Vonoprazan was associated with a significantly greater percentage of 24-hour heartburn free days in patients with symptomatic nonerosive gastroesophageal reflux disease (NERD) compared with placebo, according to topline results from a phase 3 study.

Vonoprazan is an oral small molecule potassium-competitive acid blocker. The randomized, double-blind, multicenter PHALCON-NERD-301 study (ClinicalTrials.gov Identifier: NCT05195528) included 776 adults with symptomatic NERD. Patients were randomly assigned to receive either vonoprazan 10mg, 20mg or placebo once daily. The primary endpoint was the percentage of days without daytime or nighttime heartburn at week 4.

Findings showed a significantly greater percentage of 24-hour heartburn-free days with both doses of vonoprazan compared with placebo (mean 46.4% for 10mg, 46% for 20mg vs 27.5% for placebo; P <.0001). The median percentage of 24-hour heartburn-free days was 48.3% for vonoprazan 10mg, 46.7% for vonoprazan 20mg and 17% for placebo.

Vonoprazan was generally well tolerated with a safety profile consistent with that observed in previous studies. The most commonly reported adverse event was nausea.

“The topline data are expected to form the basis of our FDA submission seeking approval of vonoprazan as a daily treatment for patients with NERD, following completion of the long-term extension portion of the trial,” said Terrie Curran, Phathom’s President and Chief Executive Officer. “These data are very encouraging for the treatment of NERD, a highly prevalent category of gastroesophageal reflux disease that causes disruptive day and nighttime symptoms for over 45 million patients in the US.”


Phathom Pharmaceuticals announces positive topline results from phase 3 PHALCON-NERD-301 trial evaluating daily dosing of vonoprazan for symptomatic non-erosive gastroesophageal reflux disease (NERD). News release. Phathom Pharmaceuticals. Accessed January 9, 2023. https://www.globenewswire.com/news-release/2023/01/08/2584752/0/en/Phathom-Pharmaceuticals-Announces-Positive-Topline-Results-from-Phase-3-PHALCON-NERD-301-Trial-Evaluating-Daily-Dosing-of-Vonoprazan-for-Symptomatic-Non-Erosive-Gastroesophageal-Re.html.