continue
to take their PPI and will be randomized to placebo or to one of three doses of study drug.

Inclusion Criteria:

- Patient is an ambulatory, community-dwelling male or nonpregnant female and is at
least 18 years old at the Screening Visit. Lactating females must agree not to
breastfeed.

- Patient has a diagnosis of GERD and reports experiencing GERD symptoms (heartburn or
regurgitation) on ≥ 4 days per week during the 8 weeks before the Screening Visit
while taking standard QD PPI therapy.

Exclusion Criteria:

- Patient may not meet any of the excluded conditions specified in the protocol

- Patient has any alarm symptoms including but not limited to GI bleeding, anemia,
vomiting, dysphagia, or unexpected weight loss any time during the Screening or
Pretreatment Periods

- Patient has a history of clinically significant hypersensitivity or allergies to any
of the excipients contained in the study medication (active or placebo).