Phathom Pharma's Vonoprazan Inhibits Gastric Acid In Healthy Volunteers

Phathom Pharmaceuticals Inc PHAT has reported results from the VONO-103 Phase 1 trial of vonoprazan in healthy subjects.
The trial evaluated the effects of vonoprazan 20 mg once daily and lansoprazole 30 mg.
In the study, vonoprazan demonstrated significantly greater acid inhibition as compared to lansoprazole.
The study treatments were generally well-tolerated, with no serious adverse events reported.
The primary pharmacodynamic endpoints of VONO-103 were mean gastric pH over twenty-four hours and the percentage of time with gastric pH above 4 on Days 1 and 7.
Following the first dose, the mean 24-hour gastric pH value on Day 1 for vonoprazan was 4.6 compared to 2.8 for lansoprazole.
The least-squares mean pH>4 HTR on Day 1 for vonoprazan was 62.2% compared to 23.2% for lansoprazole.
The greater gastric acid inhibition was maintained after seven days of once-daily dosing.
The mean 24-hour pH value on Day 7 for vonoprazan was 5.9 compared to 3.8 for lansoprazole.
The least-squares mean pH>4 HTR on Day 7 was 86.8% for vonoprazan compared to 42.1% for lansoprazole.
Phathom is also conducting PHALCON-EE, a Phase 3 study in patients with erosive esophagitis, comparing vonoprazan and lansoprazole.
Topline results of PHALCON-EE are expected in October 2021.
Price Action: PHAT stock is up 3.84% at $33.01 during the market session on the last check Monday.