Phathom Pharmaceuticals Reports First Quarter 2023 Results

Phathom Pharmaceuticals Reports First Quarter 2023 Results

FLORHAM PARK, N.J., May 10, 2023 Phathom Pharmaceuticals, Inc. (Nasdaq: PHAT), a biopharmaceutical company focused on developing and

commercializing novel treatments for gastrointestinal diseases, today reported financial results for the first quarter of 2023 and provided updates on recent regulatory progress.

This quarter, we made remarkable progress advancing mission-critical priorities that position Phathom to potentially deliver vonoprazan to patients

suffering from Erosive GERD and H. pylori infection before year end, said Terrie Curran, President and Chief Executive Officer of Phathom. Our ongoing stability program for the minor drug product reformulation continues to

demonstrate effective control of the N-nitroso-vonoprazan (NVP) impurity and confirms our confidence that our planned NDA resubmission will address the sole deficiency cited in the FDA s complete response letters. Building on this

positive momentum, our commercial team continues to prepare for a planned fourth quarter commercial launch and we remain engaged with payers, healthcare providers, and key opinion leaders to capitalize on the blockbuster potential of our first-in-class therapy.

Clinical, Regulatory, and Business Updates:

First Quarter 2023 Financial Results:

About Phathom Pharmaceuticals, Inc.

Pharmaceuticals is a biopharmaceutical company focused on the development and commercialization of novel treatments for gastrointestinal diseases. Phathom has in-licensed the exclusive rights in the United

States, Europe, and Canada to vonoprazan, a first-in-class potassium-competitive acid blocker (PCAB). For more information about Phathom, visit the Company s

website at www.phathompharma.com and follow the Company on LinkedIn and Twitter.

Forward Looking Statements

Phathom cautions you that statements contained in this press release regarding matters that are not historical facts are forward-looking statements. These

statements are based on the Company s current beliefs and expectations. Such forward-looking statements include, but are not limited to, statements regarding Phathom s expectations of generating stability data necessary to support the

proposed shelf life of vonoprazan; the expected timing of resubmission of the Erosive GERD NDA; the potential approval of its Erosive GERD NDA and post approval supplements for its H. pylori NDAs, and anticipated product launches in H.

pylori and Erosive GERD; and that Phathom will have sufficient capital to fund operations through the end of 2024. The inclusion of forward-looking statements should not be regarded as a representation by Phathom that any of its plans will be

achieved. Actual results may differ from those set forth in this press release due to the risks and uncertainties inherent in Phathom s business, including, without limitation: Phathom may be unable to generate the required data to meet the

acceptable intake of its nitrosamine impurity, or may be unable to reduce the impurity to an acceptable level throughout the shelf life of the product, to obtain approval its Erosive GERD NDA or to bring vonoprazan to market for patients with

Erosive GERD, if approved, or for patients with H. pylori; future nitrosamine data may be inconsistent with data generated to date; the FDA may not accept for review the Erosive GERD NDA even after we have submitted the NDA; risks associated

with product manufacturing or formulation changes required to be made in connection with achieving the acceptable daily intake limit of the nitrosamine detected in vonoprazan drug product; the FDA may disagree that the existing safety and efficacy

data, together with additional data, is sufficient to approve the erosive esophagitis NDA or supplements to the H. pylori NDAs; the inherent risks of clinical development of vonoprazan; Phathom s dependence on third parties in connection

with product manufacturing, research and preclinical and clinical testing; regulatory developments in the United States and foreign countries; unexpected adverse side effects or inadequate efficacy of vonoprazan that may limit its development,

regulatory approval and/or commercialization, or may result in recalls or product liability claims; Phathom s ability to access additional capital under its term loan facility and royalty interest finance agreements is subject to certain

conditions; Phathom s ability to obtain and maintain intellectual property protection for vonoprazan; Phathom s ability to comply with its license agreement with Takeda; and other risks described in the Company s prior press releases

and the Company s filings with the Securities and Exchange Commission (SEC), including under the heading Risk Factors in the Company s Annual Report on Form 10-K and any subsequent

filings with the SEC. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof, and Phathom undertakes no obligation to update such statements to reflect events that occur or

circumstances that exist after the date hereof. All forward-looking statements are qualified in their entirety by this cautionary statement, which is made under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995.

Selected Condensed Balance Sheets

Statements of Operations and Comprehensive Loss

thousands, except share and per share amounts)