UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-39094 PHATHOM PHARMACEUTICALS, INC. (Exact name of Registrant as specified in its charter) (State or Other Jurisdiction of Incorpora ...

| --- | |-----------------------------------------------------------------------| | | | Eric Sciorilli - Head of Investor Relations | | Terrie Curran - President & Chief Executive Officer | | Martin Gilligan - Chief Commercial Officer | | Molly Henderson - Chief Financial Officer | | Azmi Nabulsi - Chief Operating Officer | | Conference Call Participants | | Yatin Suneja - Guggenheim Joseph Stringer - Needham & Company | | Paul Choi - Goldman Sachs Umer Raffat - Evercore | | Matthew Caufield - H.C. Wainwrig ...

Exhibit 99.1 Phathom Pharmaceuticals Reports Fourth Quarter and Full Year 2023 Financial Results and Provides Business Update FLORHAM PARK, N.J., March 7, 2024 — Phathom Pharmaceuticals, Inc. (Nasdaq: PHAT), a biopharmaceutical company focused on developing and commercializing novel treatments for gastrointestinal diseases, today reported financial results for the fourth quarter and full year ended December 31, 2023, and provided recent business highlights. "Last year was transformative for Phathom, with ke ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission File Number: 001-39094 PHATHOM PHARMACEUTICALS, INC. (Exact name of Registrant as specified in its charter) (State or other jurisdiction of incorpora ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission File Number: 001-39094 PHATHOM PHARMACEUTICALS, INC. (Exact name of Registrant as specified in its charter) Delaware 82-4151574 (State or other jurisdicti ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to . Commission File Number: 001-39094 PHATHOM PHARMACEUTICALS, INC. (Exact name of Registrant as specified in its charter) Delaware 82-4151574 (State or other jurisdict ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year end ed December 31, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-39094 PHATHOM PHARMACEUTICALS, INC. (Exact name of Registrant as specified in its charter) Delaware 82-4151574 (State or Other Juri ...

Phathom. CHANGING THE LANDSCAPE IN GI Going beyond to advance treatments for patients with acid-related disorders CORPORATE OVERVIEW JANUARY 2021 Safe harbor statement This presentation contains forward-looking statements. All statements other than statements of historical facts contained in this presentation, including statements regarding our future results of operations and financial position, business strategy, prospective products, product approvals, research and development costs, timing and likelihoo ...