Phathom Pharmaceuticals, Inc. announced that the U.S. Food and Drug Administration (FDA) has approved the Prior Approval Supplement (PAS) for the reformulation of vonoprazan tablets for both VOQUEZNA TRIPLE PAK (vonoprazan tablets, amoxicillin capsules, clarithromycin tablets) and VOQUEZNA DUAL PAK (vonoprazan tablets, amoxicillin capsules), for the treatment of Helicobacter pylori (H. pylori) infection in adults. VOQUEZNA treatment regimens contain antibiotics conveniently packaged with vonoprazan, a novel potassium-competitive acid blocker (PCAB) and the first innovative acid suppressant from a new drug class approved in the U.S. in over 30 years. These initial product approvals were based on safety and efficacy data from the Phase 3 PHALCON-HP trial, the largest U.S. registrational trial ever conducted in H. pylori, randomizing 1,046 patients.

In the modified intent-to-treat population, both VOQUEZNA treatment regimens demonstrated 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 VOQUEZNA TRIPLE PAK compared to 78.8% with lansoprazole triple therapy [95% CI: -0.8, 12.6] and 78.5% for VOQUEZNA DUAL PAK compared to 78.8% with lansoprazole triple therapy [95% CI: -7.4, 6.8]. VOQUEZNA TRIPLE PAK and DUAL PAK demonstrated superior eradication rates compared to PPI-based triple therapy (lansoprazole with amoxicillin and clarithromycin) among all patients, including in patients with clarithromycin resistant strains of H. pylori.1 The H. pylori eradication rate with VOQUEZNA TRIPLE PAK was 80.8% versus 68.5% with lansoprazole triple therapy in the overall study population [95% CI: 5.7, 18.8] and in patients who had a clarithromycin-resistant strain of H. pylori, 65.8% vs.

31.9%, respectively [95% CI: 17.7, 48.1].1H. pylori eradication rates for VOQUEZNA DUAL PAK were 77.2% versus 68.5% with lansoprazole triple therapy in the overall study population [95% CI: 1.9, 15.4] and in patients who had a clarithromycin-resistant strain of H. pylori, 69.6% vs. 31.9%, respectively [95% CI: 20.5, 52.6].

Adverse event (AE) rates for the vonoprazan-based regimens were comparable to lansoprazole triple therapy in the trial. The most common AEs (>2.0%) reported in the VOQUEZNA TRIPLE PAK, VOQUEZNA DUAL PAK, and lansoprazole triple therapy arms, respectively, were 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%). VOQUEZNA TRIPLE and DUAL PAKs are expected to be available in the U.S. in December 2023 and marketed exclusively by Phathom Pharmaceuticals, Inc. Phathom is planning for a combined U.S. commercial launch of VOQUEZNA TRIPLE PAK and VOQUEZNA DUAL PAK, together with vonoprazan for Erosive GERD, if approved.

Phathom plans to host an investor conference call in November 2023, following FDA action on the pending Erosive GERD New Drug Application, which has a PDUFA target action date of November 17, to discuss the Company?s U.S. commercial launch plans.