Exhibit 99.1 Phathom Pharmaceuticals Reports First Quarter 2024 Financial Results and Provides Business Update • Over 17,500 total prescriptions for VOQUEZNA® products have been dispensed, launch-to-date, a 361% increase since last quarterly report • Net revenues of $1.9 million reported for the first full quarter of launch • Cigna Healthcare recently added VOQUEZNA tablets to its formularies, broadening coverage to approximately 48% of all U.S. commercial lives • National direct-to-consumer campaign, “VOQU ...

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, 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 Juri ...

Phathom Pharmaceuticals, Inc. (NASDAQ:PHAT) Q4 2023 Earnings Conference Call March 7, 2024 8:30 AM ET Company Participants 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. Wainw ...

Exhibit 99.1 Phathom Pharmaceuticals Reports Fourth Quarter and Full Year 2023 Financial Results and Provides Business Update • Launched VOQUEZNA® (vonoprazan) tablets in November 2023 for the treatment of Erosive GERD (gastroesophageal reflux disease), achieving net revenues of $0.7 million for the fourth quarter • Early physician prescribing demonstrates strong demand for VOQUEZNA • Secured expanded commercial coverage for VOQUEZNA with a top U.S. pharmacy benefit manager (PBM), growing commercial access ...

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) Delaware 82-4151574 (State or other juris ...

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 ...