FDA Accepts Review of NDA for Vonoprazan From Phathom Pharmaceuticals

The FDA accepted to review a new drug application (NDA) for vonoprazan (Phathom Pharmaceuticals) as a treatment for individuals who are healing all grade of erosive esophagitis (EE), as a relief of heartburn, and as maintenance of healing all grades of EE and relief of heartburn.¹

The FDA has assigned the application review and a Prescription Drug User Fee Act target action date of January 11, 2023.¹

“The FDA’s commencement of a substantive review of our NDA for vonoprazan in EE is an important milestone for Phathom and the patients we seek to serve, bringing us another step closer toward the approval of a new class of treatment and the first major innovation to the US GERD market in over 30 years,” Azmi Nabulsi, MD, chief operating officer at Phathom, said in a statement. “With this NDA filing, we are excited about our potential to offer a treatment option to address the significant unmet needs that exist for the millions of patients suffering from painful erosions caused by all grades of EE.”¹

The NDA is supported by positive data from the phase 3 PHALCON-EE trial, a double-blind, multicenter, randomized trial. Investigators enrolled 1027 individuals with EE in Europe and the United States and compared vonoprazan to lansoprazole, a proton pump inhibitor, in the healing and maintenance of EE and heartburn symptom relief.¹

The study met both its primary and key secondary endpoints.1 Vonoprazan met the healing phase primary endpoint, with a healing rate of 93% compared with 85% for lansoprazole, and both doses met the maintenance phase primary endpoint of non-inferiority.²

Additionally, vonoprazan met the secondary endpoint of healing in individuals with moderate-to-severe EE at week 2 by demonstrating significantly faster healing than lansoprazole at 70% and 53%, respectively.²

Furthermore, both doses met the secondary endpoint in the maintenance phase, demonstrating superiority of maintenance of healing compared with lansoprazole, at 79% for vonoprazan 10 mg, 81% for 20 mg, and at 72% for lansoprazole 15 mg.²

In the first phase of the trial, investigators evaluated the efficacy and safety of vonoprazan 20 mg administered once daily compared with lansoprazole 30 mg once daily for the healing of EE for up to 8 weeks.¹

In the second phase of the trial, investigators evaluated the efficacy and safety of vonoprazan 10 mg once daily and vonoprazan 20 mg once daily compared with lansoprazole 15 mg once daily for the maintenance of healing of EE for 24 weeks.¹

They also evaluated heartburn symptoms in both phases.¹

The most common adverse events were abdominal pain, diarrhea, dysgeusia, headaches, hypertension, nasopharyngitis, and vulvovaginal candidiasis.¹

Vonoprazan is a novel, orally administered investigational potassium-competitive acid blocker from a class of acid suppressant agents and under development for the treatment of EE and non-erosive gastroesophageal reflux disease, according to a statement from the company.¹

Reference

1. Phathom Pharmaceuticals announces FDA acceptance for filing of vonoprazan NDA for the treatment of erosive esophagitis. Phathom Pharmaceuticals. News release. May 25, 2022. Accessed May 26, 2022. Email.

2. Phathom Pharmaceuticals announces positive topline results from PHALCON-EE pivotal phase 3 erosive esophagitis trial. Phathom Pharmaceuticals. News release. October 18, 2021. Accessed May 26, 2022. https://investors.phathompharma.com/news-releases/news-release-details/phathom-pharmaceuticals-announces-positive-topline-results-0