In a clinical trial, 2 vonoprazan-based regimens demonstrated higher rates of eradication as well as low rates of adverse effects compared to lansoprazole triple therapy.
The FDA has approved the prior approval supplement (PAS) for the reformulation of vonoprazan tablets for both vonoprazan tablets, amoxicillin capsules, and clarithromycin tablets (Voquenza Triple Pak; Phathom Pharmaceuticals) as well as vonoprazan tablets and amoxicillin capsules (Voquenza Dual Pak; Phathom Pharmaceuticals) for the treatment of Helicobacter pylori (H. pylori) infection in adult patients. The treatment regimens contain antibiotics packaged with vonoprazan, a novel potassium-competitive acid blocker and the first acid suppressant from a new drug class approved in the United States in over 30 years.
The approvals were based on safety and efficacy data from the phase 3 trial PHALCON-HP (NCT04167670). A total of 1046 enrolled patients with H. pylori were involved in the trial, with both treatment regimens in the intent-to-treat group demonstrating non-inferiority to lansoprazole triple therapy in patients without a clarithromycin or amoxicillin resistant strain of H. pylori at baseline. The H. pylori eradication rate was 84.7% with vonoprazan tablets, amoxicillin capsules, and clarithromycin tablets compared to 78.8% with lansoprazole triple therapy, and 78.5% for vonoprazan tablets and amoxicillin capsules compared with lansoprazole triple therapy.
Further, the treatment regimens demonstrated better eradication rates compared to proton pump inhibitor-based triple therapy (lansoprazole with amoxicillin and clarithromycin) among all patients, including patients with clarithromycin-resistant strains of H. pylori. The H. pylori eradication rate with vonoprazan tablets, amoxicillin capsules, and clarithromycin tablets was 80.8% compared to lansoprazole triple therapy (68.5%) in the overall study population, and 65.8% and 31.9%, respectively, in patients with a clarithromycin-resistant strain. In addition, the eradication rates for vonoprazan tablet and amoxicillin capsule treatment were higher than lansoprazole triple therapy (77.2% vs 68.5%, respectively), and patients with a clarithromycin-resistant strain showed eradication rates of 69.6% and 31.9%, respectively.
“We are very pleased with the FDA approval of our reformulated vonoprazan tablets for both [vonoprazan-based treatment regimens], 2 new first-line treatment options that offer strong H. pylori eradication rates,” said Terrie Curran, president and chief executive officer at Phathom, in a press release. “H. pylori eradication failures are due to rising antibiotic resistance, inadequate acid suppression, and complex treatment regimens. We are excited about [the vonoprazan-based treatment regimens], a new class of acid suppression therapy, that has the potential to address these issues and enhance H. pylori eradication.”
Adverse event (AE) rates for the vonoprazan-based regimens were comparable to lansoprazole triple therapy in the trial. The most common AEs reported across the vonoprazan tablet, amoxicillin capsule, and clarithromycin tablet, vonoprazan tablet and amoxicillin capsule, and lansoprazole triple therapy arms being diarrhea (4.0%, 5.2%, 9.6%), dysgeusia (4.6%, 0.6%, 6.1%), vulvovaginal candidiasis (3.2%, 2.0%, 1.4%), abdominal pain (2.3%, 2.6%, 2.9%), headache (2.6%, 1.4%, 1.4%), hypertension (2.0%, 1.1%, 0.9%), and nasopharyngitis (0.3%, 2.0%, 0.9%).
“Our teams are making the final preparations for a combined December 2023 [US] commercial launch for H. pylori along with the anticipated launch of vonoprazan for erosive [gastroesophageal reflux disease], if approved,” said Curran in the press release.
Biosoace. Phathom Pharmaceuticals Announces FDA Approval of Reformulated Vonoprazan Tablets for VOQUEZNA® TRIPLE PAK® (vonoprazan, amoxicillin, clarithromycin) and VOQUEZNA® DUAL PAK® (vonoprazan, amoxicillin) for the Treatment of H. pylori Infection in Adults. News release. October 30, 2023. Accessed October 30, 2023. https://www.biospace.com/article/releases/phathom-pharmaceuticals-announces-fda-approval-of-reformulated-vonoprazan-tablets-for-voquezna-triple-pak-vonoprazan-amoxicillin-clarithromycin-and-voquezna-dual-pak-vonoprazan-amoxicillin-for-the-treatment-of-h-pylori-infection-in-adults/