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Phathom PHARMACEUTICALS TM Phathom Pharmaceuticals Announces Positive Topline Results from Pivotal Phase 3 Trial of Vonoprazan in Helicobacter pylori ( H. pylori ) Infection ; Study Met All Primary and Secondary Endpoints April 29 , 2021 • Both vonoprazan - based treatment regimens demonstrated superior eradication rates vs. a standard of care proton pump inhibitor ( PPI ) -based triple therapy • New Drug Application ( NDA ) submissions targeted for Q4 2021 • Phathom to host conference call and live webcast today , April 29 , 2021 at 4:30 pm ET FLORHAM PARK , N.J. , April 29 , 2021 ( GLOBE NEWSWIRE ) -- Phathom Pharmaceuticals , Inc. ( Nasdaq : PHAT ) , a late clinical - stage biopharmaceutical company focused on developing and commercializing novel treatments for gastrointestinal diseases , announced today that in PHALCON - HP , its pivotal Phase 3 clinical trial for the eradication of H. pylori infection , both vonoprazan - based regimens successfully met their primary endpoints and met all secondary endpoints . The trial studied vonoprazan in combination with amoxicillin and clarithromycin ( " vonoprazan triple therapy " ) and vonoprazan in combination with amoxicillin ( " vonoprazan dual therapy " ) compared to lansoprazole in combination with amoxicillin and clarithromycin ( " lansoprazole triple therapy " ) . PHALCON - HP is the largest Phase 3 registration trial ever conducted in H. pylori infection , randomizing 992 patients with confirmed H. pylori infection . Phase 3 Topline Results Primary endpoint analysis The primary endpoints in the PHALCON - HP study were non - inferiority of the H. pylori eradication rate for each of vonoprazan triple and dual therapy compared to lansoprazole triple therapy . Based on U.S. Food and Drug Administration ( FDA ) feedback , the primary endpoint excluded patients with amoxicillin or clarithromycin resistant strains of H. pylori . Both vonoprazan - based regimens successfully met their primary endpoints . In the modified intent - to - treat ( mITT ) population , H. pylori eradication rates were 84.7 % with vonoprazan triple therapy and 78.5 % for vonoprazan dual therapy compared to 78.8 % with lansoprazole triple therapy ( p < 0.0001 and p = 0.0037 , respectively , for non - inferiority ) . Additional efficacy analyses were conducted using the pre - specified per protocol population , a subset of the mITT population comprised of patients who were protocol compliant as defined by FDA draft Guidance for Industry 1. In the per protocol population , H. pylori eradication rates were 90.4 % with vonoprazan triple therapy and 81.2 % with vonoprazan dual therapy compared to 82.1 % with lansoprazole triple therapy ( p < 0.0001 and p = 0.0077 , respectively , for non - inferiority ) . Secondary endpoint analysis Vonoprazan triple therapy and vonoprazan dual therapy also met all secondary endpoints , demonstrating superior eradication rates versus lansoprazole triple therapy in all patients and patients with clarithromycin resistant strains of H. pylori . Patients with clarithromycin resistant strains comprised 20.3 % of the PHALCON - HP study population . Vonoprazan triple therapy The H. pylori eradication rate of vonoprazan triple therapy was superior to that of lansoprazole triple therapy among all patients in both the mITT population ( 80.8 % vs. 68.5 % ; p = 0.0001 ) and the per protocol population ( 85.7 % vs. 70.0 % ; p < 0.0001 ) . The H. pylori eradication rate with vonoprazan triple therapy was superior to that of lansoprazole triple therapy in the subset of patients with H. pylori strains resistant to clarithromycin in both the mITT population ( 65.8 % vs. 31.9 % ; p < 0.0001 ) and the per protocol population ( 67.2 % vs. 29.0 % ; p < 0.0001 ) . Vonoprazan dual therapy The H. pylori eradication rate of vonoprazan dual therapy was superior to that of lansoprazole triple therapy among all patients in both the mITT population ( 77.2 % vs. 68.5 % ; p = 0.0063 ) and the per protocol population ( 81.1 % vs. 70.0 % ; p = 0.0013 ) . The H. pylori eradication rate of vonoprazan dual therapy was superior to that of lansoprazole triple therapy in the subset of patients with H. pylori strains resistant to clarithromycin in both the mITT population ( 69.6 % vs. 31.9 % ; p < 0.0001 ) and the per protocol population ( 79.5 % vs. 29.0 % ; p < 0.0001 ) . " Acid suppression is a key factor in addressing shortcomings associated with currently available H. pylori treatments , especially in light of increased resistance to antibiotics , including clarithromycin , " said Professor William D. Chey , M.D. , AGAF , FACG , FACP , Professor of Medicine and Director of the GI Physiology Laboratory at the University of Michigan . " I am very impressed with the results of PHALCON - HP which demonstrate that replacing a PPI with vonoprazan in H. pylori treatment regimens has the potential to meaningfully enhance eradication rates that have been declining over the last two decades . Further , the potential to limit the use of clarithromycin with a dual therapy regimen has the potential to transform clinical practice . "