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Phathom PHARMACEUTICALS TM Phathom Pharmaceuticals Announces Positive Topline Results from PHALCON - EE Pivotal Phase 3 Erosive Esophagitis Trial October 18 , 2021 • Vonoprazan met its primary non - inferiority endpoints in both healing and maintenance phases • Vonoprazan demonstrated superior healing rates in patients with moderate - to - severe disease at Week 2 versus lansoprazole ( PREVACIDⓇ ) , a proton pump inhibitor ( PPI ) • Vonoprazan demonstrated superior maintenance of healing in all patients and patients with moderate - to - severe disease versus lansoprazole at Week 24 • New Drug Application ( NDA ) submission planned for H1 2022 targeting the following indications : healing of all grades of erosive esophagitis ( EE ) and relief of heartburn , and maintenance of healing of all grades of EE and relief of heartburn • Phathom to host conference call today , October 18 , 2021 , at 8:30 am ET FLORHAM PARK , N.J. , Oct. 18 , 2021 ( GLOBE NEWSWIRE ) -- Phathom Pharmaceuticals , Inc. ( Nasdaq : PHAT ) , a late clinical - stage biopharmaceutical company focused on developing and commercializing novel treatments for gastrointestinal diseases , today announced that vonoprazan successfully met its primary endpoints and key secondary superiority endpoints in PHALCON - EE , a pivotal phase 3 trial evaluating vonoprazan versus lansoprazole for the treatment of erosive esophagitis . Based on the positive PHALCON - EE data , Phathom plans to submit an NDA to the U.S. Food and Drug Administration seeking the following indications : healing of all grades of EE and relief of heartburn , and maintenance of healing of all grades of EE and relief of heartburn . " The PHALCON - EE results are a major milestone for Phathom and for the 20 million Americans suffering from erosive esophagitis . The results further solidify vonoprazan's potential to be the first major innovation in the U.S. and European GERD market in more than 30 years , " said Terrie Curran , Phathom's President and Chief Executive Officer . " The results demonstrated that vonoprazan is superior to a standard of care PPI across a broad range of clinically relevant endpoints in the study , importantly including the maintenance of healing erosions at 24 weeks for all EE patients . We are excited about the potential for vonoprazan to satisfy the large unmet needs of so many patients and set a new treatment paradigm in EE . We thank the patients , physicians , and clinical sites who participated in the PHALCON - EE study during the height of the COVID - 19 pandemic , and we look forward to submitting an NDA and , if approved , making this treatment available for EE patients . " Study Design PHALCON - EE was a trial with two phases . In the first phase , vonoprazan 20 mg was compared to lansoprazole 30 mg in the healing of EE after up to 8 weeks of treatment ( Healing Phase ) . In the Healing Phase , patients were assessed via endoscopy to determine complete healing following 2 weeks of treatment and , if complete healing was not achieved , a second endoscopy occurred at 8 weeks of treatment . Patients who achieved complete healing were re - randomized into the second phase of the trial , where vonoprazan 10 mg and 20 mg were compared to lansoprazole 15 mg to assess maintenance of healing via endoscopy following 24 weeks of treatment ( Maintenance Phase ) . Heartburn symptom relief was assessed via secondary endpoints in both the Healing and Maintenance Phases of the study based on twice daily e - diary data collection . Study Results Healing Phase The primary endpoint of the Healing Phase was non - inferiority of vonoprazan 20 mg compared to lansoprazole 30 mg in the percentage of all patients who have complete healing of EE by Week 8. Vonoprazan met the Healing Phase primary endpoint with a healing rate of 93 % compared to 85 % for lansoprazole ( p < 0.0001 ) . In a preplanned exploratory superiority test , the difference between vonoprazan and lansoprazole was also significant ( p < 0.0001 ) .1 Vonoprazan met the secondary superiority endpoint of healing in patients with moderate - to - severe disease ² at Week 2 , demonstrating significantly faster healing than lansoprazole ( 70 % for vonoprazan 20 mg and 53 % for lansoprazole 30 mg ) ( p = 0.0004 ) . Vonoprazan 20 mg was also compared to lansoprazole 30 mg in a superiority test for onset of sustained resolution of heartburn by day 3 but did not achieve statistical significance ( p = 0.2196 ) . In additional secondary endpoint superiority comparisons , vonoprazan 20 mg healing rates were numerically greater than lansoprazole 30 mg in all patients at Week 2 ( p = 0.0174 ) ³ and in moderate - to - severe patients² by Week 8 ( p < 0.0001 ) ³ although deemed nominally significant due to the sequential testing method . Vonoprazan also met the secondary endpoint of showing non - inferiority to lansoprazole 30 mg in the mean percentage of 24 - hour heartburn free days over the healing period . Maintenance Phase Vonoprazan met the primary and all secondary endpoints in the Maintenance Phase . The primary endpoint of the Maintenance Phase was non - inferiority of vonoprazan 10 mg and 20 mg compared to lansoprazole 15 mg in the percentage of all patients who maintained healing of EE through Week 24 .