Phathom Pharmaceuticals Highlights Breadth of Independent Vonoprazan Research at Digestive Disease Week 2026 Annual Meeting

• 31 vonoprazan-related clinical abstracts presented at Digestive Disease Week (DDW) 2026, including 28 independent analyses across GI conditions and three Phathom-sponsored clinical research abstracts
  
  
  
  
• Independent investigator-initiated studies reported findings on treatment of GERD, H. pylori eradication, long-term safety, and vonoprazan use post endoscopic submucosal dissection (ESD)
  
  
  
  
• Phathom-sponsored analysis of heartburn and regurgitation in patients on vonoprazan from the Phase 3 pHalcon-NERD-301 trial recognized by DDW as a Poster of Distinction
  
  
  
  

FLORHAM PARK, N.J., May 20, 2026 (GLOBE NEWSWIRE) -- Phathom Pharmaceuticals, Inc. (NASDAQ:PHAT), a biopharmaceutical company focused on commercializing and developing novel treatments for gastrointestinal (GI) diseases, today highlighted the growing body of clinical and scientific research on vonoprazan, the active ingredient in VOQUEZNA^® (vonoprazan), at Digestive Disease Week (DDW) 2026, held May 2–5, 2026 in Chicago, Illinois. Phathom presented three posters at the meeting, including a Phathom-sponsored analysis from the Phase 3 pHalcon-NERD-301 study that was recognized by DDW as a Poster of Distinction, a designation reserved for abstracts of notable scientific merit. Vonoprazan was also the subject of 28 additional independent, investigator-initiated abstracts across gastroesophageal reflux disease (GERD), Helicobacter pylori (H. pylori) eradication, long-term safety, and post endoscopic procedural care, reflecting the growing scientific interest in vonoprazan and the potassium-competitive acid blocker (PCAB) class in GI medicine.

"The breadth of data presented at DDW 2026 reflects the significant scientific interest in vonoprazan across multiple acid-related conditions," said Steve Basta, President and Chief Executive Officer of Phathom. "We are encouraged by the level of independent scientific engagement and the broad interest among researchers to evaluate vonoprazan in a range of conditions. The research highlighted at this year's meeting adds to the growing scientific understanding of vonoprazan across multiple areas of GI medicine."

Key data presented at DDW 2026 include:

• Meta-analysis of data from randomized controlled trials evaluating healing outcomes in patients with severe (LA Grade C and D) erosive esophagitis (Erosive GERD) treated with vonoprazan compared to the proton pump inhibitor (PPI) lansoprazole
• Analyses from the Phase 3 pHalcon-NERD-301 study evaluating both heartburn and regurgitation symptoms in patients with Non-Erosive GERD (NERD) treated with vonoprazan versus placebo, as measured by the validated PAGI-SYM patient-reported outcome instrument
• Real-world data evaluating vonoprazan in patients with PPI-refractory GERD following laparoscopic sleeve gastrectomy
• Multiple independent meta-analyses evaluating H. pylori eradication rates with vonoprazan-based regimens, including a network meta-analysis of 77 randomized controlled trials comparing treatment strategies
• Real-world propensity-matched cohort analyses evaluating safety outcomes associated with vonoprazan and traditional PPIs, including rates of vitamin B12 deficiency, hypomagnesemia, and Clostridioides difficile (C. diff) infection
• Two independent systematic reviews and meta-analyses evaluating delayed post-procedural bleeding following endoscopic submucosal dissection (ESD) in patients treated with vonoprazan compared to PPIs
• Post hoc analyses from the multicenter, prospective, real-world observational study evaluating vonoprazan in Chinese patients with reflux esophagitis across patient subpopulations including elderly patients and those with comorbid anxiety or depression
  
  
  
  

Vonoprazan Abstracts Presented at DDW 2026:

28 independent abstracts reflect investigator-initiated research conducted by academic and clinical scientists across the United States, Europe, Asia, and South America:

Independent Research on Vonoprazan:

GERD

• Potassium-Competitive Acid Blockers Versus Proton Pump Inhibitors in Patients with Grade C and D Erosive Esophagitis: A Meta-Analysis (He E et al.; Tu1173)
• Use Morning or/and Evening Dosing of Vonoprazan for Gastroesophageal Reflux Disease: An Interim Analysis for a Randomized Crossover Trial (Wang D et al.; Tu1163)
• Real-World Prescription Patterns of Potassium-Competitive Acid Blockers (PCABs) in Erosive Esophagitis: A New Era in Acid Suppression (Chalhoub M et al.; Tu1167)
• Effectiveness and Safety of Vonoprazan in Elderly Chinese Patients with Gastroesophageal Reflux Disease: A Post Hoc Analysis of the VIEW Study (Liang K et al.; Tu1165)
• Effectiveness of Vonoprazan on Symptom Relief in Gastroesophageal Reflux Disease Patients with Anxiety or Depression: A Post Hoc Analysis of the VIEW Study (Liang K et al.; Tu1168)
• Vonoprazan Improves GERD Symptoms and Heals Erosive Esophagitis in Patients with Gastric Sleeve Refractory to High Dose PPI (Cricco-Lizza E et al.; Presentation 972)
  
  
  
  

Safety

• Real World Evaluation of Adverse Events Associated with Vonoprazan Compared with Traditional Proton Pump Inhibitors (Al Momani Z et al.; Su1277)
• Long Term Safety of Vonoprazan Compared with Proton Pump Inhibitors: A Large Multi-Center Real World Propensity Matched Cohort (Alsafi W et al.; Tu1221)
• The Risk of Clostridioides Difficile Infection with Vonoprazan Compared to Proton Pump Inhibitors: A Large Multi-Center Cohort Study (Cohen E et al.; Sa1333)
• Potassium-Competitive Acid Blockers and Risk of Small Intestinal Bacterial Overgrowth and Nutrient Deficiencies: A Global Real-World Study (Luo A et al.; Su1273)
• Vonoprazan Does Not Increase the Incidence of Benign Gastric Polyps Compared with Proton Pump Inhibitors (Simadibrata D et al.; 1123)
• PCABs Are Associated with Low Rates of Short-Term Adverse Events: A Global Cohort Study Comparing PCABs Versus PPIs (Lee ME et al.; Poster 963)
  
  
  
  

H. pylori Eradication

• First-Line Empirical Eradication Therapy for H. pylori Infection: Experience from 1,500 Cases of the Brazilian H. pylori Registry (Friche Passos M et al.; Tu1224)
• Efficacy of Potassium-Competitive Acid Blocker (PCAB)-Based Therapies for H. pylori Infection: A Network Meta-Analysis of 77 Randomized Controlled Trials (Song Z et al.; Tu1223)
• Comparative Efficacy and Safety of Vonoprazan-Based Dual Therapy Versus Bismuth-Based Quadruple Therapy for H. pylori: A GRADE-Assessed Meta-Analysis with Trial Sequential Analysis (Navabi S et al.; Tu1222)
• Vonoprazan Based Therapy Outperforms Proton Pump Inhibitor Regimens for H. pylori Eradication: A Review of Six Meta-Analyses (Chakinala R et al.; Tu1219)
• Simplicity Without Compromise: An Updated Meta-Analysis of Vonoprazan-Amoxicillin Dual Therapy Versus Bismuth Quadruple Therapy for H. pylori Eradication (Zahid M et al.; Tu1205)
• Efficacy and Safety of Vonoprazan-Amoxicillin Dual Therapy Versus Bismuth Quadruple Therapy for H. pylori: A Systematic Review and Meta-Analysis (Haider A et al.; Tu1204)
• Comparative Efficacy and Safety of Vonoprazan Triple Therapy Versus PPI and Bismuth Based Quadruple Therapy for H. pylori: A Systematic Review and Meta-Analysis (Gundapaneni S et al.; Tu1200)
• Ten Versus Fourteen Days of Vonoprazan-Based Therapy for H. pylori: A Systematic Review and Meta-Analysis (Alsaleh T et al.; Tu1211)
• Efficacy and Safety of 14-Day Bismuth-Containing Quadruple Therapy with Low-Dose Vonoprazan Versus Esomeprazole for H. pylori Eradication: A Real-World Multicenter Study (Lin H et al.; Tu1213)
• Efficacy and Safety of Vonoprazan Dual Versus Quadruple Therapy for H. pylori Second-Line Treatment: A Real-World Study (Li P et al.; Tu1209)
• P-CAB/Minocycline/Furazolidone/Bismuth Quadruple Regimen for Refractory H. pylori Infection: A Multicenter Study (Li P et al.; Tu1199)
• Vonoprazan Plus High-Dose Amoxicillin Dual Therapy Versus PPI-Based Low-Dose Amoxicillin Quadruple Therapy for H. pylori: A Systematic Review and Meta-Analysis (Patel R et al.; Tu1220)
• Vonoprazan-Tetracycline Dual Therapy as a Simplified Rescue Regimen for Helicobacter Pylori: A Randomized Non-Inferiority Trial (Li J et al.; Poster 437)
• Transforming Amoxicillin Therapy into a Grade-A Eradication Regimen with Vonoprazan and Bismuth: A Multicenter Randomized Trial (Hsu P et al.; Poster 861)
  
  
  
  

Vonoprazan Use Post Endoscopic Submucosal Dissection

• Potassium-Competitive Acid Blockade After ESD: Does Vonoprazan Outperform PPIs? A Systematic Review and Meta-Analysis (Ginnaram S et al.; Su1226)
• Vonoprazan Versus Proton Pump Inhibitors for Prevention of Delayed Bleeding After Endoscopic Submucosal Dissection: A Systematic Review and Meta-Analysis (Singh S et al.; Sa2164)
  
  
  
  

Phathom-Sponsored Research on Vonoprazan:

• Assessment of Heartburn and Regurgitation in Symptomatic Non-Erosive Gastroesophageal Reflux Disease Patients on Vonoprazan: Exploratory Analysis of PAGI-SYM [Poster of Distinction] (Fass R et al.; Tu1159)
• Patient Reported Outcomes, Patient Experience, and Treatment Satisfaction with Prescription Treatments for Gastroesophageal Reflux Disease: A Real-World Survey of U.S. Adults (Shaheen N et al.; Tu1164)
• A Phase 1, Open-Label Study to Evaluate Vonoprazan Concentrations in Breast Milk of Healthy Lactating Women Receiving Vonoprazan 20 mg QD or BID (Chang YM et al.; Su1272)
  
  
  
  

About VOQUEZNA^® (vonoprazan)

VOQUEZNA^® (vonoprazan) tablets contain vonoprazan, an oral small molecule potassium-competitive acid blocker (PCAB). PCABs are a novel class of medicines that block acid secretion in the stomach. VOQUEZNA is approved in the U.S. for the treatment of adults with Erosive Esophagitis, also known as Erosive GERD, the relief of heartburn associated with Erosive GERD, the relief of heartburn associated with Non-Erosive GERD, and for the treatment of H. pylori infection in combination with either amoxicillin or amoxicillin and clarithromycin. Any other uses of vonoprazan as described in the research presented at DDW are investigational in the U.S. and Phathom makes no representations concerning the safety or efficacy of such investigational uses. Phathom in-licensed the U.S. rights to vonoprazan from Takeda, which markets the product in Japan and numerous other countries in Asia and Latin America.

INDICATIONS AND USAGE

VOQUEZNA^® (vonoprazan) is a potassium-competitive acid blocker (PCAB) indicated in adults:

• for the healing of all grades of Erosive Esophagitis (Erosive Gastroesophageal Reflux Disease or Erosive GERD) and relief of heartburn associated with Erosive GERD.
• to maintain healing of all grades of Erosive GERD and relief of heartburn associated with Erosive GERD.
• for the relief of heartburn associated with Non-Erosive GERD.
• in combination with amoxicillin and clarithromycin for the treatment of Helicobacter pylori (H. pylori)
• infection.
• in combination with amoxicillin for the treatment of H. pylori infection.
  
  
  
  

IMPORTANT SAFETY INFORMATION

CONTRAINDICATIONS

VOQUEZNA is contraindicated in patients with a known hypersensitivity to vonoprazan or any component of VOQUEZNA, or in patients receiving rilpivirine-containing products.

For information about contraindications of antibacterial agents (clarithromycin and amoxicillin) indicated in combination with VOQUEZNA, refer to the Contraindications section of the corresponding prescribing information.

WARNINGS AND PRECAUTIONS

Presence of Gastric Malignancy: In adults, symptomatic response to therapy with VOQUEZNA does not preclude the presence of gastric malignancy. Consider additional follow-up and diagnostic testing in patients who have a suboptimal response or an early symptomatic relapse after completing treatment with VOQUEZNA. In older patients, also consider endoscopy.

Acute Tubulointerstitial Nephritis: Acute tubulointerstitial nephritis (TIN) has been reported with VOQUEZNA. If suspected, discontinue VOQUEZNA and evaluate patients with suspected acute TIN.

Clostridioides difficile-Associated Diarrhea: Published observational studies suggest that proton pump inhibitors (PPIs) may be associated with an increased risk of Clostridioides difficile-associated diarrhea (CDAD), especially in hospitalized patients. VOQUEZNA may also increase the risk of CDAD. Consider CDAD in patients with diarrhea that does not improve. Use the shortest duration of VOQUEZNA appropriate to the condition being treated.

CDAD has been reported with use of nearly all antibacterial agents. For more information specific to antibacterial agents (clarithromycin and amoxicillin) indicated for use in combination with VOQUEZNA, refer to Warnings and Precautions section of the corresponding prescribing information.

Bone Fracture: Several published observational studies suggest that PPI therapy may be associated with an increased risk for osteoporosis-related fractures of the hip, wrist, or spine, especially in patients receiving high dose (multiple daily doses) and long-term therapy (a year or longer). Bone fracture, including osteoporosis-related fracture, has also been reported with vonoprazan. Use the shortest duration of VOQUEZNA appropriate to the condition being treated. Patients at risk for osteoporosis-related fractures should be managed according to the established treatment guidelines.

Severe Cutaneous Adverse Reactions (SCAR): Severe cutaneous adverse reactions, including Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) have been reported with VOQUEZNA. Discontinue VOQUEZNA at the first signs or symptoms of SCAR or other signs of hypersensitivity and consider further evaluation.

Vitamin B12 (Cobalamin) Deficiency: Long-term use of acid-suppressing drugs can lead to malabsorption of Vitamin B12 caused by hypo- or achlorhydria. Vitamin B12 deficiency has been reported postmarketing with vonoprazan. If clinical symptoms consistent with vitamin B12 deficiency are observed in patients treated with VOQUEZNA, consider further workup.

Hypomagnesemia and Mineral Metabolism: Hypomagnesemia has been reported postmarketing with vonoprazan. Hypomagnesemia may lead to hypocalcemia and/or hypokalemia and may exacerbate underlying hypocalcemia in at-risk patients.

Consider monitoring magnesium levels prior to initiation of VOQUEZNA and periodically in patients expected to be on prolonged treatment, in patients taking drugs that may have increased toxicity in the presence of hypomagnesemia or drugs that may cause hypomagnesemia. Treatment of hypomagnesemia may require magnesium replacement and discontinuation of VOQUEZNA.

Consider monitoring magnesium and calcium levels prior to initiation of VOQUEZNA and periodically while on treatment in patients with a preexisting risk of hypocalcemia. Supplement with magnesium and/or calcium, as necessary. If hypocalcemia is refractory to treatment, consider discontinuing VOQUEZNA.

Interactions with Diagnostic Investigations for Neuroendocrine Tumors: Serum chromogranin A (CgA) levels increase secondary to drug-induced decreases in gastric acidity. The increased CgA level may cause false positive results in diagnostic investigations for neuroendocrine tumors. Temporarily discontinue VOQUEZNA treatment at least 4 weeks before assessing CgA levels and consider repeating the test if initial CgA levels are high.

Fundic Gland Polyps: Use of VOQUEZNA is associated with a risk of fundic gland polyps that increases with long-term use, especially beyond one year. Fundic gland polyps have been reported with vonoprazan in clinical trials and during postmarketing use with PPIs. Most patients who developed fundic gland polyps were asymptomatic and fundic gland polyps were identified incidentally on endoscopy. Use the shortest duration of VOQUEZNA appropriate to the condition being treated.

ADVERSE REACTIONS:

Healing of Erosive GERD: The most common adverse reactions (≥2% of patients in the VOQUEZNA arm) include gastritis (3%), diarrhea (2%), abdominal distention (2%), abdominal pain (2%), and nausea (2%).

Maintenance of Healed Erosive GERD: The most common adverse reactions (≥3% of patients in the VOQUEZNA arm) include gastritis (6%), abdominal pain (4%), dyspepsia (4%), hypertension (3%), and urinary tract infection (3%).

Relief of Heartburn Associated with Non-Erosive GERD: The most common adverse reactions (≥2% of patients in the VOQUEZNA arm) include abdominal pain (2%), constipation (2%), diarrhea (2%), nausea (2%), and urinary tract infection (2%).

Treatment of H. Pylori Infection (VOQUEZNA and Amoxicillin): The most common adverse reactions (≥2% in any treatment arm) include diarrhea (5%), abdominal pain (3%), vulvovaginal candidiasis (2%), nasopharyngitis (2%), dysgeusia (1%), headache (1%), and hypertension (1%).

Treatment of H. Pylori Infection (VOQUEZNA, Amoxicillin and Clarithromycin): The most common adverse reactions (≥2% in any treatment arm) include dysgeusia (5%), diarrhea (4%), vulvovaginal candidiasis (3%), headache (3%), abdominal pain (2%), hypertension (2%), and nasopharyngitis (<1%).

For more information on adverse reactions and laboratory changes with amoxicillin or clarithromycin, refer to Adverse Reactions section of the corresponding prescribing information.

DRUG INTERACTIONS

VOQUEZNA has the potential for clinically important drug interactions, including interactions with drugs dependent on gastric pH for absorption, drugs that are substrates for certain CYP enzymes, and some diagnostic tests. Avoid concomitant use of VOQUEZNA with atazanavir or nelfinavir. See full Prescribing Information for more details about important drug interactions. Consult the labeling of concomitantly used drugs to obtain further information about interactions with vonoprazan.

For information about drug interactions, contraindications, and warnings and precautions of antibacterial agents (amoxicillin or clarithromycin) indicated in combination with VOQUEZNA, refer to their corresponding prescribing information.

USE IN SPECIFIC POPULATIONS

Pregnancy: There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to VOQUEZNA during pregnancy. Healthcare providers are encouraged to register patients by calling 1-866-609-1612 or visiting https://voqueznapregnancyregistry.com/.

Lactation: There are no data on the effects of vonoprazan on the breastfed child or the effects on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for VOQUEZNA and any potential adverse effects on the breastfed child from VOQUEZNA or from the underlying maternal condition.

Renal Impairment: For the healing of Erosive GERD, dosage reduction is recommended in patients with severe renal impairment (eGFR < 30 mL/min). Use of VOQUEZNA is not recommended for the treatment of H. pylori infection in patients with severe renal impairment.

Hepatic Impairment: For the healing of Erosive GERD, dosage reduction is recommended in patients with moderate to severe hepatic impairment (Child-Pugh Class B and C). Use of VOQUEZNA is not recommended for the treatment of H. pylori infection in patients with moderate to severe hepatic impairment.

You are encouraged to report suspected adverse reactions by contacting Phathom Pharmaceuticals at 1-888- 775-PHAT (7428) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Please click here to see full Prescribing Information for VOQUEZNA.

About Phathom Pharmaceuticals, Inc.

Phathom Pharmaceuticals is a biopharmaceutical company focused on the development and commercialization of novel treatments for gastrointestinal diseases. Phathom has in-licensed the exclusive rights to vonoprazan, a first-in-class potassium-competitive acid blocker (PCAB), for the U.S., Europe and Canada. Phathom currently markets vonoprazan in the United States as VOQUEZNA^® (vonoprazan) tablets for the relief of heartburn associated with Non-Erosive GERD in adults, the healing and maintenance of healing of Erosive GERD in adults and relief of associated heartburn, and as part of VOQUEZNA^® TRIPLE PAK^® (vonoprazan tablets, amoxicillin capsules, clarithromycin tablets) and VOQUEZNA^® DUAL PAK^® (vonoprazan tablets, amoxicillin capsules) for the treatment of H. pylori infection in adults. For more information about Phathom, visit the company's website at www.phathompharma.com follow on LinkedIn and X.

About DDW

Digestive Disease Week^® (DDW) is the largest international gathering of physicians, researchers, and academics in the fields of gastroenterology, hepatology, endoscopy, and gastrointestinal surgery. Jointly sponsored by the American Association for the Study of Liver Diseases (AASLD), the American Gastroenterological Association (AGA), the American Society for Gastrointestinal Endoscopy (ASGE), and the Society for Surgery of the Alimentary Tract (SSAT), DDW is an in-person and online meeting.

Forward-Looking Statements

This press release contains forward-looking statements, including without limitation statements regarding: the significance, interpretation and potential implications of data presented at DDW 2026; the scientific interest in vonoprazan and the potassium-competitive acid blocker (PCAB) class; the potential efficacy, safety and tolerability profile of VOQUEZNA® (vonoprazan); and the relevance and applicability of analyses, meta-analyses, real-world studies, post hoc analyses and investigator-initiated research discussed in this press release. These statements involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements, including the risk that: the data, analyses and other information presented at DDW 2026 may not be predictive or indicative of future research findings, clinical outcomes or real-world results; exploratory analyses, post hoc analyses, meta-analyses, retrospective studies and investigator-initiated research are subject to inherent limitations and may be interpreted differently following additional review, analysis or peer review; additional data or analyses may alter the interpretation or significance of results discussed in this press release; regulatory review may differ from or not support the conclusions suggested by the data discussed in this press release or future data, analyses; and market acceptance for VOQUEZNA from healthcare professionals, patients and payors in the indications for which it is approved may be lower than we anticipate. For additional discussion of these and other risks, see the risk disclosure in our filings with the Securities and Exchange Commission (SEC), including our Annual Report on Form 10-K and any subsequent filings with the SEC. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof, and we undertake no obligation to revise or update this press release to reflect events or circumstances after the date hereof. All forward-looking statements are qualified in their entirety by this cautionary statement, which is made under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995

MEDIA CONTACT

Nick Benedetto

1-877-742-8466

media@phathompharma.com

INVESTOR CONTACT

Eric Sciorilli

1-877-742-8466

ir@phathompharma.com

© 2026 Phathom Pharmaceuticals. All rights reserved.

VOQUEZNA, VOQUEZNA DUAL PAK, VOQUEZNA TRIPLE PAK, Phathom Pharmaceuticals, and their respective logos are registered trademarks of Phathom Pharmaceuticals, Inc.

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