Phathom Pharmaceuticals, Inc.

Bu siness Overview We are a commercial-stage biopharmaceutical company focused on commercializing and developing novel treatments for gastrointestinal, or GI, diseases. Our approved products, VOQUEZNA , VOQUEZNA DUAL PAK and VOQUEZNA TRIPLE PAK , contain vonoprazan, an oral small molecule potassium-competitive acid blocker, or PCAB. PCABs are a novel class of molecules that block acid secretion in the stomach. VOQUEZNA is the only PCAB currently approved for marketing and sale in the United States. We began U.S. commercialization of VOQUEZNA for the treatment of erosive gastroesophageal reflux disease, or Erosive GERD, and Helicobacter pylori, or H. pylori , infection, and VOQUEZNA DUAL PAK and VOQUEZNA TRIPLE PAK for the treatment of H. pylori infection, in November 2023. The U.S. Food and Drug Administration, or FDA, approved VOQUEZNA for the relief of heartburn associated with Non-Erosive GERD, the largest category of GERD, in July 2024. Vonoprazan was originally developed by Takeda Pharmaceutical Company Limited, or Takeda, and is marketed in multiple countries outside the United States. We licensed U.S., European and Canadian rights to vonoprazan from Takeda in 2019. We are independently commercializing VOQUEZNA, VOQUEZNA DUAL PAK and VOQUEZNA TRIPLE PAK in the United States. During the year ended December 31, 2025, we generated increased revenues from sales of our VOQUEZNA products compared to the prior year, reflecting continued execution of our U.S. commercial strategy. The majority of our 2025 revenue was derived from sales of VOQUEZNA.