Phathom Pharmaceuticals to Present New Data and Analyses for VOQUEZNA® (vonoprazan) at the American College of Gastroenterology (ACG) 2026 Annual Scientific Meeting

Three scientific presentations will highlight new analyses of VOQUEZNA^® (vonoprazan) in GERD, including real-world patient characteristics, efficacy across BMI subgroups, and cost-effectiveness in Erosive Esophagitis

FLORHAM PARK, N.J., Oct. 08, 2026 (GLOBE NEWSWIRE) -- Phathom Pharmaceuticals, Inc. (Nasdaq: PHAT), a biopharmaceutical company focused on developing and commercializing novel treatments for gastrointestinal (GI) diseases, today announced its participation in the American College of Gastroenterology (ACG) 2026 Annual Scientific Meeting, being held October 9-14 in Nashville, Tennessee.

Phathom will present three scientific posters featuring new data and analyses for VOQUEZNA^® (vonoprazan) in Gastroesophageal Reflux Disease (GERD), including a post hoc analysis of VOQUEZNA efficacy in patients with Non-Erosive GERD across Body Mass Index (BMI) subgroups, a retrospective analysis of real-world patient characteristics, and a model examining the cost-effectiveness of VOQUEZNA compared with proton pump inhibitors (PPIs) in Erosive Esophagitis, or Erosive GERD. The Company will also host a Product Theater to highlight the clinical efficacy and safety profile of VOQUEZNA.

“ACG provides an important opportunity to continue advancing the scientific dialogue around GERD and share new insights with the GI community,” said Steve Basta, President and Chief Executive Officer of Phathom. “These analyses add to the growing body of data on VOQUEZNA and provide new perspectives relevant to its use in GERD. We look forward to discussing these findings with GI healthcare providers and hearing firsthand perspectives from clinicians and patients throughout the meeting.”

Phathom’s Presentations at ACG 2026:

Sunday, October 11, 2026

Vonoprazan Efficacy Across BMI Subgroups in Non-Erosive Reflux Disease
- Poster: P0624
- Time: 3:30 PM – 7:00 PM CDT
- Presenter: Catiele Antunes, MD, Assistant Professor of Medicine and Director of the Refractory GERD Clinic at Yale School of Medicine

Monday, October 12, 2026

Characteristics of US Patients With Gastroesophageal Reflux Disease (GERD) Taking Vonoprazan or a Prescription Proton Pump Inhibitor (PPI)
- Poster: P2921
- Time: 10:30 AM – 4:15 PM CDT
- Presenter: Nicholas J. Shaheen, MD, MPH, Chief of the Division of Gastroenterology and Hepatology and Bozymski-Heizer Distinguished Professor of Medicine at the UNC School of Medicine

VOQUEZNA^® (vonoprazan) Product Theater: Beyond the Data: From Clinical Cases to Patient Perspectives
- Location: Booth #117 – ACG Product Theater
- Time: 3:45 PM CDT
- Presenters: John E. Pandolfino, MD, MSCI, Chief of Gastroenterology and Hepatology and Hans Popper Professor of Medicine at Northwestern University Feinberg School of Medicine; and a Patient Speaker

Tuesday, October 13, 2026

Cost-Effectiveness of Vonoprazan Versus Proton Pump Inhibitors in Adults With Erosive Esophagitis in the United States: A Markov Model of Lifetime Outcomes
- Poster: P5160
- Time: 10:30 AM – 4:00 PM CDT
- Presenter: Nicholas J. Shaheen, MD, MPH, Chief of the Division of Gastroenterology and Hepatology and Bozymski-Heizer Distinguished Professor of Medicine at the UNC School of Medicine

Attendees can also visit Phathom’s Medical Affairs and Commercial teams on the exhibit floor at Booth 323.

About VOQUEZNA
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.

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.

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.

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%).

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.

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).

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).

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 for 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 the 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 and follow on LinkedIn and X.

Forward-Looking Statement
This press release contains forward-looking statements, including statements regarding Phathom’s planned participation in and presentations at the ACG 2026 Annual Scientific Meeting. These forward-looking statements are subject to certain risks and uncertainties that could cause actual results or events to differ materially from those expressed or implied by such statements, including risks and uncertainties associated with the Company’s business described under the heading “Risk Factors” in Phathom’s Annual Report on Form 10-K for the year ended December 31, 2025, as updated by Phathom’s subsequent filings with the U.S. Securities and Exchange Commission. Any forward-looking statements in this press release speak only as of the date of this press release, and Phathom undertakes no obligation to update such statements, except as required by law.

MEDIA CONTACT
Nick Benedetto
1-877-742-8466
media@phathompharma.com

INVESTOR CONTACT
Eric Sciorilli
1-877-742-8466
ir@phathompharma.com

09/26 US-VPZ-26-0310