As per notification published on 29 September 2020, the clinical development study for IW-3718 (gastric-retentive investigational formulation of colesevelam) has been dropped since the early efficacy evaluation indicated the drug was not linked with substantial improvements in the severity of heartburn.

This phase III placebo-controlled clinical trial (IW-3718-302) was conducted to explore the IW-3718's efficacy and safety in GERD patients who had persistent symptoms despite their treatment with a standard dose of a proton pump inhibitor (n=550). This investigational bile acid sequestrant was intended to be maintained in the stomach for a prolonged period where it was anticipated to intercept bile before it reaches the esophagus.

Participants were randomly assigned to either three 500 mg IW-3718 tablets or three placebo tablets twice daily, following the morning and evening meals. The alteration in weekly heartburn severity score from baseline at week 8 was the primary study outcome.

An evaluation by the data monitoring committee verified that the trial did not fulfill the primary outcome parameter. The trial's outcomes were highly unsatisfactory, given the large unfulfilled requirement in patients having refractory GERD for a substitute to the standard management options. Thus, this trial was discontinued.