Summary of Significant Accounting Policies (Policies)

9 Months Ended

Sep. 30, 2025

Iterum Therapeutics plc (the Company) was incorporated under the laws of the Republic of Ireland in June 2015 as a limited company and re-registered as a public limited company on March 20, 2018. The Company maintains its registered office at 25 North Wall Quay, Dublin 1, D01 H104, Ireland. The Company commenced operations in November 2015. The Company licensed global rights to its novel anti-infective compound, sulopenem, from Pfizer Inc. (Pfizer). The Company is dedicated to maximizing the commercial potential of ORLYNVAH™ (sulopenem etzadroxil and probenecid), the first oral branded penem available in the United States and potentially the first and only oral and intravenous (IV) branded penem available globally and is focused on delivering differentiated anti-infectives aimed at combating the global crisis of multi-drug resistant pathogens to significantly improve the lives of people affected by serious and life-threatening diseases around the world. The Company is advancing the development of its first compound, sulopenem, a novel penem anti-infective compound, with an oral formulation and IV formulation. Sulopenem has demonstrated potent in vitro activity against a wide variety of gram-negative, gram-positive and anaerobic bacteria resistant to other antibiotics. In October 2024, the Company received approval from the United Sates Food and Drug Administration (FDA) of its New Drug Application for ORLYNVAH™ (oral sulopenem) for the treatment of uUTIs caused by the designated microorganisms Escherichia coli, Klebsiella pneumoniae, or Proteus mirabilis in adult women with limited or no alternative oral antibacterial treatment options. The Company commercially launched ORLYNVAH™ into the community market in the United Sates in August 2025 and expects modest sales in 2025 during the early stages of its commercialization efforts.

The Company is continuing to build its commercial capabilities and infrastructure to continue to support the launch of ORLYNVAH™ in the United States. In June 2025, the Company's subsidiary, Iterum Therapeutics US Limited (ITUS), entered into a Product Commercialization Agreement (the EVERSANA Agreement) with EVERSANA Life Science Services, LLC (EVERSANA) for the commercialization of ORLYNVAHTM. Pursuant to the EVERSANA Agreement, EVERSANA provides sales and commercial operations services to ITUS in the United States, as well as the provision of marketing, logistics, channel management, regulatory, medical affairs and other services related to the commercialization of ORLYNVAHTM in the United States.

Liquidity and Going Concern

Since inception, the Company has devoted substantially all of its efforts to research and development, recruiting management and technical staff, raising capital, and conducting pre-commercialization and commercialization activities. The Company began commercial operations in August 2025 and therefore has limited net product sales. The Company has financed its operations through the issuance of ordinary and convertible preferred shares, debt raised under a financing arrangement with Silicon Valley Bank (SVB) including the Paycheck Protection Program loan (PPP loan), a sub-award from the Trustees of Boston University under the Combating Antibiotic Resistant Bacteria Biopharmaceutical Accelerator (CARB-X) program and the proceeds of a private placement (Private Placement) and subsequent rights offering (the 2020 Rights Offering) pursuant to which its wholly owned subsidiary, Iterum Therapeutics Bermuda Limited (Iterum Bermuda) issued and sold approximately $51,808 aggregate principal amount of 6.500% Exchangeable Senior Subordinated Notes (Exchangeable Notes) and $104 aggregate principal amount of Limited Recourse Royalty-Linked Subordinated Notes (the RLNs and, together with the Exchangeable Notes, the Securities), which Securities were sold in units consisting of an Exchangeable Note in the original principal amount of $1,000 and 50 RLNs (the Units). Beginning on January 21, 2021 through January 31, 2025, certain noteholders of $40,691 aggregate principal amount of Exchangeable Notes completed a non-cash exchange of their notes, including accrued and unpaid interest of $3,071, for an aggregate of 3,760,155 of the Company’s ordinary shares. On January 31, 2025, the Exchangeable Notes matured and Iterum Bermuda repaid in full to the holders thereof an aggregate principal amount of $11,117 together with accrued interest of $3,628.

The Company is subject to risks and uncertainties common to early-stage companies in the pharmaceutical industry, including, but not limited to, the ability to secure additional capital to fund operations, failure to successfully develop and commercialize its product candidates, development by competitors of new technological innovations, dependence on key personnel, protection of proprietary technology and compliance with government regulations.

Even with receipt of FDA approval and the commercial launch of ORLYNVAHTM, it is uncertain when, if ever, the Company will realize significant revenue from product sales.

The accompanying condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) and include the accounts of the Company and its subsidiaries.

The Company filed a universal shelf registration statement on Form S-3 with the Securities and Exchange Commission (SEC), which was declared effective on October 17, 2022 (File No. 333-267795), and pursuant to which the Company registered for sale up to $100,000 of any combination of debt securities, ordinary shares, preferred shares, subscription rights, purchase contracts, units and/or warrants from time to time and at prices and on terms that the Company may determine. On October 7, 2022, the Company entered into a sales agreement with HC Wainwright (the Sales Agreement), as agent, pursuant to which it could offer and sell ordinary shares, nominal value $0.01 per ordinary share (the ordinary shares) for aggregate gross sales proceeds of up to $16,000 (subject to the availability of ordinary shares), from time to time through HC Wainwright by any method permitted that is deemed to be an “at the market offering” as defined in Rule 415(a)(4) promulgated under the Securities Act of 1933, as amended (the Securities Act). On

December 10, 2024, the Company filed a prospectus supplement with the SEC pursuant to which it may offer and sell ordinary shares having an aggregate offering price of up to an additional $25,000 through HC Wainwright pursuant to the Sales Agreement.

On August 9, 2024, the Company completed a rights offering (the 2024 Rights Offering) in which it sold an aggregate of 6,121,965 units (2024 Units) at a subscription price of $1.21 per whole 2024 Unit, consisting of (a) one ordinary share, (b) a warrant to purchase 0.50 ordinary shares, at an exercise price of $1.21 per whole ordinary share from the date of issuance through its expiration one year from the date of issuance (the 1-year warrants) and (c) a warrant to purchase one ordinary share, at an exercise price of $1.21 per whole ordinary share from the date of issuance through its expiration five years from the date of issuance (the 5-year warrants and, together with the 1-year warrants, the warrants). The Company's net proceeds from the 2024 Rights Offering, after deducting dealer-manager fees and other offering expenses payable by the Company, were $5,430. The warrants are exercisable upon issuance at a price of $1.21 per ordinary share. The 1-year warrants expired on August 9, 2025 and the 5-year warrants will expire on August 9, 2029.

The Company filed a universal shelf registration statement on Form S-3 with the SEC, which was declared effective on February 19, 2025 (File No. 333-284774), and pursuant to which the Company registered for sale up to $150,000 of any combination of debt securities, ordinary shares, preferred shares, subscription rights, purchase contracts, units and/or warrants from time to time and at prices and on terms that the Company may determine.

On April 28, 2025, the Company entered into a securities purchase agreement with an institutional investor (the April 2025 Registered Direct Offering) pursuant to which it issued and sold an aggregate of (i) 3,040,000 ordinary shares, at a purchase price of $0.90 per ordinary share, and (ii) pre-funded warrants to purchase up to an aggregate of 2,515,556 ordinary shares at a purchase price of $0.89 per pre-funded warrant. The Company's net proceeds from the April 2025 Registered Direct Offering, after deducting placement agent fees and offering expenses payable by the Company were $4,177. Upon closing, the pre-funded warrants became exercisable immediately at an exercise price of $0.01 per ordinary share, subject to adjustment in certain circumstances, and expire when exercised in full, subject to certain conditions. As of September 30, 2025, all pre-funded warrants issued in connection with the April 28, 2025 Offering had been exercised.

In accordance with Accounting Standards Update (ASU) 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (Subtopic 205-40), the Company has evaluated whether there are conditions and events, considered in aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year of the date of issue of these quarterly condensed consolidated financial statements.

The Company has funded its operations to date primarily with proceeds from the sale of preferred shares and ordinary shares, warrants, debt raised under its financing arrangement with SVB including the PPP loan (both of which have been repaid), payments received under the CARB-X program, proceeds from the Private Placement and 2020 Rights Offering and product sales. The Company has incurred operating losses since inception, including net losses of $20,379 and $18,192 for the nine months ended September 30, 2025 and 2024, respectively, and a net loss of $24,774 for the year ended December 31, 2024. The Company had an accumulated deficit of $506,451 as of September 30, 2025 and expects to continue to incur net losses for the foreseeable future. The Company’s future cash flows are dependent on key variables such as its ability to achieve its revenue growth from sales of ORLYNVAH™ in the United States and its ability to secure additional sources of funding in the form of public or private financing of debt or equity or collaboration agreements. Based on its available cash and cash equivalents, including amounts raised under the Sales Agreement with H.C. Wainwright & Co. LLC (HC Wainwright), as agent, subsequent to September 30, 2025 (see Note 19 – Subsequent Events), the Company does not have cash on hand to fund its current operations and capital expenditure requirements for the next 12 months from the date of this Quarterly Report on Form 10-Q. This condition raises substantial doubt about the Company’s ability to continue as a going concern for one year from the date these condensed consolidated financial statements are issued.

The Company's ability to continue as a going concern is dependent on its ability to obtain additional funding to support its business objectives, including achieving its revenue growth rate from sales of ORLYNVAH™ in the United States. The Company has limited experience with and has not yet demonstrated an ability to successfully commercialize a product. Management expects that, in order to obtain additional funding for its operations and commercialization activities, it will need to raise funding through the possible sale of the Company’s equity or debt through additional public or private financings. Although management plans to obtain additional funding to finance its operations, and has successfully raised capital in the past, there is no assurance that we will be successful in obtaining sufficient funding on terms acceptable to us to fund continuing operations, if at all.

If the Company is unable to obtain funding, it could be forced to significantly delay, scale back or discontinue the development and commercialization of its sulopenem program, or otherwise change its strategy, which could adversely affect its business prospects, or the Company may be unable to continue operations. Based on the Company’s operating losses since inception, the expectation of continued operating losses for the foreseeable future, and the need to raise additional capital to finance its future operations, management has concluded there is substantial doubt about the Company’s ability to continue as a going concern within one year from the date these condensed consolidated financial statements are issued.

The accompanying condensed consolidated financial statements do not include any adjustments that might result from the outcome of this uncertainty. Accordingly, the condensed consolidated financial statements have been prepared on a basis that assumes

the Company will continue as a going concern and which contemplates the realization of assets and satisfaction of liabilities and commitments in the ordinary course of business.

Interim Financial Information

The condensed consolidated balance sheet at December 31, 2024 was derived from audited financial statements, but does not include all disclosures required by GAAP. The accompanying unaudited condensed consolidated financial statements as of September 30, 2025 and for the three and nine months ended September 30, 2025 and 2024 have been prepared by the Company pursuant to the rules and regulations of the SEC for interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. These condensed consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements and the notes thereto for the year ended December 31, 2024, included in the Company’s Annual Report on Form 10-K filed with the SEC on February 7, 2025. In the opinion of management, all adjustments, consisting only of normal recurring adjustments necessary for a fair statement of the Company’s financial position as of September 30, 2025, and results of operations for the three and nine months ended September 30, 2025 and 2024, and cash flows for the nine months ended September 30, 2025 and 2024 have been made. The results of operations for the three and nine months ended September 30, 2025 are not necessarily indicative of the results of operations that may be expected for the year ending December 31, 2025.

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, the reported amounts of expenses during the reporting period and the assessment of the Company’s ability to continue as a going concern. Significant estimates and assumptions reflected in these condensed consolidated financial statements include, but are not limited to, the valuation of the RLNs and the accounting for revenue allowances. The Company bases its estimates on historical experience, known trends and other market-specific or other relevant factors that it believes to be reasonable under the circumstances. On an ongoing basis, management evaluates its estimates as there are changes in circumstances, facts and experience. Actual results could differ materially from those estimates.

Specifically, management has estimated variables used to calculate the discounted cash flow analysis (DCF) to value the RLN liability (see Note 4 – Fair Value of Financial Assets and Liabilities) and made estimates in the accounting for revenue allowances (see Note 3 – Revenue).

Cash and Cash Equivalents

The Company’s cash and cash equivalents consist of cash balances and highly liquid investments with maturities of three months or less at the date of purchase. Accounts held at United States financial institutions are insured by the Federal Deposit Insurance Corporation up to $250, while accounts held at Irish financial institutions are insured under the Deposit Guarantee Scheme up to $117 (€100).

Cash accounts with any type of restriction are classified as restricted cash. If restrictions are expected to be lifted in the next twelve months, the restricted cash account is classified as current. Included within restricted cash on the Company’s condensed consolidated balance sheet is $15 and $17 as of September 30, 2025 and December 31, 2024, respectively, relating to the warrants issued on June 5, 2020 pursuant to the securities purchase agreement (June 3, 2020 SPA) from the June 3, 2020 registered direct offering (June 3, 2020 Offering), $4 and $6 as of September 30, 2025 and December 31, 2024, respectively, relating to the warrants issued on July 2, 2020 pursuant to the securities purchase agreement (June 30, 2020 SPA) from the June 30, 2020 registered direct offering (June 30, 2020 Offering) and $10 and $11 as of September 30, 2025 and December 31, 2024, respectively, relating to warrants issued in the underwritten offering in October 2020 (October 2020 Offering). On the closing date of each of the registered direct offerings on June 3, 2020 (June 3, 2020 Offering) and June 30, 2020 (June 30, 2020 Offering) and the underwritten offering in the October 2020 Offering, each investor deposited $0.01 per warrant issued being the nominal value of the underlying ordinary share represented by each warrant. This amount will be held in trust by the Company pending a decision by the relevant investor to exercise the warrant by means of a “cashless exercise” pursuant to the terms of the warrant, in which case the $0.01 will be used to pay up the nominal value of the ordinary share issued pursuant to the warrant. Upon the exercise of the warrants other than by means of a

"cashless exercise", the amount held in trust will be returned to the relevant investor in accordance with the terms of the applicable purchase agreement or prospectus.

Accounts Receivable

Accounts receivable are recorded net of any estimated expected credit losses. The Company's measurement of expected credit losses is based on relevant information about past events, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. No allowance for credit losses was recorded as of September 30, 2025.

Concentration of Credit Risk

Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash and cash equivalents. The Company has most of its cash and cash equivalents at three accredited financial institutions in the United States and Ireland, in amounts that exceed federally insured limits. The Company does not believe that it is subject to unusual credit risk beyond the normal credit risk associated with commercial banking relationships.

The Company is also subject to credit risk related to its trade accounts receivable from product sales. ORLYNVAH™ is distributed primarily through a single retail pharmacy. The Company extends credit to its customer in the normal course of business after evaluating their overall financial condition, and subsequently through payment history and other factors.

Inventory

Inventory is stated at the lower of cost and net realizable value and consists of raw materials, work-in-progress and finished goods (see Note 5 – Inventory for further details). The Company began capitalizing inventory costs following FDA approval of ORLYNVAH™ on October 25, 2024. Inventory is valued on a first-in, first-out basis. The Company periodically reviews inventory for expiry and obsolescence and writes it down accordingly, if necessary. Prior to FDA approval of ORLYNVAH™, the Company expensed all inventory-related costs, including costs incurred for clinical development, to research and development costs in the period in which such costs were incurred.

Revenue Recognition

The Company’s revenue consists of product sales of ORLYNVAH™. See Note 3 – Revenue for more detail on product revenue.

The Company recognizes revenue in accordance with ASC Topic 606, Revenue from Contracts with Customers (ASC 606). The provisions of ASC 606 require the following steps to determine revenue recognition: (i) identification of the promised goods or services in the contract; (ii) determination of whether the promised goods or services are performance obligations including whether they are distinct in the context of the contract; (iii) measurement of the transaction price, including the constraint on variable consideration; (iv) allocation of the transaction price to the performance obligations based on estimated selling prices; and (v) recognition of revenue when (or as) the Company satisfies each performance obligation. At contract inception, the Company assesses the goods or services promised within each contract, determines whether each promised good or service is distinct and identifies those that are performance obligations. The Company recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when (or as) the performance obligation is satisfied.

Cost of Goods Sold

Cost of goods sold consists primarily of direct and indirect costs related to the manufacture of ORLYNVAH™ for commercial sale, including third-party manufacturing costs, raw material and component costs, packaging services, distribution fees and royalties to Pfizer on product sales. Prior to the FDA approval of ORLYNVAH™ in October 2024, costs incurred for the manufacture of ORLYNVAH™ were recorded as research and development expenses and therefore are not included in cost of goods sold. As a result, the cost of goods sold related to ORLYNVAH™ will initially reflect a lower average per unit cost of materials, as previously expensed inventory is utilized and sold to customers.

Net Loss Per Ordinary Share

Basic and diluted net loss per ordinary share is determined by dividing net loss attributable to ordinary shareholders by the weighted-average ordinary shares outstanding during the period in accordance with Accounting Standard Codification (ASC) 260, Earnings per Share. For the periods presented, the following ordinary shares underlying the options, warrants and the Exchangeable Notes have been excluded from the calculation because they would be anti-dilutive.


	Three and Nine Months Ended
	September 30, 2025		September 30, 2024
Options to purchase ordinary shares		940,664		913,988
Warrants		5,906,416		9,663,125
Exchangeable Notes		—		2,541,786
Total		6,847,080		13,118,899

Recent Accounting Pronouncements

From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (FASB) or other standard setting bodies and adopted by the Company as of the specified effective date. Unless otherwise discussed, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on its financial position or results of operations upon adoption.

On October 9, 2023, the FASB issued ASU No. 2023-06, Disclosure Improvements: Codification Amendments in Response to the SEC’s Disclosure Update and Simplification Initiative (ASU 2023-06), which incorporates several disclosures and presentation requirements currently residing in SEC Regulations S-X and S-K. For entities subject to the existing SEC disclosure requirements, including those preparing for sale or issuance of securities, the effective date for each amendment will be the date on which the SEC’s removal of that related disclosure from Regulation S-X or Regulation S-K becomes effective, with early adoption prohibited. For all other entities, the amendments will be effective two years later, with early adoption permitted. ASU 2023-06 is not expected to have a material impact on the consolidated financial statements.

In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures (ASU 2023-09), which enhances the annual income tax disclosures for the effective tax rate reconciliation and income taxes paid. The amendments are effective for public business entities, for annual periods beginning after December 15, 2024 and for annual periods beginning after December 15, 2025 for all other entities. Early adoption is permitted for annual financial statements that have not yet been issued or made available for issuance. The ASU applies on a prospective basis to annual financial statements for periods beginning after the effective date. However, retrospective application in all prior periods presented is permitted. The Company is assessing what impact ASU 2023-09 will have on the consolidated financial statements.

On November 4, 2024, the FASB issued ASU 2024-03, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses (ASU 2024-03), which requires new disclosures to disaggregate prescribed natural expenses underlying any income statement caption. ASU 2024-03 is effective for annual periods in fiscal years beginning after December 15, 2026, and interim periods thereafter. Early adoption is permitted. ASU 2024-03 applies on a prospective basis for periods beginning after the effective date. However, retrospective application to any or all prior periods presented is permitted. The Company is currently assessing the impact ASU 2024-03 will have on the consolidated financial statements and disclosures.

On November 26, 2024, the FASB issued ASU 2024-04, Debt—Debt with Conversion and Other Options (Subtopic 470-20): Induced Conversions of Convertible Debt Instruments (ASU 2024-04), which clarifies the requirements for determining whether certain settlements of convertible debt instruments should be accounted for as an induced conversion. ASU 2024-04 is effective for all entities for annual and interim periods in fiscal years beginning after December 15, 2025. Early adoption is permitted for all entities that have adopted the amendments in ASU 2020-06. ASU 2024-04 is not expected to have a material impact on the consolidated financial statements.

On January 6, 2025, the FASB issued ASU 2025-01, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40): Clarifying the Effective Date (ASU 2025-01), which amends the effective date of ASU 2024-03 to clarify that all public business entities are required to adopt the guidance in annual periods after December 15, 2026, and interim periods in fiscal years beginning after December 15, 2027.

On July 30, 2025, the FASB issued ASU 2025-05, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses for Accounts Receivable and Contract Assets (ASU 2025-05), which provides certain entities with an additional practical expedient and an accounting policy election for estimating expected credit losses on current accounts receivable and current contract assets arising from revenue transactions under ASC 606. This ASU is effective for all entities for annual and interim periods in fiscal years beginning after December 15, 2025. Early adoption is permitted for all entities. ASU 2025-05 is not expected to have a material impact on the consolidated financial statements.

Iterum Therapeutics plc 10-Q