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, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 | | | Commission file number: 001-39094 PHATHOM PHARMACEUTICALS, INC. (Exact name of Registrant as specified in its charter) Delaware 82-4151574 (State or Other Jurisdiction of Incorporation or ...

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, 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 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, 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 jurisdicti ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 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 . WASHINGTON, D.C. 20549 FORM 10-Q 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 ended December 31, 2021 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 ...

WASHINGTON, D.C. 20549 FORM 10-Q UNITED STATES SECURITIES AND EXCHANGE COMMISSION Delaware 82-4151574 (State or other jurisdiction of incorporation or organization) PHATHOM PHARMACEUTICALS, INC. 100 Campus Drive, Suite 102 Florham Park, New Jersey 07932 (Address of principal executive offices) (Zip Code) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2021 OR (Exact name of Registrant as specified in its charter) ☐ TRANSI ...

Financial Performance - Net loss for the six months ended June 30, 2021, was $71,395,000, compared to a net loss of $41,242,000 for the same period in 2020, indicating an increase in losses of approximately 73.2%[11] - The net losses for the six-month periods ended June 30, 2021, and 2020 were $71.4 million and $41.2 million, respectively, with an accumulated deficit of $456.9 million as of June 30, 2021[114] - For the six months ended June 30, 2021, total operating expenses were $68.9 million, an increase of $28.5 million from $40.4 million in the same period of 2020[127] - Research and development expenses for the six months ended June 30, 2021, were $42.2 million, up from $30.7 million in 2020, reflecting an increase of $11.5 million[127] - General and administrative expenses for the six months ended June 30, 2021, were $26.7 million, an increase of $17.0 million from $9.7 million in 2020[128] Assets and Liabilities - Total current assets decreased from $291,368,000 as of December 31, 2020, to $211,338,000 as of June 30, 2021, representing a decline of approximately 27.5%[9] - Total liabilities decreased from $100,840,000 as of December 31, 2020, to $82,451,000 as of June 30, 2021, a reduction of about 18.2%[9] - Total stockholders' equity decreased from $194,271,000 as of December 31, 2020, to $132,128,000 as of June 30, 2021, a decline of about 32.0%[9] - Cash and cash equivalents decreased from $287,496,000 at the beginning of the period to $209,669,000 at the end of the period, a decrease of about 27.1%[19] - As of June 30, 2021, the company had cash and cash equivalents of $210 million[134] Cash Flow - Net cash used in operating activities for the six months ended June 30, 2021, was $78,129,000, compared to $20,761,000 for the same period in 2020, indicating a significant increase in cash outflow[19] - The company reported a net decrease in cash of $77.8 million for the six months ended June 30, 2021, compared to a net increase of $3.5 million in the same period of 2020[146] - Net cash provided by financing activities for the six months ended June 30, 2021, was $516, primarily from the issuance of common stock from the exercise of stock options[149] Funding and Capital - The Company has incurred net losses and negative cash flows from operating activities since inception, with total net proceeds of approximately $191.5 million from the sale of 10,997,630 shares of common stock in its 2019 IPO[24] - In December 2020, the Company raised net proceeds of $88.6 million from the sale of 2,250,000 shares at a public offering price of $39.48 per share[24] - The company completed an underwritten public offering on December 16, 2020, selling 2,250,000 shares at $42.00 per share, generating net proceeds of $88.8 million after underwriting discounts[141] - The company expects existing cash and cash equivalents to be sufficient to meet anticipated cash requirements into the fourth quarter of 2022, supporting ongoing clinical trials[142] - The company anticipates future capital requirements will depend on various factors, including clinical trial costs and market acceptance of products[144] Research and Development - Research and development expenses for the three months ended June 30, 2021, were $21,597,000, up from $14,859,000 in the same period of 2020, reflecting a growth of about 45.3%[11] - Research and development expenses consist primarily of salaries, payroll taxes, employee benefits, and external costs related to clinical trials of vonoprazan[39] - The company has incurred approximately $61.8 million in research and development and general administrative activities during the first half of 2021[147] - The company expects to report top-line data from the PHALCON-EE trial in October 2021 and plans to submit regulatory filings for vonoprazan in September 2021[110] - The company has not generated any revenue and does not expect to do so from product sales until the development and regulatory approval of vonoprazan, which may take several years[115] Debt and Obligations - Total debt as of June 30, 2021, was $47,685,000 net of debt discount, which includes a current portion of $10,345,000 and a non-current portion of $39,655,000[70] - The Term Loans bear interest at a floating rate of the higher of the Wall Street Journal Prime rate plus 1.75% or 7.25%, with an interest-only payment period extended until December 31, 2021, contingent on positive clinical trial data[136] - The company has a final payment fee obligation of 8.25% of the original principal amount of the Term Loans, with prepayment options subject to fees[137] - Future minimum principal and interest payments under the Term Loans total $60.56 million, with $10.56 million attributed to interest and final payment fees[78] Stock and Equity - The weighted-average shares of common stock outstanding increased from 32,733,750 for the six months ended June 30, 2020, to 36,468,498 for the same period in 2021, an increase of approximately 11.1%[11] - The Company issued 1,084,000 shares of common stock to Takeda in connection with the Takeda License[81] - The Company has a total of 7,588,000 shares of common stock included in the calculation of basic weighted-average common shares outstanding due to the Takeda Warrant[49] - The Company granted 220,000 performance-based stock units in 2020, with an additional 109,050 granted in 2021, contingent on FDA approval milestones[90] - The Employee Stock Purchase Plan (ESPP) allows participants to purchase common stock through payroll deductions, with 858,783 shares remaining available for issuance as of June 30, 2021[93] Legal and Compliance - The company is not currently subject to any material legal proceedings, which could impact resources and costs[164] - There have been no changes in internal control over financial reporting that materially affected the company during the six months ended June 30, 2021[161] - The company has maintained effective disclosure controls and procedures, achieving a reasonable assurance level as evaluated by the principal executive officer and principal financial officer[160] - There have been no material changes to the risk factors disclosed in the previous Form 10-K[165] - The company has not engaged in any unregistered sales of equity securities[166]

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, 2021 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 ended December 31, 2020 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 ...

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 ...