Results of Operations and Financial Condition. On July 30, 2026, Phathom Pharmaceuticals, Inc. issued a press release announcing its financial results for the quarter ended June 30, 2026. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference. In accordance with General Instruction B.2 of Form 8-K, the information in this Current Report on Form 8-K, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities…

Other Events. On June 23, 2026, Phathom Pharmaceuticals, Inc. (“Phathom” or the “Company”) announced it has completed enrollment in its Phase 2 pHalcon-EoE-201 clinical trial evaluating VOQUEZNA ® (vonoprazan) tablets as an investigational treatment for eosinophilic esophagitis (“EoE”) in adults. The study has enrolled 95 patients at 41 U.S. sites. Topline results are anticipated in the fourth quarter 2026. The pHalcon-EoE-201 study is a two-part, randomized, double-blind, placebo-controlled…

Results of Operations and Financial Condition. On April 30, 2026, Phathom Pharmaceuticals, Inc. issued a press release announcing its financial results for the quarter ended March 31, 2026. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference. In accordance with General Instruction B.2 of Form 8-K, the information in this Current Report on Form 8-K, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securitie…

Results of Operations and Financial Condition. On February 26, 2026, Phathom Pharmaceuticals, Inc. issued a press release announcing its financial results for the quarter and year ended December 31, 2025. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference. In accordance with General Instruction B.2 of Form 8-K, the information in this Current Report on Form 8-K, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 o…

Other Events. On January 7, 2026, Phathom Pharmaceuticals, Inc. (“Phathom” or the “Company”) entered into an underwriting agreement (the “Underwriting Agreement”) with Guggenheim Securities, LLC and Cantor Fitzgerald & Co., as representatives of the several underwriters named therein (collectively, the “Underwriters”), relating to the issuance and sale of (i) 6,875,000 shares (the “Shares”) of the Company’s common stock, par value $0.0001 per share (the “Common Stock”), at an offering price t…

Results of Operations and Financial Condition. On January 7, 2026, Phathom Pharmaceuticals, Inc. issued a press release announcing certain preliminary unaudited financial results for the fourth quarter and full year ended December 31, 2025. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference. Pursuant to the rules and regulations of the SEC, the information provided in this

Other Events. On November 4, 2025, Phathom Pharmaceuticals, Inc. (“Phathom” or the “Company”) announced the first patient has been dosed in its Phase 2 pHalcon EoE-201 clinical trial evaluating VOQUEZNA ® (vonoprazan) tablets as an investigational treatment for eosinophilic esophagitis (“EoE”) in adults. Phathom’s Phase 2 EoE study is a two-part, randomized, double-blind, placebo-controlled study. The first part will enroll 80 adults with endoscopic-confirmed EoE and dysphagia, or trouble swa…

Results of Operations and Financial Condition. On October 30, 2025, Phathom Pharmaceuticals, Inc. issued a press release announcing its financial results for the quarter ended September 30, 2025. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference. In accordance with General Instruction B.2 of Form 8-K, the information in this Current Report on Form 8-K, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Sec…

Other Events. On October 25, 2025, Phathom Pharmaceuticals, Inc. (“Phathom” or the “Company”) announced that results of additional analyses from its pivotal Phase 3 pHalcon-NERD-301 trial evaluating VOQUEZNA ® (vonoprazan) tablets in patients with Non-Erosive Reflux Disease (“NERD”) have been published in the American Journal of Gastroenterology . The article, titled “ Vonoprazan Improves Nocturnal Gastroesophageal Reflux Symptoms in Non-Erosive Reflux Disease ” , underscores the significant…

Chief Financial and Business Officer — Sanjeev Narula: Sanjeev Narula was appointed as the Chief Financial and Business Officer of Phathom Pharmaceuticals, Inc.

Results of Operations and Financial Condition. On August 7, 2025, Phathom Pharmaceuticals, Inc. issued a press release announcing its financial results for the quarter ended June 30, 2025. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference. In accordance with General Instruction B.2 of Form 8-K, the information in this Current Report on Form 8-K, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities…

Other Events. On June 16, 2025, Phathom Pharmaceuticals, Inc. (“Phathom” or the “Company”), announced that the U.S. Food and Drug Administration (“FDA”) has updated the Approved Drug Products with Therapeutic Equivalence Evaluations (the “Orange Book”) to accurately reflect the full 10-year period of non-patent New Chemical Entity (“NCE”) exclusivity for VOQUEZNA (vonoprazan) 10 mg and 20 mg tablets. The corrected Orange Book listing confirms that VOQUEZNA is entitled to NCE regulatory exclus…

Other Events. As referenced above, on June 6, 2025, the FDA has approved the Citizen Petition and communicated its intention to correct the Orange Book to recognize the proper 10 years of New Chemical Entity exclusivity for VOQUEZNA® (vonoprazan) tablets, extending through May 3, 2032. Forward Looking Statements This report contains forward-looking statements. Investors are cautioned not to place undue reliance on these forward-looking statements, including statements about the timing of the…

Results of Operations and Financial Condition. On May 1, 2025, Phathom Pharmaceuticals, Inc. issued a press release announcing its financial results for the quarter ended March 31, 2025. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference. In accordance with General Instruction B.2 of Form 8-K, the information in this Current Report on Form 8-K, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities E…

Director — Theodore R. Schroeder: Appointment of Theodore R. Schroeder to the Board as a Class I director.

CEO — Terrie Curran: Terrie Curran resigned as CEO for personal reasons.

Results of Operations and Financial Condition. On March 6, 2025, Phathom Pharmaceuticals, Inc. issued a press release announcing its financial results for the quarter and year ended December 31, 2024. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference. In accordance with General Instruction B.2 of Form 8-K, the information in this Current Report on Form 8-K, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of th…

Other Events. On December 11, 2024, Phathom Pharmaceuticals, Inc. (“Phathom” or the “Company”), announced that it has submitted a Citizen Petition (“CP”) with the U.S. Food and Drug Administration (“FDA”). The petition formally requests correction of the Orange Book listings for VOQUEZNA (vonoprazan) 10 mg and 20 mg tablets to accurately reflect the full 10-year New Chemical Entity (“NCE”) exclusivity period until May 3, 2032. The update would align the VOQUEZNA tablets Orange Book listings t…

Results of Operations and Financial Condition. On November 7, 2024, Phathom Pharmaceuticals, Inc. issued a press release announcing its financial results for the quarter ended September 30, 2024. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference. In accordance with General Instruction B.2 of Form 8-K, the information in this Current Report on Form 8-K, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Sec…

Other Events. On August 19, 2024, Phathom Pharmaceuticals, Inc. (“Phathom” or the “Company”) entered into an underwriting agreement (the “Underwriting Agreement”) with Evercore Group L.L.C., Stifel, Nicolaus & Company, Incorporated and Guggenheim Securities, LLC, as representatives of the several underwriters named therein (collectively, the “Underwriters”), relating to the issuance and sale of (i) 8,695,652 shares (the “Shares”) of the Company’s common stock, par value $0.0001 per share (the…

Results of Operations and Financial Condition. On August 8, 2024, Phathom Pharmaceuticals, Inc. issued a press release announcing its financial results for the quarter ended June 30, 2024. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference. In accordance with General Instruction B.2 of Form 8-K, the information in this Current Report on Form 8-K, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities…

Other Events. On July 18, 2024, Phathom Pharmaceuticals, Inc. (“Phathom” or the “Company”), announced that the U.S. Food and Drug Administration (“FDA”) has approved VOQUEZNA ® (vonoprazan) 10 mg tablets for the relief of heartburn associated with Non-Erosive Gastroesophageal Reflux Disease (“Non-Erosive GERD”) in adults. Non-Erosive GERD represents a substantial segment of the U.S. GERD population, affecting millions of individuals suffering from frequent heartburn. This is the third FDA app…

Results of Operations and Financial Condition. On May 9, 2024, Phathom Pharmaceuticals, Inc. issued a press release announcing its financial results for the quarter ended March 31, 2024. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference. In accordance with General Instruction B.2 of Form 8-K, the information in this Current Report on Form 8-K, including Exhibit 99.1, shall not be deemed “filed” for purposes of Section 18 of the Securities E…

Results of Operations and Financial Condition. On March 7, 2024, Phathom Pharmaceuticals, Inc. (the “Company”) issued a press release announcing its financial results for the quarter and year ended December 31, 2023. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference. In accordance with General Instruction B.2 of Form 8-K, the information in this Current Report on Form 8-K, including Exhibit 99.1, shall not be deemed “filed” for purposes of…

SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. PHATHOM PHARMACEUTICALS, INC. Date: December 14, 2023 By: /s/ Larry Miller Larry Miller General Counsel and Secretary