Onconetix, Inc.

Note 1 — Organization and Basis of Presentation

Organization and Nature of Operations

Onconetix, Inc. (formerly known as Blue Water Biotech, Inc. and Blue Water Vaccines Inc.) (the “Company” or “Onconetix”) was formed on October 26, 2018, and is a commercial stage biotechnology company focused on the research, development, and commercialization of innovative solutions for men’s health and oncology.

On December 15, 2023, Onconetix acquired 100% of the issued and outstanding voting equity interests in Proteomedix AG, a Swiss company (“Proteomedix”), and its related diagnostic product Proclarix. As a result of this transaction, Proteomedix became a wholly owned subsidiary of Onconetix. Proteomedix is a healthcare company whose mission is to transform prostate cancer diagnosis. Proteomedix has identified novel biomarker signatures with utility in prostate cancer diagnosis, prognosis and therapy management.

In April 2023, the Company acquired ENTADFI®, a Food and Drug Administration (“FDA”)-approved, once daily pill that combines finasteride and tadalafil for the treatment of benign prostatic hyperplasia.

Historically, the Company’s focus was on the research and development of transformational vaccines to prevent infectious diseases worldwide, until the third quarter of 2023, at which time the Company halted its efforts on vaccine development activities to focus on commercialization activities for ENTADFI and pursue other potential acquisitions. However, in light of (i) the time and resources needed to continue pursuing commercialization of ENTADFI, and (ii) the Company’s cash runway and indebtedness, the Company abandoned commercialization of ENTADFI and no longer holds inventory of ENTADFI. There is currently no plan to resume commercialization of ENTADFI. Based on the circumstances surrounding ENTADFI, the ENTADFI assets were fully impaired at June 30, 2024 (see Notes 4 and 5).

On April 21, 2023, the Company filed an amendment to its Amended and Restated Certificate of Incorporation with the Secretary of State of Delaware to change its corporate name from “Blue Water Vaccines Inc.” to “Blue Water Biotech, Inc.” The name change was effective as of April 21, 2023. On December 15, 2023, the Company filed an amendment to its Amended and Restated Certificate of Incorporation with the Secretary of State of Delaware to change its corporate name from “Blue Water Biotech, Inc.” to “Onconetix, Inc.” In connection with each of the name changes, the Company also amended the Company’s bylaws to reflect the new corporate name.

Reverse Stock Split

On September 24, 2024, the Company effected a reverse stock split of all shares of its issued and outstanding Common Stock at a ratio of one-for-forty (1:40). The Company accounted for the reverse stock split on a retrospective basis pursuant to Accounting Standards Codification (“ASC”) 260,Earnings Per Share. All issued and outstanding common stock, common stock warrants, and share-based awards’ exercise prices and per share data have been adjusted in these consolidated financial statements, on a retrospective basis, to reflect the reverse stock split for all periods presented. The number of authorized shares and par value of the preferred stock and common stock were not adjusted because of the reverse stock split.

Note 1 — Organization and Basis of Presentation(cont.)

On June 13, 2025, the Company effected a reverse stock split of all shares of its issued and outstanding Common Stock at a ratio of one-for-eighty-five (1:85). The Company accounted for the reverse stock split on a retrospective basis pursuant to ASC 260,Earnings Per Share. All issued and outstanding common stock, common stock warrants, and share-based awards’ exercise prices and per share data have been adjusted in these consolidated financial statements, on a retrospective basis, to reflect the reverse stock split for all periods presented. The number of authorized shares and par value of the preferred stock and common stock were not adjusted because of the reverse stock split.

Basis of Presentation and Principles of Consolidation

The Company’s consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and include the accounts of Onconetix and its 100% wholly owned subsidiary, Proteomedix, since the acquisition date of December 15, 2023. All significant intercompany balances and transactions have been eliminated in consolidation.

The non-controlling interest recorded in the accompanying consolidated financial statements as of December 31, 2023 relates to currently outstanding stock-based awards issued by Proteomedix, which were assumed by Onconetix in connection with the acquisition of Proteomedix. During the year ended December 31, 2024, the non-controlling interest converted to equity with the issuance of restricted common stock in exchange for PMX options.

Note 2 — Going Concern and Management’s Plans

The Company’s operating activities to date have been devoted to seeking licenses, engaging in research and development activities, potential asset and business acquisitions, expenditures associated with the previously planned commercial launch of ENTADFI, and the commercialization of Proclarix.

The Company has incurred substantial operating losses since inception and expects to continue to incur significant operating losses for the foreseeable future.

As of December 31, 2025, the Company had cash of approximately $5.2 million, a working capital deficit of approximately $3.1 million and an accumulated deficit of approximately $131.2 million. During the year ended December 31, 2025, the Company used approximately $9.7 million in cash for operating activities. In addition, as of March 11, 2026, the Company’s cash balance was approximately $3.6 million.

The Company successfully closed a Series D financing and a Series E financing in September 2025 and October 2025, respectively. These financings provided the Company with additional cash flow to support near-term operations. While these capital raises may enable the Company to sustain current operations and meet existing obligations, the Company continues to generate recurring net operating losses and has not yet established sustained positive cash flows to support its strategic growth initiatives, which includes the commercialization of Proclarix, and the development and commercialization of the Company’s future product candidates. These factors raise substantial doubt about the Company’s ability to continue as a going concern within one year from the date of the issuance of these consolidated financial statements.

Management’s plans for funding the Company’s operations include generating product revenue from sales of Proclarix, which is still subject to further successful development and commercialization activities within certain jurisdictions. Management also intends to pursue additional equity or debt financing to support operations and strategic initiatives. However, there are currently no committed sources of financing, and there is no assurance that additional funding will be available on favorable terms, if at all. This uncertainty raises significant concern about the Company’s ability to sustain operations and execute its strategic initiatives. If additional capital is not secured, the Company may need to curtail clinical trials, development, and commercialization efforts, and take further measures to reduce expenses to conserve cash.

Because of historical and expected operating losses and net operating cash flow deficits, there is substantial doubt about the Company’s ability to continue as a going concern for one year from the issuance of the consolidated financial statements, which is not alleviated by management’s plans. The consolidated financial statements have been prepared under the going concern basis of accounting. These consolidated financial statements do not include any adjustments that might be necessary from the outcome of this uncertainty.

Note 3 — Summary of Significant Accounting Policies

Use of Estimates

The preparation of the consolidated financial statements in conformity with U.S. 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 consolidated financial statements and the reported amounts of revenue and expenses during the reporting periods. The most significant estimates in the Company’s consolidated financial statements relate to accounting for valuation of inventory, the useful life of the amortizable intangible assets, estimates of future cash flows used to evaluate impairment of intangible assets, accrued research and development expenses, assumptions related to the pension benefit obligation, stock-based compensation, the valuation of preferred stock, valuation of subscription agreement liability, valuation of warrant and derivative liabilities, and the valuation allowance of deferred tax assets. These estimates and assumptions are based on current facts, historical experience and various other factors believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities and the recording of expenses that are not readily apparent from other sources. Actual results may differ materially and adversely from these estimates. To the extent there are material differences between the estimates and actual results, the Company’s future results of operations will be affected.

Segment Information

Operating segments are defined as components of an enterprise about which separate discrete information is available for evaluation by the chief operating decision maker (“CODM”), or decision-making group, in deciding how to allocate resources and in assessing performance. As of December 31, 2025 and 2024, the Company was operating inone segment: commercial. Management’s determination of its operating segments is consistent with the financial information regularly reviewed by the CODM for purposes of evaluating performance, allocating resources, setting incentive compensation targets, and planning and forecasting for future periods.

Concentration of Credit Risk

Financial instruments that potentially subject the Company to concentrations of credit risk consist of cash accounts in financial institutions, which, at times, exceed the Federal Depository Insurance Coverage limit for those maintained in the United States and exceed the Swiss Financial Market Supervisory Authority for those maintained in Switzerland. As of December 31, 2025 and 2024, the Company has not experienced losses on these accounts and management believes the Company is not exposed to significant risks on such accounts.

Foreign Currency Translation

The financial statements of Proteomedix, the Company’s foreign subsidiary, are measured using the local currency, which is the Swiss Franc, as the functional currency. Assets and liabilities of this subsidiary are translated into U.S. dollars at exchange rates as of the consolidated balance sheet date. Equity is translated at historical exchange rates. Revenues and expenses are translated into U.S. dollars at average rates of exchange in effect during the period. The resulting cumulative translation adjustments have been recorded as a separate component of stockholders’ equity, as accumulated other comprehensive income or loss. Foreign currency transaction gains and losses are included in the results of operations. For the years ended December 31, 2025 and 2024, foreign currency translation gain (loss) was approximately $2.8 million and $(5.3) million.

Accounts receivable

The Company performs periodic credit evaluations of its customers’ financial condition and extends credit to virtually all of its customers on an uncollateralized basis. Credit losses to date have been insignificant and within management’s expectations. The Company provides an allowance for credit losses that is based upon a review of outstanding receivables, historical collection information, expected future losses, and existing economic conditions. As of December 31, 2025, there was no allowance for credit losses. As of December 31, 2025, substantially all of the Company’s accounts receivable are due from a single customer.

Inventories

Inventories consist of product acquired in the Proteomedix transaction. Inventories are stated at the lower of cost or net realizable value, with cost determined on a first-in, first-out basis, aside from inventories acquired in an asset acquisition or business combination, which are recorded at fair value. The Company periodically reviews the composition of inventory in order to identify excess, obsolete, slow-moving or otherwise non-saleable items taking into account anticipated future sales compared with quantities on hand, and the remaining shelf life of goods on hand. If non-saleable items are observed and there are no alternative uses for the inventory, the Company records a write-down to net realizable value in the period that the decline in value is first recognized.

Property and Equipment

Property and equipment consists of laboratory equipment, computers, and office furniture and fixtures, all of which are recorded at cost. Depreciation is recorded using the straight-line method over the respective useful lives of the assets ranging fromtwo toten years. Depreciation expense was approximately $15,000 and $22,000 for the years ended December 31, 2025 and 2024 and is included in selling, general and administrative expenses in the accompanying consolidated statements of operations and comprehensive loss.

Acquisitions

The Company evaluates acquisitions to first determine whether a set of assets acquired constitutes a business and should be accounted for as a business combination. If the assets acquired are not a business, the transaction is accounted as an asset acquisition in accordance with Accounting Standards Codification (“ASC”) 805-50,Asset Acquisitions (“ASC 805-50”), which requires the acquiring entity to recognize assets acquired and liabilities assumed based on the cost to the acquiring entity on a relative fair value basis, except for non-qualifying assets including financial assets such as inventory. Further, the cost of the acquisition includes the fair value of consideration transferred and direct transaction costs attributable to the acquisition. Goodwill is not recognized in an asset acquisition and any excess consideration transferred over the fair value of the net assets acquired is allocated to the identifiable assets based on relative fair values. Contingent consideration payments in asset acquisitions are recognized when the contingency is determined to be probable and reasonably estimable. If the assets acquired are a business, the Company accounts for the transaction as a business combination. Business combinations are accounted for by using the acquisition method of accounting. Under the acquisition method, assets acquired, and liabilities assumed are recorded at their respective fair values. The excess of the fair value of consideration transferred over the fair value of the net assets acquired is recorded as goodwill. Acquisition related expenses are expensed as incurred, and are included in selling, general and administrative expense in the consolidated statements of operations and comprehensive loss.

Goodwill and Other Intangible Assets

Goodwill represents the excess of the cost of a business combination over the fair value of the net assets acquired. Goodwill and intangible assets deemed to have indefinite lives are not amortized but are subject to impairment tests on an annual basis, and whenever events or changes in circumstances indicate that the carrying value may not be recoverable. Goodwill is allocated to the reporting unit from which it was created. A reporting unit is an operating segment or sub-segment to which goodwill is assigned when initially recorded. The Company tests indefinite lived intangible assets for impairment, on an annual basis in the fourth quarter, or more frequently if an event occurs or circumstances indicate that the indefinite lived assets may be impaired. The Company may perform a qualitative assessment to determine whether it is more-likely-than-not that the fair value of a reporting unit is less than its carrying amount. If the Company determines this is the case, the Company then performs further quantitative analysis to identify and measure the amount of goodwill impairment loss to be recognized, if any. To perform its quantitative test, the Company compares the fair value of the reporting unit to its carrying value. If the fair value of the reporting unit exceeds the carrying value of its net assets, goodwill is not impaired, and no further testing is required. If the fair value of the reporting unit is less than the carrying value, the Company measures the amount of impairment loss, if any, as the excess of the carrying value over the fair value of the reporting unit. For the years ended December 31, 2025 and 2024, the Company recorded losses on impairment of goodwill of approximately $11.5 million and $32.3 million.

Intangible assets with finite lives are reported at cost, less accumulated amortization, and are amortized over their estimated useful lives, starting when sales for the related product begin. Amortization is calculated using the straight-line method, and recorded within selling, general, and administrative expenses, or cost of revenue, depending on the nature and use of the asset.

During the ordinary course of business, the Company has entered into certain license and asset purchase agreements. Potential milestone payments for development, regulatory, and commercial milestones are recorded when the milestone is probable of achievement. Upon a milestone being achieved, the associated milestone payment is capitalized and amortized over the remaining useful life for approved products or expensed as research and development expense for milestones relating to products whose FDA approval has not yet been obtained.

Impairment of Long-Lived Assets

The Company reviews long-lived assets, including intangible assets with finite useful lives, for impairment whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable (a “triggering event”). Factors that the Company considers in deciding when to perform an impairment review include significant underperformance of the long-lived asset in relation to expectations, significant negative industry or economic trends, and significant changes or planned changes in the use of the assets. If an impairment review is performed to evaluate a long-lived asset for recoverability, the Company compares forecasts of undiscounted cash flows expected to result from the use and eventual disposition of the long-lived asset to its carrying value. An impairment loss would be recognized when estimated undiscounted future cash flows expected to result from the use of an asset are less than its carrying amount. The impairment loss would be based on the excess of the carrying value of the impaired asset over its fair value. During the years ended December 31, 2024, the Company determined that there were certain triggering events that indicated that the carrying amount of the assets recorded in connection with the ENTADFI acquisition may not be fully recoverable. Impairment losses of $3.5 million were recorded during the years ended December 31, 2024 (see Note 4). No additional impairment charges, in relation to the ENTADFI acquisition, were recorded during the year-end December 31, 2025.

During the year ended December 31, 2024, the Company determined there were certain triggering events that indicated the carrying amounts of the assets recorded in connection with the PMX acquisition may not be fully recoverable. Impairment losses of approximately $10.3 million related to the Company’s intangible assets were recorded during the year ended December 31, 2024 resulting in azero balance of the intangible assets as of December 31, 2024 and 2025. There wereno additional impairment charges during the year ended December 31, 2025. See Note 4 for further details.

Fair Value Measurements

Fair value is defined as the price that would be received for sale of an asset or paid for transfer of a liability, in an orderly transaction between market participants at the measurement date. U.S. GAAP establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). These tiers include:

In some circumstances, the inputs used to measure fair value might be categorized within different levels of the fair value hierarchy. In those instances, the fair value measurement is categorized in its entirety in the fair value hierarchy based on the lowest level input that is significant to the fair value measurement. Financial instruments, including cash, inventory, accounts receivable, receivables from related party, accounts payable, accrued liabilities, operating lease liabilities, and notes payable are carried at cost, which management believes approximates fair value due to the short-term nature of these instruments.

The fair value of the contingent warrant liability and the related party subscription agreement liability are valued using significant unobservable measures and other fair value inputs and are therefore classified as Level 3 financial instruments.

The fair value of financial instruments measured on a recurring basis is as follows as of December 31, 2025 and 2024:

These non-financial assets were valued using significant unobservable measures and other fair value inputs and are therefore classified as Level 3 measurements.

None of the Company’s other non-financial assets or liabilities are recorded at fair value on a non-recurring basis as of December 31, 2025 and 2024. There were no transfers between levels during the periods presented.

Deferred Offering Costs

The Company capitalizes certain legal, professional accounting and other third-party fees that are directly associated with in-process equity financing as deferred offering costs until such financings are consummated. After consummation of the equity financing, these costs are recorded in stockholders’ equity as a reduction of proceeds generated as a result of the offering. Should the in-process equity financing be abandoned, the deferred offering costs will be expensed immediately as a charge to expenses in the consolidated statements of operations and comprehensive loss.

Leases

The Company accounts for leases in accordance with ASC 842,Leases. The Company hasone lease agreement for office space, which contains an initial term oftwo years with renewal options. The Company determines if an arrangement is a lease at inception. This determination generally depends on whether the arrangement conveys to the Company the right to control the use of an explicitly or implicitly identified asset for a period of time in exchange for consideration. Control of an underlying asset is conveyed to the Company if the Company obtains the rights to direct the use of and to obtain substantially all of the economic benefits from using the underlying asset.

Operating lease right of use assets and operating lease liabilities are recognized on the lease commencement date. Operating lease right of use assets represent the Company’s right to use an underlying asset for the estimated lease term and operating lease liabilities represent the Company’s present value of its future lease payments. In assessing its lease and determining its lease liability at lease commencement or upon modification, the Company was not able to readily determine the rate implicit for its lessee arrangements and thus has used its incremental borrowing rate on a collateralized basis to determine the present value of the lease payments. The Company’s right of use asset is measured as the balance of the lease liability plus or minus any prepaid or accrued lease payments and any unamortized initial direct costs. The operating lease payments are recognized as lease expense on a straight-line basis over the lease term, and are included in selling, general and administrative expenses in the accompanying consolidated statements of operations and comprehensive loss. Lease payments included in the measurement of the lease liability are comprised of fixed payments. If the Company’s lease agreements include renewal option periods, the Company includes such renewal options in its calculation of the estimated lease term when it determines whether the options are reasonably certain to be exercised. When such renewal options are deemed to be reasonably certain, the estimated lease term determined under ASC 842 will be greater than the non-cancellable term of the contractual arrangement.

Leases with an initial term of 12 months or less are not recorded on the consolidated balance sheet and the Company recognizes lease expense for these leases on a straight-line basis over the lease term. The Company applies this policy to all underlying asset categories.

The Company additionally evaluates leases at their inception to determine if the leases are to be accounted for as an operating lease or a finance lease. Lease expense for operating leases is recognized on a straight-line basis over the lease term. Variable lease payments are recognized in the period in which the obligations for those payments are incurred. Lease expense for finance leases is bifurcated into two components, with the amortization expense component of the right-of-use asset recognized on a straight-line basis and the interest expense component recognized using the effective interest method over the lease term. The Company has no financing leases as of December 31, 2025 or 2024.

Note 3 — Summary of Significant Accounting Policies(cont.)

Defined Benefit Pension Plan

Proteomedix sponsors a defined benefit pension plan (the “Swiss Plan”) covering its eligible Swiss employees. The Swiss Plan is government-mandated and provides retirement benefits based on employees’ years of service and compensation levels. The Company recognizes an asset for the Swiss Plan’s overfunded status or a liability for underfunded status in its consolidated balance sheets. Additionally, the Company measures its plan’s assets and obligations that determine its funded status as of the end of the year and recognizes the changes in the funded status in the year in which the changes occur. Those changes are reported in accumulated other comprehensive loss in the accompanying consolidated statements of convertible preferred stock and stockholders’ equity. The Company uses actuarial valuations to determine its pension and postretirement benefit costs and credits. The amounts calculated depend on a variety of key assumptions, including discount rates and expected return on plan assets. Current market conditions are considered in selecting these assumptions. As of December 31, 2025, the plan was fully settled as a result of the Company terminating its remaining full-time employment arrangements and transitioning to outsourced consulting payroll structures during the year.

Collaborative Agreements

The Company periodically enters into strategic alliance agreements with counterparties to produce products and/or provide services to customers. Alliances created by such agreements are not legal entities, have no employees, no assets and have no true operations. These arrangements create contractual rights and the Company accounts for these alliances as a collaborative arrangement by reporting costs incurred and reimbursements received from transactions within research and development expenses within the consolidated statements of operations and comprehensive loss.

Revenue Recognition

Development Services

Proteomedix provides a range of services to life sciences customers referred to as “Development Services” including testing for biomarker discovery, assay design and development. These Development Services are performed under individual statement of work (“SOW”) arrangements with specific deliverables defined by the customer. Development Services are generally performed on a time and materials basis. During the performance and through completion of the service to the customer in accordance with the SOW, the Company has the right to bill the customer for the agreed upon price and recognizes the Development Services revenue over the period estimated to complete the SOW. The Company generally identifies each SOW as a single performance obligation.

Completion of the service and satisfaction of the performance obligation under a SOW is typically evidenced by access to the data or test made available to the customer or any other form or applicable manner of delivery defined in the SOW. However, for certain SOWs under which work is performed pursuant to the customer’s highly customized specifications, the Company has the enforceable right to bill the customer for work completed, rather than upon completion of the SOW. For those SOWs, the Company recognizes revenue over a period of time during which the work is performed based on the expended efforts (inputs). As the performance obligation under the SOW is satisfied, any amounts earned as revenue and billed to the customer are included in accounts receivable.

Product Sales

The Company derives revenue through sales of its products, which includes Proclarix, its diagnostic product, directly to end users, including laboratories, hospitals, and medical centers, and to distributors. The Company considers customer purchase orders, which in some cases are governed by master sales agreements or standard terms and conditions, to be the contracts with a customer. For each contract, the Company considers the promise to transfer products, each of which is distinct, to be the identified performance obligations. In determining the transaction price, the Company evaluates whether the price is subject to refund or adjustment to determine the net consideration to which it expects to be entitled. The Company fulfills its performance obligation applicable to product sales once the product is transferred to the customer.

Other Revenue

The Company generates other revenue including license revenue through agreements that grant third parties rights to use its intellectual property and proprietary materials. In September 2025, the Company entered into a license agreement with Immunovia AB, under which it granted exclusive rights to certain intellectual property and transferred biological materials related to the PancreaSure™ test. The agreement included two non-refundable payments of $0.3 million. Based on the terms of the agreement and the nature of the license, the Company determined that the performance obligations were satisfied upon the transfer of the licensed rights. Accordingly, the Company recognized $0.6 million as license revenue during the year ended December 31, 2025. The license agreement also states that the Company shall earn a 3% royalty on any sales Immunovia has from products developed using the licensed intellectual property. Further, Immunovia agreed to pay the Company $0.1 million for the delivery of the biological materials. As of December 31, 2025, the Company had not recognized any revenue due to the royalties or due to the biological materials.

As of December 31, 2025 the Company had received payments of $0.3 million due to the license agreement.

As of December 31, 2025 the Company had an outstanding accounts receivable balance of $0.3 million due to the remaining payment from the customer due to the Company by March 31, 2026. As of December 31, 2025, the $0.3 million receivable was reported as accounts receivable, net in the accompanying consolidated balance sheets.

During the years ended December 31, 2025 and 2024, the Company recognized total revenue of approximately $0.8 million and $2.5 million, respectively.

The Company’s revenue was generated from the following geographic regions during the year ended December 31, 2025:

The Company’s revenue was generated from the following geographic regions during the year ended December 31, 2024:

The Company had the following customer concentrations for its revenue during the years ended December 31, 2025 and 2024:

Any revenues earned but not yet billed to the customer as of the date of the consolidated financial statements are recorded as either accounts receivable or contract assets in the accompanying consolidated financial statements, with the difference depending on whether or not the Company’s right to consideration is conditional or unconditional. The Company had approximately $0.3 million and$0 in unbilled accounts receivable as of December 31, 2025 and 2024. Amounts recorded in contract assets are reclassified to accounts receivable in our consolidated financial statements when the right to consideration switches from conditional to unconditional. Accounts receivable was approximately $0.3 million and $0.03 million as of December 31, 2025 and 2024, respectively.

In relation to customer contracts, the Company incurs costs to fulfill a contract but does not incur costs to obtain a contract. These costs to fulfill a contract do not meet the criteria for capitalization and are expensed as incurred.

In circumstances where a SOW includes a variable consideration component, the Company estimates the amount of variable consideration that should be included in the transaction price utilizing either the expected value method or the most likely amount method, depending on which method is expected to better predict the amount of consideration to which the Company will be entitled. The value of variable consideration is included in the transaction price if, and to the extent, it is probable that a significant reversal of the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. These estimates are reassessed each reporting period, as required, and any adjustment required is recorded on a cumulative catch-up basis, which would affect revenue and net loss in the period of adjustment.

Research and Development

The Company expenses the cost of research and development as incurred. Research and development expenses include costs incurred in funding research and development activities, license fees, and other external costs. Advance payments for goods and services that will be used in future research and development activities are expensed when the activity has been performed or when the goods have been received rather than when the payment is made. Upfront and milestone payments due to third parties that perform research and development services on the Company’s behalf will be expensed as services are rendered or when the milestone is achieved. When billing terms under research and development contracts do not coincide with the timing of when the work is performed, the Company is required to make estimates of outstanding obligations as of period end to those third parties. Accrual estimates are based on several factors, including the Company’s knowledge of the progress towards completion of the research and development activities, invoicing to date under the contracts, communication from the research institution or other companies of any actual costs incurred during the period that have not yet been invoiced, and the costs included in the contracts. Significant judgments and estimates may be made in determining the accrued balances at the end of any reporting period. Actual results could differ from the estimates made by the Company. The historical accrual estimates made by the Company have not been materially different from the actual costs (see Note 5).

In accordance with the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 730-10-25-1,Research and Development, costs incurred in obtaining licenses and patent rights are charged to research and development expense if the technology licensed has not reached commercial feasibility and has no alternative future use. The licenses purchased by the Company (see Note 5) require substantial completion of research and development, regulatory and marketing approval efforts to reach commercial feasibility and have no alternative future use. Accordingly, the total purchase price for the licenses acquired is reflected as research and development on the Company’s consolidated statements of operations and comprehensive loss.

Contingencies

Accruals are recorded for loss contingencies when it is probable that a liability has been incurred, and the amount of the related loss can be reasonably estimated. The Company evaluates, on a quarterly basis, developments in legal proceedings and other matters that could cause an increase or decrease in the amount of the liability that has been accrued previously. Considering facts known at the time of the assessment, the Company determines whether potential losses are considered reasonably possible or probable and whether they are estimable. Based upon this assessment, the Company carries out an evaluation of disclosure requirements and considers possible accruals in the consolidated financial statements.

Stock-Based Compensation

The Company expenses stock-based compensation to employees and non-employees over the requisite service period based on the estimated grant-date fair value of the awards. Stock-based awards to employees with graded-vesting schedules are recognized, using the accelerated attribution method, on a straight-line basis over the requisite service period for each separately vesting portion of the award.

The Company estimates the fair value of stock option grants using the Black-Scholes option pricing model and the assumptions used in calculating the fair value of stock-based awards represent management’s best estimates and involve inherent uncertainties and the application of management’s judgment.

Expected Term — The expected term of options represents the period that the Company’s stock-based awards are expected to be outstanding based on the simplified method, which is the half-life from vesting to the end of its contractual term. The simplified method is used as the Company has insufficient historical information to provide a basis for an estimate of the expected term.

Expected Volatility — Volatility is a measure of the amount by which the Company’s share price has historically fluctuated or is expected to fluctuate (i.e., expected volatility) during a period. Due to the lack of an adequate history of a public market for the trading of the Company’s common stock and a lack of adequate company-specific historical and implied volatility data, the Company computes stock price volatility over expected terms based on comparable companies’ historical common stock trading prices. For these analyses, the Company has selected companies with comparable characteristics, including enterprise value, risk profiles, and position within the industry.

Common Stock Fair Value — The fair value of the common stock underlying the Company’s stock options is based on the closing price of the Company’s common stock, as reported by the Nasdaq Capital Market, on the grant date of the award.

Risk-Free Interest Rate — The Company bases the risk-free interest rate on the implied yield available on U.S. Treasury securities with a remaining term commensurate with the estimated expected term.

Expected Dividend — The Company has never declared or paid any cash dividends on its shares of common stock and does not plan to pay cash dividends in the foreseeable future, and, therefore, uses an expected dividend yield of zero in its valuation models.

The Company recognizes forfeitures of equity awards as they occur.

Income Taxes

Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards.

Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the jurisdictions and years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rate is recognized in operations in the period that includes the enactment date. Deferred tax assets are reduced to estimated amounts expected to be realized by the use of a valuation allowance.

Note 3 — Summary of Significant Accounting Policies(cont.)

Comprehensive Loss

The Company is required to report all components of comprehensive loss, including net loss, in the accompanying consolidated financial statements in the period in which they are recognized. Comprehensive loss is defined as the change in equity during a period from transactions and other events and circumstances from non-owner sources. The Company’s comprehensive losses for the years ended December 31, 2025 and 2024 are comprised of net loss, the effect of currency translation adjustments, and the change in pension benefit obligation.

Financial instruments

The Company determines the accounting classification of financial instruments that are issued, including its warrants and a subscription agreement, as either liability or equity, by first assessing whether the financial instruments are freestanding financial instruments, and if they meet liability classification in accordance with ASC 480,Distinguishing Liabilities from Equity, (“ASC 480”), and then in accordance with ASC 815-40,Derivatives and Hedging – Contracts in Entity’s Own Equity(“ASC 815-40”). Under ASC 480-10, financial instruments are considered liability-classified if the instruments are mandatorily redeemable, obligate the issuer to settle the instruments or the underlying shares by paying cash or other assets, or must or may require settlement by issuing a variable number of shares.

If the instruments do not meet liability classification under ASC 480, the Company assesses the requirements under ASC 815-40, which states that contracts that require or may require the issuer to settle the contract for cash are liabilities recorded at fair value, irrespective of the likelihood of the transaction occurring that triggers the net cash settlement feature. If the financial instruments do not require liability classification under ASC 815-40, in order to conclude equity classification, the Company assesses whether the instruments are indexed to the Company’s common stock and whether the instruments are classified as equity under ASC 815-40 or other applicable GAAP. After all relevant assessments are made, the Company concludes whether the instruments are classified as liability or equity. Liability-classified instruments are required to be accounted for at fair value both on the date of issuance and on subsequent accounting period ending dates, with all changes in fair value after the issuance date recorded as a component of other income (expense), net in the consolidated statements of operations and comprehensive loss. Equity-classified instruments are accounted for at fair value on the issuance date with no changes in fair value recognized after the issuance date.

Preferred Stock

The Company applies the guidance enumerated in ASC 480, when determining the classification and measurement of preferred stock. Preferred stock subject to mandatory redemption, if any, is classified as a liability and is measured at fair value. The Company classifies conditionally redeemable preferred stock, which includes preferred stock that features redemption rights that are either within the control of the holder or subject to redemption upon the occurrence of uncertain events not solely within the Company’s control, as temporary equity. At all other times, the Company classifies its preferred stock in stockholders’ equity.

Treasury Stock

The Company records treasury stock activities under the cost method whereby the cost of the acquired stock is recorded as treasury stock.

Recently Adopted Accounting Standards

From time to time, new accounting pronouncements are issued by the FASB or other standard setting bodies and are adopted by the Company as of the specified effective date.

In December 2023, the FASB issued ASU No. 2023-09, Income Taxes (Topic 740*): Improvements to Income Tax Disclosures*. This ASU requires disclosure of specific categories in the rate reconciliation and additional information for reconciling items that meet a quantitative threshold. The amendment also includes other changes to improve the effectiveness of income tax disclosures, including further disaggregation of income taxes paid for individually significant jurisdictions. This ASU is effective for annual periods beginning after December 15, 2024. Adoption of this ASU should be applied on a prospective basis. Early adoption is permitted. The Company has adopted the improvements to income tax disclosure requirements with no significant impact on its disclosures.

Recent Accounting PronouncementsNot Yet Adopted**

In November 2024, the FASB issued ASU No. 2024-03,Disaggregation of Income Statement Expenses. This guidance will require additional disclosures and disaggregation of certain costs and expenses presented on the face of the income statement. The amendments are effective for annual reporting periods beginning after December 15, 2026 and interim reporting period beginning after December 15, 2027 with early adoption permitted. The Company is currently evaluating the impact of this new guidance to our consolidated financial statements.

The Company’s management does not believe that any other recently issued, but not yet effective, accounting standards, if currently adopted, would have a material effect on the accompanying consolidated financial statements.

Note 4 — Balance Sheet Details

Inventories

Inventories, which primarily relate to Proclarix product as of December 31, 2025 and 2024, consisted of the following:

The Company recorded an impairment on the ENTADFI inventory in the amount of approximately $0.4 million during the year ended December 31, 2024, which fully reserved all remaining inventory related to ENTADFI. There wereno additional impairments recorded on inventory during the year ended December 31, 2025. Additionally, during the year ended December 31, 2025, the Company fully abandoned ENTADFI and disposed of the remaining inventory.

Investor Receivable

The Company recorded a receivable of approximately $50,000 pertaining to professional service fees paid by the Company on behalf of an investor in connection with the Series E financing. The receivable is non-interest bearing and is presented as investor receivable within the accompanying consolidated balance sheet.

Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consisted of the following as of December 31, 2025 and 2024:

Intangible Assets

Intangible assets acquired in connection with the ENTADFI and Proteomedix acquisitions were comprised of customer relationships, product rights for developed technology, and a trade name. These intangibles were fully impaired during the year ended December 31, 2024, resulting in azero balance as of December 31, 2025 and 2024.

Changes in intangible assets recorded during the year ended December 31, 2024 consisted of the following:

The finite lived intangible assets held by the Company, which includes trade name, customer relationships and product rights for developed technology, were being amortized over their estimated useful lives, which is 15 years. Amortization expense related to intangible assets was approximately $0.7 million for the year ended December 31, 2024, of which approximately $457,000 and $252,000 was recorded as cost of revenue and selling, general, and administrative expenses, respectively, in the accompanying consolidated statements of operations and comprehensive loss. The Company did not record any additions, impairments, or other changes in intangible assets during the year ended December 31, 2025.

ENTADFI Intangible Asset Impairment

In 2024, the Company recorded impairment charges related to its ENTADFI asset group after determining that the carrying amount was not recoverable. As of June 30, 2024, the ENTADFI asset group was fully impaired and had no remaining carrying value.

Proteomedix Intangible Assets Impairment

During the year ended December 31, 2024, the Company recorded a full impairment charge related to the intangible assets acquired in connection with the PMX acquisition. As a result, the carrying value of these intangible assets was reduced tozero as of December 31, 2024.

Goodwill

Goodwill consisted of the following as of December 31, 2025 and 2024:

Impairments for years ended December 31, 2025 and 2024

During the years ended December 31, 2025 and 2024, the Company recognized goodwill impairment losses of approximately $11.5 million and $32.3 million, respectively.

During the year ended December 31, 2025, the Company performed quantitative goodwill impairment analyses during each quarter as a result of sustained declines in the Company’s stock price and market capitalization. The fair value of the reporting unit during the year ended December 31, 2025 was estimated primarily using a market capitalization approach, which was derived from the Company’s fully-diluted market capitalization calculated using an indicative share price based on the December 31, 2025 closing price.

During the year ended December 31, 2024, the Company identified multiple indicators of goodwill impairment primarily related to declines in its stock price and market capitalization, changes in market conditions, and the anticipated timing of projected sales. As a result, the Company performed quantitative goodwill impairment assessments throughout 2024, which resulted in cumulative impairment charges of approximately $32.3 million. These charges included impairments recognized in the first and second quarters of 2024 and an additional impairment recognized in the fourth quarter of 2024 following a measurement-period adjustment related to the Proteomedix acquisition.

During 2024, the Company also reassessed its reporting unit structure and determined that, effective April 30, 2024, it operated as a single reporting unit, which was considered in its impairment analyses. Fair value was estimated using a combination of the income approach, the market approach, and the Company’s market capitalization, with valuation methodologies evolving during the year based on changes in facts and circumstances. In the first and second quarters of 2024, the Company estimated fair value using a combination of the income approach and market approach (market multiples), with results reconciled to the Company’s market capitalization. In the third quarter of 2024, the Company shifted to an income approach, still reconciled to market capitalization, because previously selected guideline transactions and comparable-company inputs were no longer considered representative of the Company’s circumstances. In the fourth quarter of 2024, the Company estimated fair value based on the Company’s market capitalization.

Under the income approach, the Company estimated the fair value of the reporting unit based on the present value of estimated future cash flows, which the Company considers to be a Level 3 unobservable input in the fair value hierarchy. The Company prepared cash flow projections based on management’s estimates of future revenue and operating costs, taking into consideration the historical performance and the current macroeconomic, industry, and market conditions. The Company based the discount rate on the weighted-average cost of capital considering Company-specific characteristics and changes in the reporting unit’s projected cash flows. Under the market approach, the Company estimated the fair value of the reporting unit based on revenue market multiples derived from comparable companies with similar characteristics as the reporting unit, as well as an estimated control premium.

Measurement period adjustment for year ended December 31, 2024

During 2024, the Company identified a measurement period adjustment relating from the Proteomedix acquisition resulting in an increase to the acquired goodwill of approximately $8.4 million.

Accrued Expenses

Accrued expenses consisted of the following as of December 31, 2025 and 2024:

Note 5 — Significant Agreements

Services Agreement

On July 21, 2023, the Company, entered into a Licensing and Services Master Agreement (“Master Services Agreement”) and a related statement of work with a vendor, pursuant to which the vendor was to provide to the Company commercialization services for the Company’s products, including recruiting, managing, supervising and evaluating sales personnel and providing sales-related services for such products, for fees totaling up to $29.1 million over the term of the statement of work. The statement of work had a term through September 6, 2026, unless earlier terminated in accordance with the Master Services Agreement and the statement of work. On July 29, 2023, a second statement of work was entered into with the same vendor for certain subscription services providing prescription market data access to the Company. The fees under the second statement of work totaled approximately $0.8 million, and the term was through July 14, 2025. On October 12, 2023, the Company terminated the Master Services Agreement and the statements of work. During 2023, the Company recognized a termination fee of approximately $1.4 million included in selling, general and administrative expense. Subsequently during 2024, the Company agreed with the vendor to pay a reduced termination fee of approximately $0.9 million and recorded net credits of $0.5 million for the difference in the termination fee related to this contract during the year ended December 31, 2024, which was included in selling, general and administrative expense for the year then ended. During the year ended December 31, 2025, the Company settled the remaining balance of the termination fee and recognized a $0.9 million gain on forgiveness of accounts payable in the accompanying consolidated statement of operations and comprehensive loss.

Note 5 — Significant Agreements(cont.)

Laboratory Corporation of America

On March 23, 2023, Proteomedix entered into a license agreement with LabCorp, pursuant to which LabCorp has the exclusive right to develop and commercialize Proclarix, and other products developed by LabCorp using Proteomedix’s intellectual property covered by the license, in the United States (“Licensed Products”). In consideration for granting LabCorp an exclusive license, Proteomedix received an initial license fee of in the mid-six figures upon signing of the contract. Additionally, Proteomedix is entitled to royalty payments of between 5% and 10% on the net sales recognized by LabCorp of any Licensed Products plus milestone payments as follows:

The total milestone payments available under the terms of this contract are $2.5 million. An additional $0.5 million was paid to Proteomedix as an initial license fee in 2023.

LabCorp is wholly responsible for the cost, if any, of research, development and commercialization of Licensed Products in the United States but has the right to offset a portion of those costs against future royalty and milestone payments. Additionally, LabCorp may deduct royalties or other payments made to third parties related to the manufacture or sale of Licensed Products up to a maximum amount of any royalty payments due to Proteomedix. There was no such activity under the agreement for the year ended December 31, 2025.

The license agreement and related royalty payment provisions expire during 2038, which approximates the expiration of the last patent covered by the license agreement. LabCorp has the right to terminate the license agreement for any reason by providing 90 days written notice to Proteomedix. Either party may terminate the license agreement due to a material reach of the terms of the license agreement with 40 days’ notice, provided such breach is not cure within the foregoing 30-day period. Finally, Proteomedix may terminate the license agreement with 60 days’ notice in the event LabCorp fails to make any undisputed payment due, provided that LabCorp does not remit the payment within the foregoing 60-day period.

As of December 31, 2025, the sale of Licensed Products by LabCorp under the license agreement has not commenced. The Company has sold product to LabCorp for their use in internal trials of the test.

On December 6, 2025, the Company entered into an amendment with LabCorp that adds in a clause for LabCorp to complete a research study on behalf of the Company. This amendment does not affect the licensing agreement or any conclusions therein. The Company engaged LabCorp to complete a study and will pay LabCorp for these services separately. Under the amendment, the Company is obligated to reimburse LabCorp for study-related services based on subject enrollment milestones, with total payments capped at $0.3 million. Management currently estimates total study costs to be in the mid-five-figure range; however, actual costs may vary depending on enrollment levels and study execution.

Immunovia AB

On September 17, 2025, Proteomedix entered into a license agreement with Immunovia AB, pursuant to which Immunovia obtained exclusive rights to certain intellectual property and proprietary biological materials related to the PancreaSure™ test. In exchange for these rights, Immunovia paid Proteomedix a non-refundable upfront license fee of $0.3 million. Based on the terms of the agreement and the nature of the license, the Company determined that the performance obligations were satisfied upon the transfer of the licensed rights. Accordingly, the Company recognized the $0.6 million as license revenue during the year ended December 31, 2025. Additionally, the agreement provides for a second payment of $0.3 million due by March 31, 2026.

Under the terms of the agreement, Immunovia is responsible for the development, manufacturing, and commercialization of the PancreaSure™ test in the United States. Proteomedix is also entitled to receive royalty payments based on net sales of the licensed product. The royalty structure includes a tiered percentage of net sales of 3%, depending on sales volume thresholds. Immunovia may deduct certain third-party costs related to the manufacture or sale of the licensed product from the royalty payments, subject to specified limits.

Note 5 — Significant Agreements(cont.)

The license agreement includes customary termination provisions, including termination for convenience with advance notice, and termination for material breach or non-payment. The agreement does not require Proteomedix to provide ongoing services or support following the initial transfer of rights and materials.

As of December 31, 2025, the Company received the initial nonrefundable license payment of $0.3 million, and the sale of the Licensed Products by Immunovia under the license agreement has not commenced.

As of December 31, 2025 the Company had an outstanding accounts receivable balance of $0.3 million due to the payment from the customer due to the Company by March 31, 2026. As of December 31, 2025, the Company’s accounts receivable balances were reported as accounts receivable, net in the accompanying consolidated balance sheets.

Consulting Agreement

On June 17, 2025, the Company entered into a consulting agreement with a firm affiliated with Thomas Meier, PhD, (see Note 11) pursuant to which the consulting firm provides strategic and transactional advisory services, including services related to the Immunovia license agreement. Under the terms of the agreement, the consulting firm is eligible to earn success fees based on transaction proceeds and reimbursement of related expenses. During the year ended December 31, 2025, the Company recognized approximately $0.03 million of expense related to success fees under this agreement, and approximately $0.02 million was included in accounts payable as of December 31, 2025.

Note 6 — Notes Payable

Veru Notes Payable

As December 31, 2024, the Company had two non-interest-bearing notes payable outstanding with principal amounts of $5.0 million and initial maturity dates of April 19, 2024 (“April Veru Note”), and September 30, 2024 (“September Veru Note” and together with the April Veru Note, the “Veru Notes”), respectively. In accordance with the Veru Notes, no principal payments are due until maturity; however, the Company may voluntarily prepay the Veru Notes with no penalty. Additionally, in an Event of Default, as defined in the Veru Notes, the unpaid principal amount of the Veru Notes will accrue interest at a rate of 10.0% per annum.

The Company imputed interest on the Veru Notes using an average discount rate of 8.2% and recorded a debt discount of approximately $1.1 million at the issuance date. The debt discount is reflected as a reduction in the carrying amount of the Notes and amortized to interest expense through the respective maturity dates, using the effective interest method.

On April 24, 2024, the Company entered into a forbearance agreement with Veru (the “Original Forbearance Agreement”) due to the Company’s failure to repay the principal balance on the $5.0 million note payable that had a maturity date of April 19, 2024 (the “April Veru Note”). Pursuant to the Original Forbearance Agreement, Veru will forbear from exercising its rights and remedies under the April Veru Note as a result of this default, until March 31, 2025 (the “April 2024 Forbearance Period”).

Interest will accrue on any unpaid principal balance of the April Veru Note at a rate of 10% per annum, commencing on April 20, 2024 through the date that the outstanding principal balance under the April Veru Note is paid in full. Any such accrued interest will become immediately due and payable upon the earlier of (i)certain events of default under the April Veru Note or the $5.0 million note payable that matures on September 30, 2024 (the “September Veru Note”), (ii) a payment default under the September Veru Note and (iii) the final payment of any principal amount payable under the September Veru Note. No interest was to accrue under the September Veru Note during the April 2024 Forbearance Period unless an Event of Default (as defined in the Original Forbearance Agreement) occurs, in which case interest will accrue from and after the date on which such default occurs.

In consideration for Veru’s entrance into the Original Forbearance Agreement, the Company agreed to pay Veru:

The Company also agreed to a general release of claims against Veru and its representatives arising out of or relating to any act or omission thereof prior to April 24, 2024.

The Company determined that the Original Forbearance Agreement should be accounted for as a modification of the April Veru Note and the September Veru Note in accordance with ASC 470-50,Debt - Modifications and Extinguishments(“ASC 470”), as the change in cash flows expected under the April Veru Note and the September Veru Note was not substantial. A new effective interest rate was established based on the carrying value of the original Notes and the revised cash flows and no gain or loss was recorded.

On September 19, 2024, the Company entered into an Amended and Restated Forbearance Agreement with Veru (the “Amended and Restated Forbearance Agreement” or “A&R Forbearance Agreement”), which amends and restates the Original Forbearance Agreement in its entirety. Pursuant to the A&R Forbearance Agreement, Veru will forbear from exercising its rights under both the April Veru Note and the September Veru Note, subject to the terms and conditions set forth below.

The A&R Forbearance Agreement extends the due date for the April 2024 and September 2024 Veru Notes until the earlier to occur of (i) June 30, 2025 or (ii) the occurrence of any Event of Default. The Amended and Restated Forbearance Agreement also effected certain modifications to the payment terms in the Original Forbearance Agreement and amended certain terms of the September Veru Note as summarized below.

Pursuant to the A&R Forbearance Agreement, the Company agreed to make the following required payments (the “Required Payments”) during the April 2024 Forbearance Period, first to accrued and unpaid interest under the April Veru Note and then any remainder to the outstanding principal amount of the April Veru Note:

The Company and Veru also agreed to the following amendments to the September Veru Note in the A&R Forbearance Agreement:

The Company determined the A&R Forbearance Agreement should be accounted for as a modification of both the April and September Veru Notes in accordance with ASC 470-50,Debt - Modifications and Extinguishments (“ASC 470”), as the change in cash flows expected under the April Veru Note and the September Veru Note was not substantial. A new effective interest rate was established based on the carrying value of the original Notes and the revised cash flows and no gain or loss was recorded.

On November 26, 2024, the Company entered into another Amended and Restated Forbearance Agreement with Veru (the “November Amended and Restated Forbearance Agreement” or “November A&R Forbearance Agreement”), which amends and restates certain terms of the Amended and Restated Forbearance Agreement. Pursuant to the November A&R Forbearance Agreement, Veru agreed to waive the due date for payment of applicable Cash Receipt Payments (as such term is defined in the A&R Forbearance Agreement) generated in October 2024 until the Company receives funds of at least $97,000 pursuant to its equity line of credit facility with Keystone Capital Partners LLC. In exchange, the Company agreed to increase its payments to be made to Veru out of future financing and strategic transactions through June 30, 2025, from 20% to 25% of net proceeds generated from such transactions. All other terms of the A&R Forbearance Agreement with Veru remain the same. Management has evaluated and concluded that there is no accounting impact from the A&R Forbearance Agreement with Veru.

On March 31, 2025, Veru and the Company entered into a waiver agreement, pursuant to which Veru agreed to waive and extend the date for payment of the April Veru Note to April 14, 2025.

On April 23, 2025, Veru and the Company entered into a limited waiver agreement, pursuant to which Veru agreed to waive and extend the date for payment of the April Veru Note to June 30, 2025.

On June 30, 2025, Veru and the Company entered into a limited waiver agreement, pursuant to which Veru agreed to waive and extend the date for payment of the Veru Notes to July 31, 2025.

On July 31, 2025, Veru and the Company entered into a waiver agreement, pursuant to which Veru agreed to waive and extend the date for payment of the Veru Notes to August 14, 2025.

On August 7, 2025, Veru and the Company agreed to amend and restate the September Veru Note to increase the principal amount owed to Veru by $100,000 to an aggregate principal amount of $5.1 million and extend the maturity date to August 14, 2025. All other terms of the September Veru Note remained the same.

On August 14, 2025, Veru and the Company entered into a waiver agreement, pursuant to which Veru agreed to waive and extend the date for payment of the April Veru Note and the September Veru Note to August 31, 2025.

On August 28, 2025, Veru and the Company agreed to amend and restate the September Veru Note. Pursuant to the September Veru Note, the principal amount owed to Veru was increased by $100,000 to an aggregate principal amount of $5.2 million, and the maturity date was amended to September 19, 2025. All other terms of the September Veru Note remained the same.

On August 28, 2025, Veru and the Company also entered into a waiver agreement, pursuant to which Veru agreed to waive and extend the date for payment of the September Veru Note to September 19, 2025.

As of September 22, 2025, approximately $8.8 million was payable to Veru under the Veru Notes and related amendments. On September 22, 2025, the Company and Veru entered into a Settlement Agreement and Release (the “Veru Settlement Agreement”), pursuant to which Veru agreed to accept a cash payment of approximately $6.3 million (including interest accrued through receipt of the Settlement Amounts (as defined herein)),3,125 shares of Series D Preferred Stock (as defined below) and 846,975 Series D Warrants (as defined below) from a Series D PIPE Financing (as defined below) entered between the Company and certain institutional investors on September 22, 2025 (such cash payment, shares of Series D Preferred Stock and Series D Warrants, collectively, the “Settlement Amounts”) in full satisfaction of all amounts due under the Veru Notes, as amended by all preceding amendments, forbearance agreements, and waivers, and Veru agreed that such acceptance constituted complete discharge of all obligations thereunder. The Settlement Agreement contains customary release provisions that upon timely delivery of the Settlement Amounts, Veru shall release all claims or actions against the Company. The transaction was accounted for as a debt extinguishment in accordance with ASC 405-20 and ASC 470-50. The Company derecognized the carrying amount of the Veru Notes and recognized a gain or loss on extinguishment equal to the difference between the reacquisition price—measured at the fair value of the cash and equity instruments transferred—and the net carrying value of the debt. The Company recognized a loss on extinguishment related to this transaction of $3,516,811 recorded within loss on extinguishment of notes payable in the accompanying consolidated statement of operations and comprehensive loss for the year ended December 31, 2025.

On September 24, 2025, Veru confirmed receipt of all Settlement Amounts in satisfaction of all outstanding amounts, and all Veru Notes and related amendments were deemed cancelled and terminated, respectively, and of no further force or effect.

During the year ended December 31, 2025 and 2024, the Company recorded approximately $0.8 million and $1.4 million of associated interest expense, respectively, which includes accrued interest and amortization of the debt discount. The unamortized debt discount as of December 31, 2025 and 2024 was$0 and $5,000. As of December 31, 2025 and 2024, the Company has recorded accrued interest of approximately$0 and $0.1 million on the Notes, which is included in accrued expenses in the accompanying consolidated balance sheets.

There are no future minimum principal payments on the Veru Notes as of December 31, 2025 as the Veru Notes are fully paid off and extinguished in accordance with the Veru Settlement Agreement.

Related Party Debenture

On January 23, 2024, the Company issued a non-convertible debenture (the “Debenture”) to the PMX Investor, a related party, in the principal sum of $5.0 million, in connection with the Subscription Agreement discussed in Note 7. The Debenture has an interest rate of 4.0% per annum, and the principal and accrued interest was originally payable in full upon the earlier of (i) the closing under the Subscription Agreement and (ii) June 30, 2024. Additionally, the $5.0 million subscription amount under the Subscription Agreement shall be increased by the amount of interest payable under the Debenture.

On April 24, 2024, the maturity date of the related party debenture was extended to October 31, 2024, through the execution of an extension agreement (the “Extension Agreement”) between the Company and the PMX investor. No other terms of the Debenture were modified in connection with the Extension Agreement.

The Company considered the guidance of ASC 470-60,Troubled Debt Restructuring by Debtors, and concluded that the Extension Agreement should be accounted for as a troubled debt restructuring as the Company is experiencing financial difficulty and since the effective borrowing rate under the Extension Agreement is less than the effective borrowing rate under the original agreement, which indicates that a concession is deemed to have been granted. This did not result in a gain on restructuring as the future undiscounted cash outflows required under the Extension Agreement exceed the carrying value of the Debenture immediately prior to the extension. A new effective rate was established based on the carrying value of the original Debenture and the revised cash flows.

In connection with the issuance of the Debenture, the Company incurred approximately $0.4 million in financing fees, which was recorded as a debt discount, and reflected as a reduction in the carrying amount of the Debenture. The debt discount is being amortized to interest expense through the maturity date. The Company did not incur any financing fees in connection with the Extension Agreement.

On September 24, 2024, the Company converted all unpaid principal and accrued interest due under the Debenture into 5,882 units, attributable to principal, and 158 units, attributable to accrued interest, upon the closing of the Subscription Agreement. Each unit consisted of 1 share of common stock and 0.30 pre-funded warrants at an exercise price of $3.40 per share. As a result of the transaction,6,040 shares of common stock were issued, and 1,812 pre-funded warrants were issued. As of December 31, 2024, there is no outstanding balance or accrued interest remaining on the Debenture. The remaining unamortized debt discount was immediately expensed upon settlement.

The Company recorded approximately $0.5 million of interest expense on the Debenture during the year ended December 31, 2024 which includes accrued interest and amortization of the debt discount. There wasno such interest expense during the year ended December 31, 2025.

Insurance Financing

During the years ended December 31, 2025 and 2024, the Company obtained financing for certain Director & Officer liability insurance policy premiums. The agreement assigns the lender a first priority lien on and security interest in the financed policies and any additional premium required in the financed policies.

During 2024, the total premiums, taxes and fees financed are approximately $0.7 million, with an annual interest rate of 7.79%. In consideration of the premium payment by the lender to the insurance companies or the agent or broker, the Company unconditionally promised to pay the lender the amount financed plus interest and other charges permitted under the agreement. As of December 31, 2024, the company had paid off the insurance financing note payable. The Company paid the insurance financing through monthly installment payments of approximately $78,000, the last payment for the note was paid on November 17, 2024.

During 2025, the total premiums, taxes and fees financed are approximately $0.5 million, with an annual interest rate of 7.25%. In consideration of the premium payment by the lender to the insurance companies or the agent or broker, the Company unconditionally promised to pay the lender the amount financed plus interest and other charges permitted under the agreement. The Company paid the insurance financing through monthly installment payments of approximately $52,768, with the last payment for the note occurring on November 17, 2025. As of December 31, 2025, the insurance financing is fully paid off and the insurance policy remains in effect until February 17, 2026.

Keystone Notes Payable

During the year ended December 31, 2025, the Company issued six subordinated promissory notes to Keystone Capital Partners, LLC, each with an original issue discount and payable upon the earlier of (i) receipt of sufficient proceeds from the Company’s Equity Line of Credit (“ELOC”) with the Investor or (ii) a specified maturity date. All notes are subordinated to the Company’s existing debt obligations to Veru, do not initially bear interest, and are subject to a late charge of 15% per annum on any unpaid amounts past due.

On September 22, 2025, Keystone Capital Partners, LLC and the Company agreed to exchange the principal owed under the May Keystone Note, the June Keystone Note, the August 6 Keystone Note and the August 28 Keystone Notes for Series D Preferred Stock and Warrants in connection with the Series D PIPE Financing. The February Keystone Note was fully paid off as of October 10, 2025. The transaction was accounted for as a debt extinguishment in accordance with ASC 405-20 and ASC 470-50. The Company derecognized the carrying amount of the Keystone Notes and recognized a gain or loss on extinguishment equal to the difference between the reacquisition price, measured at the fair value of the cash and equity instruments transferred, and the net carrying value of the debt. The Company recognized a loss on extinguishment related to this transaction of $1,867,908 recorded within loss on extinguishment of notes payable in the accompanying consolidated statement of operations and comprehensive loss for the year ended December 31, 2025.

During the year ended December 31, 2025, the Company recorded approximately $0.1 million of amortization of the debt discount.

Note 7 — Subscription Agreement

On December 18, 2023, the Company entered into a subscription agreement (the “Subscription Agreement”) with the PMX Investor, who became a stockholder of Onconetix at the closing of the PMX Transaction (see Note 11), for the sale of 5,882 units, each comprised of 1 share of common stock and 0.30 pre-funded warrants (the “Units”) at $850 per Unit. The Subscription Agreement includes a make-whole provision (the “Make-Whole Provision”) which requires the issuance of additional shares of common stock in the event that the 270-day volume weighted average price after the closing of the Subscription Agreement, is below $850, and the PMX Investor still holds the common shares acquired upon closing of the Subscription Agreement 270 days after such closing. The Subscription Agreement would only close upon obtaining stockholder approval for certain transactions involving the Company’s Series B Preferred Stock. The Subscription Agreement was amended on January 23, 2024 to include a provision for interest on the $5 million debenture, accruing at a rate of 4%, to be included in the calculation of the units to be issued upon the conversion. Stockholder approval was obtained on September 5, 2024, and as a result, the conversion and the issuance of 5,882 units, attributable to the Subscription Agreement, and 158 units, attributable to additional accrued interest under the debenture to the PMX Investor took place on September 24, 2024.

On June 24, 2025, the 270-day volume weighted average price after the closing of the Subscription Agreement was below $850. In accordance with the Make-Whole Provision under the Subscription Agreement, the Company issued 241,514 shares of common stock (the “Make-Whole Shares”) to Altos Venture AG, following the determination that the 270-day volume weighted average price (“Issuer VWAP”) was below the $850 threshold. The Company recorded common stock of $2 and additional paid in capital of $995,036 related to the issuance of the 241,514 shares in the accompanying consolidated balance sheet as of December 31, 2025.

The Subscription Agreement was accounted for as a liability in accordance with ASC 480,Distinguishing Liabilities from Equity, (“ASC 480”), as the make-whole provision could result in a variable number of shares being issued upon settlement. The related party subscription agreement liability was measured at fair value at the commitment date and remeasured at each subsequent reporting period, with changes in fair value recorded as a component of other income (expense), net in the consolidated statements of operations and comprehensive loss.

During the year ended December 31, 2025, the subscription agreement liability - related party expired and was settled resulting in the recognition of $2 in common stock and $995,036 in additional paid in capital as of December 31, 2025.

The following table summarizes the activity for the related party subscription agreement liability, using unobservable Level 3 inputs, for the years ended December 31, 2025 and 2024:

As of December 31, 2025 and 2024, the fair value of the related party subscription agreement liability was approximately $0 and $4,123,000, respectively. For the years ended December 31, 2025 and 2024, the Company recognized a (gain) loss in change in fair value of the related party subscription agreement liability of approximately $(3,127,962) and $3,259,000, respectively.

The fair value was determined using a Monte-Carlo option pricing model, and as of December 31, 2024, the Company utilized 100% probability that the Subscription Agreement will close. The significant assumptions used in the Monte-Carlo model, which utilizes Level 3 inputs (see Note 3), are as follows as of December 31, 2024:

Note 8 — Warrant and derivative liabilities

Contingent warrant liabilities

The following table summarizes the activity for the contingent warrant liabilities, using unobservable Level 3 inputs, for the years ended December 31, 2025 and 2024:

Series D derivative liabilities and warrant liabilities

On September 22, 2025, the Company completed a private placement transaction with institutional investors, resulting in the issuance of Series D convertible preferred stock and accompanying warrants to purchase shares of common stock. In connection with this transaction, the Company recorded warrant liabilities related to the Series D Warrants and derivative liabilities associated with certain embedded features in the Series D Preferred Stock. These instruments were classified as liabilities and measured at fair value in accordance with ASC 815 due to their settlement provisions and other contractual terms. Refer to Note 9 for further detail on the private placement transaction.

The Company measured its bifurcated embedded derivative liabilities and warrant liabilities as of December 31, 2025 and September 22, 2025, at fair value on a recurring basis using level 3 inputs. These financial instruments are measured using management’s best estimate of fair value, where the inputs into the determination of fair value require significant management judgment to estimation. The derivative liabilities and warrant liabilities were both measured using Monte Carlo valuation models. Valuations based on unobservable inputs are highly subjective and require significant judgments. Changes in such judgments could have a material impact on fair value estimates.

As of December 11, 2025 the Company had entered a letter of intent with Realbotix (“LOI”), which contemplates a change of control transaction. A closing condition of the LOI is that no convertible securities of the Company will be outstanding prior to, or upon, closing (subject to approval of the preferred shareholders) which creates two distinct timing scenarios for the settlement of the preferred securities: prior to, or at closing, pursuant to the terms of the LOI or after closing in the event the transaction proposed by the LOI is not completed. Given the disparate timing conditions, the valuation included two scenarios in the Monte Carlo valuation analysis as of December 31, 2025 and December 23, 2025: Closing and No Closing. The Closing scenario includes settlement logic for the preferred securities based on the profit-maximizing outcome of the preferred shareholder at the hypothetical closing date. The No Closing scenario models the embedded derivatives as if there was no forced conversion event (similar to valuation analyses of the embedded derivatives as of their original issuance and September 30, 2025). The closing scenario resulted in higher warrant values primarily due to a higher implied equity value, a shorter expected time to liquidity, and changes to the post-transaction capital structure and holder economics relative to the no-closing scenario.

The table below shows the inputs used to determine the fair value of the derivative liabilities:

The table below shows the inputs used to determine the fair value of the warrant liabilities:

The Limited Waiver Agreement executed on December 23, 2025 resulted in reclassification of the warrants to equity, the warrant liability was remeasured using inputs as of December 23, 2025, and no subsequent liability remeasurement was required through December 31, 2025.

The following table presents information about the Company’s derivative liabilities and warrant liabilities that are measured at fair value on a recurring basis as of December 31, 2025 and September 22, 2025, and indicates the fair value hierarchy of the valuation inputs the Company utilized to determine such fair value:

The following table sets forth a summary of the change in the fair value of the derivative liabilities and warrant liabilities that are measured at fair value on a recurring basis for the year ended December 31, 2025:

Series E derivative liabilities and warrant liabilities

On October 1, 2025, the Company completed a private placement transaction with institutional investors, resulting in the issuance of Series E convertible preferred stock and accompanying warrants to purchase shares of common stock. In connection with this transaction, the Company recorded warrant liabilities related to the Series E Warrants and derivative liabilities associated with certain embedded features in the Series E Preferred Stock. These instruments were classified as liabilities and measured at fair value in accordance with ASC 815 due to their settlement provisions and other contractual terms. Refer to Note 9 for further detail on the private placement transaction.

The Company measures its bifurcated embedded derivative liability and warrant liability as of December 31, 2025 and issuance, at fair value on a recurring basis using level 3 inputs. These financial instruments are measured using management’s best estimate of fair value, where the inputs into the determination of fair value require significant management judgment to estimation. The derivative liability and warrant liability were both measured using Monte Carlo valuation models. Valuations based on unobservable inputs are highly subjective and require significant judgments. Changes in such judgments could have a material impact on fair value estimates.

As of December 11, 2025 the Company had entered a letter of intent with Realbotix (“LOI”), which contemplates a change of control transaction. A closing condition of the LOI is that no convertible securities of the Company will be outstanding prior to, or upon, closing (subject to approval of the preferred shareholders) which creates two distinct timing scenarios for the settlement of the preferred securities: prior to, or at closing, pursuant to the terms of the LOI or after closing in the event the transaction proposed by the LOI is not completed. Given the disparate timing conditions, the valuation included two scenarios in the Monte Carlo valuation analysis as of December 31, 2025 and December 23, 2025: Closing and No Closing. The Closing scenario includes settlement logic for the preferred securities based on the profit-maximizing outcome of the preferred shareholder at the hypothetical closing date. The No Closing scenario models the embedded derivatives as if there was no forced conversion event (similar to valuation analyses of the embedded derivatives as of their original issuance and September 30, 2025). The closing scenario resulted in higher warrant values primarily due to a higher implied equity value, a shorter expected time to liquidity, and changes to the post-transaction capital structure and holder economics relative to the no-closing scenario.

The table below shows the inputs used to determine the fair value of the derivative liabilities:

The table below shows the inputs used to determine the fair value of the warrant liabilities:

The Limited Waiver Agreement executed on December 23, 2025 resulted in reclassification of the warrants to equity, the warrant liability was remeasured using inputs as of December 23, 2025, and no subsequent liability remeasurement was required through December 31, 2025.

The following table presents information about the Company’s derivative liabilities and warrant liabilities that are measured at fair value on a recurring basis as of December 31, 2025 and October 1, 2025, and indicates the fair value hierarchy of the valuation inputs the Company utilized to determine such fair value:

The following table sets forth a summary of the change in the fair value of the derivative liabilities and warrant liabilities that are measured at fair value on a recurring basis for the year ended December 31, 2025:

Note 9 — Convertible Redeemable Preferred Stock and Stockholders’ Equity

Authorized Capital

As of December 31, 2025 and 2024, the Company is authorized to issue 250,000,000 shares and 10,000,000 shares of common stock and preferred stock, respectively, with a par value of $0.00001 for both common stock and preferred stock.

At December 31, 2025 and 2024, the Company had designated 1,150,000 shares,10,000 shares,2,700,000 shares, and 10,000 shares of Series Seed Preferred Stock, Series A Preferred Stock, Series B Preferred Stock and Series C Preferred Stock, respectively. At December 31, 2025, the Company had designated 32,000 shares and 10,000 shares of Series D and E Preferred Stock, respectively.

Preferred Stock

Series Seed Convertible Preferred Stock

The Company has 1,150,000 shares of preferred stock designated as Series Seed Preferred Stock (“Series Seed”) and there areno shares of Series Seed outstanding as of December 31, 2025 and 2024.

Series A Convertible Preferred Stock

On September 29, 2023, the Company filed a Certificate of Designations of Rights and Preferences of Series A Preferred Stock of the Company (the “Series A Certificate of Designations”) with the State of Delaware to designate and authorize the issuance of up to 10,000 shares of Series A Preferred Stock.

On October 3, 2023, the Company issued 3,000 shares of Series A Convertible Preferred Stock in exchange for the settlement of $3.0 million in notes payable due to Veru, Inc.

On September 24, 2024, Veru converted all 3,000 shares of Series A Convertible Preferred Stock into 1,679 shares of the Company’s common stock per the stated conversion ratio. There were no shares of Series A Convertible Stock outstanding as of December 31, 2025 and 2024.

Series B Convertible Preferred Stock

In connection with the PMX acquisition on December 15, 2023, the Company issued 2,696,729 shares of Series B Convertible Preferred Stock, which were initially convertible into approximately 79,315 shares of common stock, subject to stockholder approval on September 5, 2024. All Series B Preferred Stock was fully converted into common stock on September 24, 2024. As of December 31, 2024 and 2025, no Series B Preferred Stock remains outstanding.

Series C Convertible Preferred Sock

On October 1, 2024, the Board of Directors authorized the Company to create a series of 10,000 shares of preferred stock designated as “Series C Convertible Preferred Stock”, with a par value of $0.00001, pursuant to the certificate of designations. At any time after the initial issuance date of Series C convertible Preferred Stock, each Preferred Share shall be convertible into validly issued, fully paid and non-assessable shares of Common Stock. The holders of Series C Preferred Stock are entitled to dividends, on an as-if converted basis, equal to and in the same form as dividends actually paid on shares of Common Stock, when and if actually paid. In addition, from and after the occurrence and during the continuance of any Triggering Event, dividends (“Default Dividends”) will accrue on the Stated Value of each Preferred Share at a rate of fifteen percent (15.0%) (the “Default Rate”) per annum. Each holder is entitled to convert any portion of the outstanding Preferred Shares held by such holder into validly issued, fully paid and non-assessable Conversion shares at the Conversion Rate, which can be determined by dividing (x) the Conversion Amount of such Preferred Share by (y) the Conversion Price, $4.5056, subject to adjustment as provided in the Certificate of Designations.

After the Stockholder Approval Date, if a Triggering Event occurs and is continuing at any time after the earlier of the holders’ receipt of a Triggering Event Notice and such holder becoming aware of such Triggering Event (such earlier date, the “Alternate Conversion Right Commencement Date”) and ending on the twentieth (20 th) Trading Day after the later of (x) the date of such Triggering Event is cured and (y) such holder’s receipt of a Triggering Event Notice (such ending date, the “Alternate Conversion Right Expiration Date”), and each such period, an “Alternate Conversion Right Period”), such holder may, at such holder’s option, by delivery of a Conversion Notice to the Company (the date of any such Conversion Notice, each an “Alternate Conversion Date”), convert all, or any number of Preferred Shares held by such holder into shares of Common Stock at the Alternate Conversion Price (each, an “Alternate Conversion”). Alternate Conversion Price means, with respect to any Alternate Conversion that price will be the lowest of(i) the applicable Conversion Price as in effect on the applicable Conversion Date of the applicable Alternate Conversion, and (ii) the greater of (x) the Floor Price and (y) 80% of the lowest VWAP of the Common Stock during the five (5) consecutive Trading Day period ending and including the Trading Day immediately preceding the delivery or deemed delivery of the applicable Conversion Notice (such period, the “Alternate Conversion Measuring Period”).

At any time, the Company has the right to redeem in cash all, but not less than all, of the Preferred Shares then outstanding at a price (the “Company Optional Redemption Price”) equal to 125% of the greater of (i) the Conversion Amount being redeemed and (ii) the product of (1) the Conversion Rate with respect to the Conversion Amount being redeemed multiplied by (2) the greatest closing sale price of the Company’s Common Stock on any Trading Day during the period commencing on the date immediately preceding the date the Company notifies the holders of its elections to redeem and the date the Company makes the entire payment required. Upon the occurrence of a Bankruptcy Triggering Event, the Company will immediately redeem, in cash, each of the Preferred Shares then outstanding at a redemption price equal to the greater of (i) the product of (A) the Conversion Amount to be redeemed multiplied by (B) 125% and (ii) the product of (X) the Conversion Rate with respect to the Conversion Amount in effect immediately following the date of initial public announcement of such Bankruptcy Triggering Event multiplied by (y) the product of (1) 125% multiplied by (2) the greatest closing sale price of the Common Stock on any Trading Day during the period commencing on the date immediately preceding such Bankruptcy Triggering Event and ending on the date the Company pays the entire payment required. The holders of the Series C Preferred Stock are entitled to be paid a cash amount equal to 30% of the gross proceeds in the event of any sale of common stock under the ELOC in accordance with the terms stated below within the ELOC securities purchase agreement.

In no event may any Preferred Shares be converted (or Warrants be exercised) and shares of Common Stock be issued to any holder if after giving effect to the issuance of shares of Common Stock upon such conversion of the Preferred Shares (or exercise of the Warrants), the holder (together with its affiliates, if any) would beneficially own more than 4.99% of the outstanding shares of Common Stock, which we refer to herein as the “PIPE Blocker”. The PIPE Blocker may be raised or lowered to any percentage not in excess of 9.99% at the option of the applicable holder of the Preferred Shares (or Warrants), except that any raise will only be effective upon 61-days’ prior notice to the Company.

On July 16, 2025, the Company exercised its voluntary Series C Preferred Stock adjustment right to lower the conversion price of the Series C Preferred Stock to $3.50, and holders of 1,920 shares of Series C Preferred Stock agreed to convert their shares into shares of Common Stock. During the year ended December 31, 2025,1,369 shares of Series C Preferred Stock were redeemed for an aggregate amount of $1.71 million,1,920 shares of Series C Preferred Stock were converted into common stock and 203 shares of Series C Preferred Stock were exchanged into 244 shares of Series D Preferred Stock (as defined below). There wereno redemptions or conversions of the Series C Preferred Stock during the year ended December 31, 2024. As of December 31, 2025,7 shares of Series C Preferred Stock remain outstanding, with a carrying value of $1.7 thousand, as reflected in the accompanying consolidated balance sheet. As of December 31, 2024,3,499 shares of Series C Preferred stock were outstanding with a carrying value of $1.1 million, as reflected in the accompanying consolidated balance sheet.

Series D Preferred Stock

On September 22, 2025, the Company entered into a securities purchase agreement (the “Series D Securities Purchase Agreement” and the financing contemplated therein, the “Series D PIPE Financing”) with eleven institutional investors, and sold or exchanged debt, to such investors (collectively, the “Series D PIPE Investors”) an aggregate of 16,099 shares of Series D convertible preferred stock, par value $0.00001 per share (“Series D Preferred Stock”), which includes an issuance of 500 shares of Series D Preferred Stock to the lead investor in consideration for the Series D PIPE Investors’ irrevocable commitment to purchase shares of the Series D Preferred Stock, and warrants (the “Series D Warrants”) to purchase 4,362,827 shares of Common Stock, (the Series D Preferred Stock together with the Series D Warrants, the “Series D PIPE Securities”), for an aggregate purchase price of approximately $12.9 million and net cash proceeds of $9.3 million. The exercise price of the Series D Warrants is $3.6896, and the Series D Warrants are exercisable beginning on the issuance date and expire on the third anniversary of the issuance date.

Concurrently with entering into the Securities Purchase Agreement, the Company also entered into a registration rights agreement with the Series D PIPE Investors, pursuant to which it has agreed to provide the Series D PIPE Investors with certain registration rights related to the shares of Common Stock underlying the shares of Series D Preferred Stock and Series D Warrants.

In connection with the Series D financing entered into on September 22, 2025, the Company utilized the proceeds to extinguish the outstanding Veru and Keystone notes payable upon the transfer of the settlement considerations. The extinguishment was achieved through a combination of cash payment and the issuance of Series D Preferred Stock and Series D Warrants (See Note 6). The transaction was accounted for as a debt extinguishment in accordance with ASC 405-20 and ASC 470-50. The Company derecognized the carrying amounts of the notes payable and recognized a gain or loss on extinguishment equal to the difference between the reacquisition price, measured at the fair value of the cash and equity instruments transferred, and the net carrying value of the debt. The Company recognized a loss on extinguishment related to this transaction of $5,384,719 recorded within loss on extinguishment of notes payable in the accompanying consolidated statement of operations and comprehensive loss for the year ended December 31, 2025.

The Series D Preferred Stock was determined to be more akin to an equity-like host than a debt-like host and was classified as permanent equity as it was not redeemable in any manner that would require classification outside of permanent equity pursuant to ASC 480-10-S99. The Series D Preferred Stock was recorded on the accompanying consolidated balance sheet at its par value. Certain embedded share-settled redemption features within the Series D Preferred Stock were bifurcated and accounted for separately a derivative liability.

The Series D Warrants and certain embedded share-settled redemption features of the Series D Preferred Stock issued were determined to be liability-classified instruments pursuant to ASC 480 and ASC 815. The embedded features of the Series D Preferred Stock were bifurcated and accounted for separately as derivative liabilities. The Company measured the warrant liabilities and bifurcated derivative liabilities at fair value on a recurring basis using Level 3 inputs as of September 22, 2025 (the issuance date), December 23, 2025 (amended warrants date), and December 31, 2025 (derivative liabilities fair value date), respectively. The fair value of the derivative liabilities was $772,000 and $4,581,333 as of September 22, 2025 and December 31, 2025, respectively. The fair value of the warrant liabilities was $14,749,000 and $4,371,362 as of September 22, 2025 and December 23, 2025, respectively. See Note 8 for further information regarding the valuation methodology and assumptions used in determining the fair value of the warrant and derivative liabilities.

In connection with the Series D PIPE Financing, the Company incurred direct and incremental expenses of $775,000, comprised of legal fees and success fees, were expensed immediately. In addition to these issuance costs, the Company recognized a significant loss on issuance due to the fair value allocation requirements under US GAAP. Specifically, because the Series D Warrants and certain embedded features of the Series D Preferred Stock were determined to be liability-classified instruments pursuant to ASC 480 and ASC 815, they were initially measured at fair value upon issuance. The aggregate fair value of the Warrants $14,749,000 and the bifurcated derivative liabilities related to the Preferred Stock $772,000, as determined by a third-party valuation specialist using a Monte Carlo simulation, exceeded the total gross proceeds received in the Series D PIPE Financing of $12,977,671. As required by the guidance in ASC 470-20-25-2, when the fair value of financial liabilities required to be measured at fair value exceeds the net proceeds received, the excess is recognized as a loss in earnings at issuance. Accordingly, the Company recognized a loss on issuance of $2,543,329, representing the excess of the fair value of the liability-classified instruments over the proceeds allocated to the transaction.

The Series D Preferred Stock hasno voting rights. The Series D Preferred Stock are convertible into common stock at the election of the holders of the Series D Preferred Stock at any time at an initial conversion price of $3.6896 per share. The conversion price is subject to customary adjustments for stock dividends, stock splits, reclassifications, stock combinations and the like (subject to certain exceptions), anti-dilution provisions, and a floor price of $0.74.

The Series D Preferred Stock is not redeemable by the holder except in the event of 1) a liquidation, dissolution, or winding up, or 2) the Series D Preferred Stock is redeemable for common stock of the Company upon the occurrence of a change in control. Holders of the Series D Preferred Stock shall be entitled to receive dividends as authorized and declared by the Company’s Board of Directors, payable in cash, securities, or in other assets as determined by the Company’s Board of Directors.

In the event of the Company’s liquidation, dissolution, or winding up, holders of the Series D Preferred Stock will be entitled to receive out of the assets, whether capital or surplus, an amount equal to the stated value of the Series D Preferred Stock, plus any accrued and unpaid dividends thereon and any other fees or liquidated damages owed before any distribution or payment shall be made to the holders of any junior securities.

During the year ended December 31, 2025, the Company issued 16,343 in connection with the Series D financing, which includes the 16,099 initially issued and an additional 244 shares that were exchanged from Series C Preferred Stock to Series D Preferred Stock, and converted approximately 18 Series D Preferred Stock into common shares. As of December 31, 2025,16,325 shares of Series D Preferred Stock remain outstanding.

Series E Preferred Stock

On October 1, 2025, Onconetix entered into, and sold to institutional investor(s) (collectively, the “PIPE Investors”), pursuant to a securities purchase agreement (the “Securities Purchase Agreement”) an aggregate of 7,813 shares of Series E convertible preferred stock, par value $0.00001 per share (“Series E Preferred Stock”), which are convertible into common stock of the Company, $0.00001 par value per share (the “Common Stock”) and warrants to purchase 2,025,223 shares of Common Stock (the “Warrants” and, together with the Series E Preferred Stock, the “PIPE Securities”), for an aggregate purchase price of approximately $6.25 million and net cash proceeds of $6.2 million. Such investment is referred to as the “PIPE Financing”. The exercise price of the Series E Warrants is $3.8576, and the Series E Warrants are exercisable beginning on the issuance date and expire on the third anniversary of the issuance date.

Concurrently with entering into the Securities Purchase Agreement, the Company also entered into a registration rights agreement with the Series E PIPE Investors, pursuant to which it has agreed to provide the Series E PIPE Investors with certain registration rights related to the shares of Common Stock underlying the shares of Series E Preferred Stock and Series E Warrants.

The Series E Preferred Stock was determined to be more akin to an equity-like host than a debt-like host and was classified as permanent equity as it was not redeemable in any manner that would require classification outside of permanent equity pursuant to ASC 480-10-S99. The Series E Preferred Stock was recorded on the accompanying consolidated balance sheet at its par value. Certain embedded share-settled redemption features within the Series E Preferred Stock were bifurcated and accounted for separately a derivative liability.

The Series E Warrants and certain embedded share-settled redemption features of the Series E Preferred Stock issued were determined to be liability-classified instruments pursuant to ASC 480 and ASC 815. The embedded features of the Series E Preferred Stock were bifurcated and accounted for separately as derivative liabilities. The Company measured the warrant liabilities and bifurcated derivative liabilities at fair value on a recurring basis using Level 3 inputs as of October 1, 2025 (the issuance date), December 23, 2025 (amended warrants date) , and December 31, 2025 (derivative liabilities fair value date). The fair value of the derivative liabilities was $865,000 and $2,404,014 as of October 1, 2025 and December 31, 2025, respectively. The fair value of the warrant liabilities was $6,516,000 and $2,029,153 as of October 1, 2025 and December 23, 2025, respectively. See Note 8 for further information regarding the valuation methodology and assumptions used in determining the fair value of the warrant and derivative liabilities.

In connection with the Series E PIPE Financing, the Company incurred direct and incremental expenses of $60,000, comprised of legal fees and success fees, were expensed immediately. In addition to these issuance costs, the Company recognized a significant loss on issuance due to the fair value allocation requirements under US GAAP. Specifically, because the Series E Warrants and certain embedded features of the Series E Preferred Stock were determined to be liability-classified instruments pursuant to ASC 480 and ASC 815, they were initially measured at fair value upon issuance. The aggregate fair value of the Warrants $6,516,000 and the bifurcated derivative liabilities related to the Preferred Stock $865,000, as determined by a third-party valuation specialist using a Monte Carlo simulation, exceeded the total gross proceeds received in the Series E PIPE Financing of $6,250,000. As required by the guidance in ASC 470-20-25-2, when the fair value of financial liabilities required to be measured at fair value exceeds the net proceeds received, the excess is recognized as a loss in earnings at issuance. Accordingly, the Company recognized a loss on issuance of $1,131,000, representing the excess of the fair value of the liability-classified instruments over the proceeds allocated to the transaction.

The Series E Preferred Stock hasno voting rights. The Series E Preferred Stock are convertible into common stock at the election of the holders of the Series E Preferred Stock at any time at an initial conversion price of $3.8576 per share. The conversion price is subject to customary adjustments for stock dividends, stock splits, reclassifications, stock combinations and the like (subject to certain exceptions), anti-dilution provisions, and a floor price of $0.7715.

The Series E Preferred Stock is not redeemable by the holder except in the event of 1) a liquidation, dissolution, or winding up, or 2) the Series E Preferred Stock is redeemable for common stock of the Company upon the occurrence of a change in control. Holders of the Series E Preferred Stock shall be entitled to receive dividends as authorized and declared by the Company’s Board of Directors, payable in cash, securities, or in other assets as determined by the Company’s Board of Directors.

In the event of the Company’s liquidation, dissolution, or winding up, holders of the Series E Preferred Stock will be entitled to receive out of the assets, whether capital or surplus, an amount equal to the stated value of the Series E Preferred Stock, plus any accrued and unpaid dividends thereon and any other fees or liquidated damages owed before any distribution or payment shall be made to the holders of any junior securities.

During the year ended December 31, 2025, the Company issued 7,813 in connection with the Series E financing. As of December 31, 2025,7,813 shares of Series E Preferred Stock remain outstanding.

Warrant Waiver Amendment Reclassification

On December 23, 2025, the Company executed a Limited Waiver Agreement (the “Limited Waiver”) effective October 1, 2025, that amended the September 2025 Series D and October 2025 Series E investor warrants of an aggregate of 6,388,050 warrants (the “Amended Warrants”), including removal of the issuer-specific cash settlement upon certain Fundamental Transactions and a change to treat holders pari passu with common shareholders. Management concluded the Amended Warrants no longer embody an obligation to transfer assets under ASC 480 and, after evaluating exercise/settlement terms (including anti-dilution, buy-in, authorized-share-failure, and beneficial-ownership caps), determined they are indexed to the Company’s stock and meet equity-classification conditions under ASC 815-40. Accordingly, the warrants were remeasured at fair value and reclassified to equity on December 23, 2025. Because the amendment moved the instruments from liability to equity, the Company recognized a gain of approximately $14.9 million for the change in fair value on December 23, 2025, and reclassified $6.4 million (aggregate fair value) to additional paid-in capital. The reclassification resulted in a non-cash adjustment to the Company’s balance sheet, reducing warrant liabilities and increasing additional paid-in capital. No subsequent remeasurement of the Warrants will be required so long as they remain equity-classified. After reclassification to equity, the Amended Warrants are not remeasured.

October 2024 Securities Purchase Agreement and ELOC

On October 2, 2024, the Company entered into a Securities Purchase Agreement (the “Series C Securities Purchase Agreement”) with six institutional and accredited investors. The Company sold an aggregate of i)3,499 Series C Preferred Stock, par value $0.00001 per, and (ii) a warrants to purchase 6,963 shares of common stock (the “Series C PIPE Warrants”), for aggregate cash proceeds of $2,000,000. The Series C Warrants have an exercise price of $372.30 per share, subject to adjustment therein, and expire on the third anniversary of the initial exercisability date. The warrants issued with the Series C Redeemable Preferred Stock are accounted for as liabilities in accordance with ASC 815.

Concurrently, on October 2, 2024, the Company entered into a Common Stock Equity Line of Credit Purchase Agreement (the “ELOC Purchase Agreement” and the equity line of credit, the “ELOC”) with an institutional investor, whereby the Company may sell up to $25,000,000 of the Company’s new issued Common Stock. Pursuant to the ELOC Purchase Agreement, the investor shall purchase from the Company up to the lesser of (i) $25.0 million in shares of our Common Stock and (ii)19,512 shares, representing 19.99% of the total number of shares of Common Stock outstanding immediately prior to the execution of the ELOC Purchase Agreement. Pursuant to the ELOC Purchase Agreement,30% of the gross proceeds to the Company from any sale of common stock thereunder must be applied towards the redemption of the Series C Redeemable Preferred Stock.

Based on the terms of the Series C Redeemable Preferred Stock and the Company’s Certificate of Designation, and in accordance with ASC 480, the Series C Redeemable Preferred Stock is accounted for as mezzanine equity due to the contingent redemption feature upon any sale of common stock under the ELOC Purchase Agreement. The initial cash proceeds of $2,000,000 were allocated between the Series C Preferred Stock and derivative liability warrants, with the amount initially recorded in mezzanine equity based on the guidance in ASC 815 (i.e. the value of the derivative liability warrant is allocated its full fair value, and the residual is allocated to the Series C Redeemable Preferred Stock). The derivative liability warrants were measured at fair value at inception in the amount of $1,138,476 and the Series C Redeemable Preferred stock was measured at residual value of $861,524. The Series C Redeemable Preferred Stock is subsequently measured at redemption value as they occur, with the difference between the basis per share of $246.22 and redemption value per share recorded as a deemed dividend in the statements of operations.

During the year ended December 31, 2024, the Company received proceeds of $935,625 and recorded approximately $250,000 of shareholder receivable under the ELOC. In addition, the Company recorded a deemed divided in the amount of $206,404 in the consolidated statement of operations for the year ended December 31, 2024.

During the year ended December 31, 2025, the Company received proceeds of $6,391,655 under the ELOC and recorded a deemed divided in the amount of $1,498,595 in the consolidated statement of operations.

Common Stock

As of December 31, 2025 and 2024 there were 1,560,153 and 138,422 shares of common stock issued, respectively, and 1,560,001 and 138,270 shares of common stock outstanding, respectively.

Warrant Inducements:

July 2024 Inducement

On July 11, 2024, the Company entered into common stock preferred investment options exercise inducement offer letters (the “Inducement Letters”) with certain holders of existing preferred investment options to purchase shares of the Company’s common stock at exercise prices of $8,656.40 and $3,706.00 per share, issued on August 11, 2022 and August 2, 2023, respectively (collectively, the “Existing PIOs”), pursuant to which the holders agreed to exercise for cash their Existing PIOs to purchase an aggregate of 2,193 shares of the Company’s common stock, at a reduced exercise price of $510 per share, in consideration for the Company’s agreement to issue new preferred investment options (the “Inducement PIOs”) to purchase up to an aggregate of 6,580 shares of the Company’s common stock. Of the 6,580 PIOs issued,2,193 have a contractual term of 5 years, while the remaining 4,387 have a contractual term of 2 years. Aside from the contractual terms, the Inducement PIOs have substantially the same terms as the Existing PIOs.

On July 11, 2024, the Company consummated the transaction contemplated by the Inducement Letters upon unanimous written consent of the Board of Directors (the “Warrant Inducement”). The Company received aggregate net proceeds of approximately $0.9 million from the Warrant Inducement, after deducting placement agent fees and other offering expenses payable by the Company.

The Company agreed to file a registration statement covering the resale of the Inducement PIO Shares issued or issuable upon the exercise of the Inducement PIOs (the “Resale Registration Statement”) within 30 days after the date of the Inducement Letter and to use commercially reasonable efforts to cause such Resale Registration Statement to be declared effective by the SEC within 60 days following the date of the Inducement Letter (or within 90 days following the date of the Inducement Letter in the case of full review of the Resale Registration Statement by the SEC).

The Company engaged H.C. Wainwright & Co., LLC (“Wainwright”) to act as its exclusive placement agent in connection with the transactions summarized herein and paid Wainwright a cash fee equal to 7.5% of the gross proceeds received form the exercise of the Existing PIOs as well as a management fee equal to 1.0% of the gross proceeds from the exercise of the Existing PIOs. The Company also agreed to reimburse Wainwright for its expenses in connection with the exercise of the Existing PIOs and the issuance of the Inducement PIOS, up to $50,000 for fees and expenses of legal counsel and other out-of-pocket expenses and paid Wainwright for non-accountable expenses in the amount of $35,000. The Company also issued to Wainwright or its designees warrants (the “Placement Agent Warrants”), and as such shares of common stock issuable thereunder, (the “Placement Agent Warrant Shares”) to purchase (i)154 shares of common stock which have the same terms as the Inducement PIOs except for an exercise price equal to $637.50 per share and a term offive (5) years following the date of stockholder approval and (ii) upon any exercise for cash of the Inducement PIOs,7.5% of the aggregate exercise price and that number of shares of common stock equal to 7.0% of the aggregate number of such shares of common stock underlying the Inducement PIOs that have not been exercised, which will have substantially the same terms as the Placement Agent Warrants.

The Company evaluated the terms of the Inducement PIOs and the Wainwright Inducement Warrants (collectively, the “August 2023 Inducement Warrants”), and determined that they should be classified as equity instruments based upon accounting guidance provided in ASC 480 and ASC 815-40.

The Warrant Inducement, which resulted in the lowering of the exercise price of the Existing PIOs and the issuance of the Inducement PIOs, is considered a modification of the Existing PIOs under the guidance of Accounting Standards Update (“ASU”) No. 2021-04,Issuer’s Accounting for Certain Modifications or Exchanges of Equity Classified Written Call Options. The modification is consistent with the “Equity Issuance” classification under that guidance as the reason for the modification was to induce the holders of the Existing PIOs to cash exercise their warrants, resulting in the imminent exercise of the Existing PIOs, which raised equity capital and generated net proceeds for the Company of approximately $0.9 million. As the Existing PIOs and the Inducement PIOs were classified as equity instruments before and after the exchange, and as the exchange is directly attributable to an equity offering, the Company recognized the effect of the modification of approximately $1.9 million as an equity issuance cost.

In addition, the change in fair value of the contingent warrant liability associated with 44 of the August 2022 Contingent Warrants and 88 of the August 2023 Contingent Warrants was decreased to $0 upon the agreement with Wainwright that all prior contingent warrants were no longer issuable or due upon the Warrant Inducement Transaction. The fair value of the contingent warrant liability of approximately $2,700 was derecognized as of the settlement date, with the corresponding amount, representing the fair value of the Wainwright Inducement Warrants, was recognized as additional paid-in capital.

The Company evaluated the terms of the 461 Inducement Contingent Warrants (equivalent to 7.0% of the aggregate number of such shares of common stock underlying the Inducement PIOs that have not been exercised), which are issuable upon a future inducement, and determined that they should be classified as a liability based upon accounting guidance provided in ASC 815-40. Since the Inducement Contingent Warrants are a form of compensation to Wainwright, the Company recorded the value of the liability of approximately $158,000 as a reduction of additional paid in capital, with subsequent changes in the value of the liability recorded in other income (expense) in the accompanying statements of operations. The fair value was determined using a Monte-Carlo option pricing model, and as of December 31, 2025 and 2024

Treasury Stock

On November 10, 2022, the Board approved a stock repurchase program (the “Repurchase Program”) to allow the Company to repurchase up to 125,000 shares of common stock with a maximum price of $1.00 per share, with discretion to management to make purchases subject to market conditions. On November 18, 2022, the Board approved an increase to the maximum price to $2.00 per share. There was no expiration date for this program and prices are not adjusted for the reverse stock split to comply with the program.

There wereno repurchases of common stock during the years ended December 31, 2025 and 2024.

On November 13, 2024, the Board terminated the Repurchase Program.

At the Market Offering Agreement

Deferred offering costs associated with the ATM Agreement are reclassified to additional paid in capital on a pro-rata basis when the Company completes offerings under the ATM Agreement. Any remaining deferred costs will be expensed to the statements of operations should the planned offering be abandoned.

As of December 31, 2025 and 2024, no shares have been sold under the ATM Offering, and the Company wrote off approximately $0.3 million of deferred offering costs in its consolidated balance sheets as of December 31, 2024.

Warrants

The following summarizes activity related to the Company’s outstanding warrants, excluding contingent warrants issuable upon exercise of the preferred investment options, for the years ended December 31, 2025 and 2024:

As of December 31, 2025, the Company had outstanding warrants, which are exercisable into 6,401,875 shares of common stock. The shares of common stock underlying the warrants outstanding had an exercise price of $4.97 per share.

Contingent Warrant Liabilities

As of December 31, 2025, the fair value of contingent warrant labilities includes the Series C Warrants of $6,300 and those issuable upon exercise of the Inducement PIOs of approximately $20,290 totaling $26,590 included as contingent warrant liabilities in the accompanying consolidated balance sheets.

As of December 31, 2024, the fair value of contingent warrant labilities includes the Series C Warrants of $32,982 and those issuable upon exercise of the Inducement PIOs of approximately $10,200 totaling $43,089 included as contingent warrant liabilities in the accompanying consolidated balance sheets.

Onconetix Equity Incentive Plans

The Company’s 2019 Equity Incentive Plan (the “2019 Plan”) was adopted by its board of directors and by its stockholders on July 1, 2019. On February 23, 2022 the Company’s board of directors adopted the Company’s 2022 Equity Incentive Plan (the “2022 Plan”), which is the successor and continuation of the Company’s 2019 Plan. Under the 2022 Plan, the Company may grant stock options, restricted stock, restricted stock units, stock appreciation rights, and other forms of awards to employees, directors, and consultants of the Company. In May 2023, the number of shares of common stock reserved for issuance under the 2022 Plan was increased to 926, and in September 2024, the number of shares of common stock reserved for issuance under the 2022 Plan was increased to 17,058. Stock-based awards granted during the years ended December 31, 2025 and 2024 were all granted under the 2022 Plan. As of December 31, 2025, there are 7,899 shares available for issuance under the 2022 Plan.

Note 9 — Convertible Redeemable Preferred Stock and Stockholders’ Equity(cont.)

Stock Options

The following summarizes activity related to the Company’s stock options under the 2019 Plan and the 2022 Plan for the years ended December 31, 2025 and 2024:

There wereno stock options granted during the years ended December 31, 2025 and 2024.

The aggregate fair value of stock options that vested during the year ended December 31, 2025 and 2024, was approximately $0.01 million and $0.7 million, respectively.

Note 9 — Convertible Redeemable Preferred Stock and Stockholders’ Equity(cont.)

Restricted Stock

On May 9, 2023, the Board’s Compensation Committee approved the issuance of restricted stock, granted under the Company’s 2022 Plan, to the Company’s executive officers, employees, and certain of the Company’s consultants. The restricted shares granted totaled 143, of which 44,22, and 44 were granted to the Company’s former CEO, former CFO, and former CBO, respectively. All of the restricted shares granted vest as follows:50% in January 2024,25% in August 2024, and 25% in August 2025. In addition, on May 31, 2023, the Board’s Compensation Committee approved the issuance of 7 shares of restricted stock, granted to the Company’s non-executive Board members, with full vesting on May 31, 2024. On February 14, 2024, in connection with the appointment of a non-executive Board member, the Company issued 1 share of restricted stock, which vested in full on June 14, 2024. Furthermore, on September 26, 2024, the Company issued its Board members a total of 195 restricted stock, with full vesting August 31, 2025. On February 24, 2025, in connection with the appointment of an executive Board member, the Company issued 20 shares of restricted stock with full vesting August 31, 2025. Subsequently, the Company modified the vesting date of 137 shares previously issued to the Board members to provide for full vesting August 31, 2026. On August 15, 2025, the Company issued its Board members a total of 2,472 restricted stock, with full vesting August 16, 2026.

The following summarizes activity related to the Company’s restricted stock awards granted under the 2022 Plan for the year ended December 31, 2025:

Proteomedix Stock Option Plan

Proteomedix sponsors a stock option plan (the “PMX Option Plan”) which provides common stock option grants to be granted to certain employees and consultants, as was determined by the board of directors of Proteomedix. In connection with the PMX Transaction, the Company assumed the PMX Option Plan.

Generally, options issued under the PMX Option Plan have a term of not more than 11 years and provide for a four-year vesting period. Stock options issued under the PMX Option Plan are measured at fair value using the Black-Scholes option pricing model.

On April 16, 2024, the board of directors of Proteomedix approved a two-year extension of 144 vested stock options that were set to expire in April 2024. The extended expiration date for these options is April 18, 2026. The Company recorded approximately $18,000 of expense associated with this modification during the year ended December 31, 2024.

There was no activity under the PMX Option Plan for the years ended December 31, 2025 and 2024. In October 2024,684 stock options were converted to shares with a weighted average exercise price of $294.10. As of December 31, 2025 and 2024, there wereno outstanding stock options.

Stock-Based Compensation

Stock-based compensation expense for the years ended December 31, 2025 and 2024 was as follows:

Note 10 — Commitments and Contingencies

Office Lease

Proteomedix leases office and lab space in Zurich Switzerland. On April 1, 2024, the original lease was amended to add additional office and laboratory space. The lease amendment was accounted for as a separate lease, resulting in an additional right-of-use asset and lease liability of approximately $88,000.

In May 2025, Proteomedix entered into a lease amendment to reduce its leased premises. Effective June 30, 2025, the Company terminated the April 2024 lease amendment, which included office space and laboratory space. Additionally, a partial termination of a prior lease amendment further reduced the office space.

This lease expired on December 31, 2025, and was renewed for a successive two-year term, resulting in an additional right-of-use asset and lease liability of approximately $49,000. The lease, as renewed, requires payments of approximately $24,000 over the next twelve months. The lease will automatically renew for successive two-year terms, unless terminated. Either party may terminate the lease with twelve months’ written notice.

Litigation

From time to time, the Company may be subject to various legal proceedings and claims that arise in the ordinary course of its business activities. As of December 31, 2025, the Company is not a party to any material legal proceedings and is not aware of any pending or threatened claims.

Termination of Ocuvex Merger Agreement

On July 16, 2025, the Company entered into an Agreement and Plan of Merger with (i) Onconetix Merger Sub, Inc., a Delaware corporation and a direct, wholly owned subsidiary of the Company, and (ii) Ocuvex Therapeutics, Inc., a Delaware corporation (“Ocuvex”, and such agreement, the “Merger Agreement”). Pursuant to the Merger Agreement, Merger Sub will merge with and into Ocuvex, with Ocuvex surviving the merger as a direct, wholly owned subsidiary of the Company (the “Merger”).

Effective September 24, 2025, pursuant to the terms of the Merger Agreement, the Company and Ocuvex entered into a Termination and Release Agreement (the “Termination Agreement”) pursuant to which they agreed to terminate the Merger Agreement and the transactions contemplated thereby. The Termination Agreement also provides for a mutual release of claims among the Company, Ocuvex and their affiliates and in consideration of the foregoing, the Company agreed to pay to Ocuvex, an amount equal to**$**302,343.55 (the “Termination Payment”), which represents all amounts payable by the Company to Ocuvex pursuant to the terms of the Merger Agreement. The termination payment is recorded within selling, general, and administrative expenses in the accompanying consolidated statement of operations and comprehensive loss for the year ended December 31, 2025.

As of September 24, 2025, Ocuvex confirmed receipt of the Termination Payment, and as a result the Merger Agreement is of no further force and effect.

Registration Rights Agreements

In connection with private placements consummated in April 2022 and August 2022, the Company entered into Registration Rights Agreements with the purchasers. Upon the occurrence of any Event (as defined in each Registration Rights Agreement), which, among others, prohibits the purchasers from reselling the securities for more than ten consecutive calendar days or more than an aggregate of fifteen calendar days during any 12-month period, and should the registration statement cease to remain continuously effective, the Company would be obligated to pay to each purchaser, on each monthly anniversary of each such Event, an amount in cash, as partial liquidated damages and not as a penalty, equal to the product of 2.0% multiplied by the aggregate subscription amount paid by such purchaser in the private placements. As of December 31, 2025 and 2024, and as a result of the consummation of the remaining warrants associated with the April 2022 and August 2022 private placements, the Company has no further obligations pertaining to the Registration Rights Agreements.

Indemnification

In the normal course of business, the Company enters into contracts and agreements that contain a variety of representations and warranties and provide for general indemnifications. The Company’s exposure under these agreements is unknown because it involves claims that may be made against the Company in the future but have not yet been made. To date, the Company has not been required to defend any action related to its indemnification obligations. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is not estimable at this time.

Note 11 — Related Party Transactions

On December 18, 2023, the Company entered into the Subscription Agreement with the PMX Investor, a 5% stockholder of the Company as of December 31, 2025. During the year ended December 31, 2024, the Company issued a non-convertible debenture in the principal amount of $5.0 million to the PMX Investor, in connection with the Subscription Agreement and has settled the principal and accrued interest through the issuance of shares (see Note 6).

On February 6, 2024, the Company appointed Thomas Meier, PhD, as a member of the Company’s board of directors. Dr. Meier provides consulting services to Proteomedix, through a consulting agreement that was effective January 4, 2024. The Company recorded approximately $0 and $58,000 in related expenses during the years ended December 31, 2025 and 2024, respectively. As of December 31, 2025 and 2024, no amounts related to this agreement were included in accounts payable.

On June 17, 2025, the Company entered into a separate consulting agreement with a firm affiliated with Dr. Meier. The agreement provides for the payment of certain success fees and reimbursement of related expenses. Under its terms, Dr. Meier is entitled to earn up to 10% of success fees for transactions greater than $9 million earned by the affiliated firm, payable only upon receipt of such proceeds. The Company recorded approximately $33,000 and $0 in related expenses during the years ended December 31, 2025 and 2024. As of December 31, 2025 and 2024, approximately $16,500 and $0 related to this agreement was included in accounts payable.

Note 12 — Income Taxes

The components of loss before income taxes are as follows:

The Company’s major tax jurisdictions are the United States, Switzerland, and various state jurisdictions, and the Company does not have any pending tax audits. The income tax provision (benefit) recorded for the years ended December 31, 2025 and December 31, 2024 related to the Company’s deferred foreign taxes. Generally, the Company’s federal returns from 2020 on and state returns from 2019 on, and foreign returns from 2019 on, are subject to examination by the United States, state, and foreign tax authorities; however, to the extent allowed by law, tax authorities have the ability to adjust the Company’s carryforwards of unutilized net operating losses and research and development credits for all years.

Note 12 — Income Taxes (cont.)

At December 31, 2025, the Company had a net operating loss (“NOL”) carryforward for federal, foreign, and state income tax purposes totaling approximately $55.2 million, $14.2 million, and $36.0 million, respectively, available to reduce future taxable income. The federal NOL and certain state NOLs of $25.1 million are carried forward indefinitely subject to a limitation of 80% of taxable income. Foreign NOLs and state NOLs of approximately $14.2 million and $11.0 million, respectively will begin to expire in 2025 if not utilized.

The NOL carry forward is subject to review and possible adjustment by the Internal Revenue Service and state tax authorities. Under the Internal Revenue Code (“IRC”) Sections 382 and 383, annual use of the Company’s net operating loss carryforwards and research credit carryforwards to offset taxable income and tax, respectively, may be limited based on cumulative changes in ownership. The Company has not completed an analysis to determine whether any such limitations have been triggered as of December 31, 2025. The amount of the annual limitation, if any, will be determined based on the value of the Company immediately prior to the ownership change. Subsequent ownership changes may further affect the limitation in future years.

The tax effects of the temporary differences and carryforwards that give rise to deferred tax assets and liabilities consist of the following:

The Company has evaluated the positive and negative evidence bearing upon the realizability of its deferred tax assets. The Company has recorded a valuation allowance against its United States federal and state deferred tax assets, as well as a portion of its foreign deferred tax assets in each of the years ended December 31, 2025 and 2024, because the Company’s management believes that it is more likely than not that these assets will not be realized. During the years ended December 31, 2025 and 2024, the valuation allowance decreased by approximately $0.3 million and $4.7 million, respectively.

Note 12 — Income Taxes (cont.)

The provision for income taxes on earnings subject to income taxes differs from the statutory Federal rate at December 31, 2025 and 2024, due to the following:

Under U.S. GAAP, the impact of an uncertain income tax position on the income tax return must be recognized at the largest amount that is more-likely-than-not to be sustained upon audit by the relevant taxing authority. An uncertain income tax position will not be recognized if it has less than a 50% likelihood of being sustained. Additionally, U.S. GAAP provides guidance on derecognition, classification, interest and penalties, accounting for interim periods, disclosure, and transition.

A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows:

At December 31, 2025 and 2024, the Company’s unrecognized tax benefits were $17,713 and $26,462, respectively. Due to the existence of the valuation allowance, future changes in the Company’s unrecognized tax benefits will not impact the effective tax rate. The Company does not expect its unrecognized tax benefits to change significantly over the next 12 months.

The Company’s policy is to recognize interest expense and penalties related to uncertain tax positions as a component of income tax expense. As of December 31, 2025 and 2024, there were no accrued interest and penalties associated with uncertain tax positions.

Note 13 — Net Loss Per Share

Basic net loss per share is computed by dividing the net income or loss applicable to common shares by the weighted average number of common shares outstanding during the period. The weighted average number of shares of common stock outstanding includes pre-funded warrants because their exercise requires only nominal consideration for delivery of shares; it does not include any potentially dilutive securities or any unvested restricted shares of common stock. Certain restricted shares, although classified as issued and outstanding at December 31, 2025, are considered contingently returnable until the restrictions lapse and will not be included in the basic net loss per share calculation until the shares are vested. Unvested shares of the Company’s restricted stock do not contain non-forfeitable rights to dividends and dividend equivalents.

The two-class method is used to determine earnings per share based on participation rights of participating securities in any undistributed earnings. Each share of preferred stock that includes rights to participate in distributed earnings is considered a participating security and the Company uses the two-class method to calculate net income available to the Company’s common stockholders per common share — basic and diluted.

The following securities were excluded from the computation of diluted shares outstanding due to the losses incurred in the periods presented, as they would have had an anti-dilutive impact on the Company’s net loss:

Note 14 — Defined Benefit Plan

Proteomedix sponsors adefined benefit pension plan (the “Swiss Plan”) covering certain eligible employees. The Swiss Plan provides retirement benefits based on years of service and compensation levels. As of December 31, 2025, the Proteomedix defined benefit pension plan was fully terminated and settled. As a result of this settlement, all curtailment and settlement gains have been recognized in the current period. Accordingly, the projected benefit obligation iszero, and there areno remaining assets or liabilities associated with the defined benefit plan as of the reporting date.

The following significant actuarial assumptions were used in calculating the benefit obligation and the net periodic benefit cost as of December 31, 2025 and 2024:

Changes in these assumptions may have a material impact on the plan’s obligations and costs.

The components of net periodic benefit cost for the years ended December 31, 2025 and 2024 are as follows:

During the years ended December 31, 2025 and 2024, Proteomedix made pension contributions of approximately $45,000 and $89,404, respectively.

Note 14 — Defined Benefit Plan (cont.)

The components of change in pension benefit obligation plan for the years ended December 31, 2025 and 2024 are as follows:

As of December 31, 2025, these amounts were fully removed from Accumulated Other Comprehensive Income as a part of the pension settlement and recognized in retained earnings through the net periodic benefit cost above.

As of December 31, 2025 and 2024, the funded status of the plan and the amounts recognized in the accompanying consolidated balance sheet are as follows:

A reconciliation of the beginning and ending balances of the accumulated benefit obligation is provided in the table below:

A reconciliation of the beginning and ending balances of the plan assets is provided in the table below:

Note 15 — Segment Information

The Company conducts its business activities and reports financial results asone business segment. The presentation of financial results asone reportable segment is consistent with the way the Company operates its business and is consistent with the manner in which the Chief Operating Decision Maker ("CODM") evaluates performance and makes resource and operating decisions for the business. The Company’s CODM is the Chief Executive Officer. Furthermore, the Company notes that monitoring financial results as one reportable segment helps the CODM manage costs on a consolidated basis, consistent with the integrated nature of the operations. The CODM uses net loss, as reported on the Consolidated Statements of Operations and Comprehensive Loss, in evaluating performance of the Company and determining how to allocate resources of the Company as a whole. As the CODM evaluates performance on a consolidated basis, all required financial segment information is included in the consolidated financial statements.

Geographic Information

The distribution of revenue by geographical area was as follows:

Note 16 — Subsequent Events

Realbotix Corp. Share Exchange Agreement

On February 11, 2026, we entered into a Share Exchange Agreement (the “Share Exchange Agreement”), by and among (i) Onconetix, (ii) Realbotix Corp., a company existing under the laws of the Province of Ontario (“Parent”), (iii) Simulacra Corporation, a Delaware corporation and a wholly-owned subsidiary of Parent (the “Seller”) and (iv) Realbotix, LLC, a Delaware limited liability company and wholly owned subsidiary of the Seller (the “Realbotix”).

Pursuant to the Share Exchange Agreement, subject to the terms and conditions set forth therein, the Seller agreed to contribute and transfer to us, and we agreed to acquire and accept, all of the issued and outstanding equity interests of Realbotix in exchange for newly issued shares of Common Stock. (the “Share Exchange” and the other transactions contemplated by the Share Exchange Agreement, the “Realbotix Transactions”).

Under the terms of the Share Exchange Agreement, the percentage ownership of Buyer’s fully diluted shares to be received by the Seller upon closing will vary based on Buyer’s net cash at closing, ranging from 75% to 90% of Buyer’s fully diluted shares. The transaction is subject to multiple closing conditions, including, among others, minimum net cash requirements, completion of financing arrangements, receipt of required regulatory and stockholder approvals, delivery of audited financial statements, and the absence of any legal prohibition to consummation of the transaction. The Share Exchange Agreement also includes customary representations, warranties, covenants, and termination provisions, including potential termination fees and reimbursement of transaction expenses under certain circumstances.

As of the date the financial statements were issued, the Share Exchange had not been consummated, and no amounts related to the transaction have been recognized in the accompanying financial statements. The Company will account for the transaction, if and when consummated, in the period in which the closing occurs.

Note 16 — Subsequent Events (cont.)

Investor Relations and Advisory Agreement

On February 11, 2026, in connection with the pending Realbotix transaction, the Company entered into a six-month business advisory and investor relations agreement with MDM Worldwide Solutions, Inc. Under the agreement, the Company will pay MDM $50,000 per month for the first four months and $10,000 per month for the remaining two months, with additional fees for special projects subject to mutual agreement.

Reverse Stock Split

On February 3, 2026, the Company held a special meeting of stockholders (the**“**Special Meeting”), whereby its stockholders approved an amendment to the Company’s Amended and Restated Certificate of Incorporation to effect a reverse stock split of all of the outstanding shares of Common Stock at a ratio in the range of 1-for-2 to 1-for-50, at any time prior to the one-year anniversary date of the Special Meeting, with such ratio to be determined by the Board without further approval or authorization of the Company’s stockholders.

Director & Officer Insurance Policy

On February 17, 2026, the Company entered into a twelve-month insurance policy for its Board of Directors and Officers with total premiums of $330,000, for which a note payable of $247,197 was issued to finance such policy. The principal of the note is expected to be paid off through ten monthly payments of $25,693 starting on March 17, 2026.

Series D and Series E Preferred Stock Conversions

As of March 11, 2026, at the election of their holders,1,916 shares of Series D Preferred Stock had converted into 1,852,715 shares of common stock and 132 shares of Series E Preferred Stock had converted into 176,363 shares of common stock.