DELCATH SYSTEMS, INC.

(amounts in thousands, except share and per share amounts)

(1)General

The unaudited interim condensed consolidated financial statements of Delcath Systems, Inc. (“Delcath” or the “Company”) as of and for the three and six months ended June 30, 2025 and 2024 should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2024 (the “Annual Report”), which was filed with the Securities and Exchange Commission (the “SEC”) on March 6, 2025 and may also be found on the Company’s website (www.delcath.com). In these notes to the interim condensed consolidated financial statements the terms “us”, “we” or “our” refer to Delcath and its consolidated subsidiaries.

Description of Business

The Company is an interventional oncology company focused on the treatment of primary and metastatic cancers to the liver. The Company’s lead product, the HEPZATOTM KIT (melphalan for Injection/Hepatic Delivery System) a drug/device combination product (“HEPZATO” or “HEPZATO KIT”), was approved by the US Food and Drug Administration (the “FDA”) on August 14, 2023, indicated as a liver-directed treatment for adult patients with uveal melanoma with unresectable hepatic metastases affecting less than 50% of the liver and no extrahepatic disease, or extrahepatic disease limited to the bone, lymph nodes, subcutaneous tissues, or lung that is amenable to resection, or radiation. The first commercial use of HEPZATO KIT for the treatment of metastatic uveal melanoma (“mUM”) occurred in January 2024.

In the United States, HEPZATO is considered a combination drug and device product and is regulated as a drug by the FDA. Primary jurisdiction for regulation of HEPZATO has been assigned to the FDA’s Center for Drug Evaluation and Research. The FDA has granted Delcathsix orphan drug designations (five for melphalan in the treatment of patients with ocular (uveal) melanoma, cutaneous melanoma, intrahepatic cholangiocarcinoma, hepatocellular carcinoma, and neuroendocrine tumor indications andone for doxorubicin in the treatment of patients with hepatocellular carcinoma).

The Company has sufficient raw material and component constituent parts of the HEPZATO KIT to meet anticipated demand and it intends to manage supply chain risk through stockpiled inventory and, where commercially reasonable, contracting with multiple suppliers for critical components.

In Europe, the hepatic delivery system is a stand-alone medical device having the same device components as HEPZATO, but without the melphalan hydrochloride and is approved for sale under the trade name CHEMOSAT Hepatic Delivery System for Melphalan (“CHEMOSAT”), where it has been used at major medical centers to treat a wide range of cancers in the liver. On February 28, 2022, CHEMOSAT received Medical Device Regulation (“MDR”) certification under the European Medical Devices Regulation (EU) 2017/745, which may be considered by jurisdictions when evaluating reimbursement. In June 2025, CHEMOSAT was approved for reimbursement fortwo years in the Vastra Gotaland Region in Sweden.

To support the New Drug Application for HEPZATO the Company conducted the FOCUS Clinical Trial for Patients with metastatic hepatic dominant Uveal Melanoma (the “FOCUS Trial”), a global registration clinical trial that investigated objective response rate in patients with mUM. On May 6, 2024, the Company announced the publication of results from the pivotal FOCUS Trial in the journal Annals of Surgical Oncology. In addition, on April 9, 2025, the Company announced the publication of a comparative analysis of the randomized portion of the FOCUS Trial in the Annals of Surgical Oncology. Currently, the Company’s clinical development program is seeking to generate clinical data for CHEMOSAT and HEPZATO either as monotherapy or in combination with immunotherapy. The Company expects that this will support increased clinical adoption of and reimbursement for CHEMOSAT in Europe, and to support reimbursement in various jurisdictions, including the United States.

In addition to HEPZATO’s use to treat mUM, the Company believes that HEPZATO has the potential to treat other cancers in the liver, such as metastatic colorectal cancer, metastatic breast cancer, metastatic neuroendocrine tumors, and intrahepatic cholangiocarcinoma. The Company believes that those and similar disease states are areas of unmet medical needs that represent significant market opportunities.

The Company’s investigational new drug application (“IND”) for a Phase 2 clinical trial evaluating HEPZATO in combination with standard of care (“SOC”) for liver-dominant metastatic colorectal cancer was cleared by the FDA in December 2024. The Phase 2 trial will evaluate the safety and efficacy of HEPZATO in combination with trifluridine-tipiracil and bevacizumab compared to trifluridine-tipiracil and bevacizumab alone in patients with liver-dominant mCRC receiving third-line treatment. Approximately 90 patients will be enrolled in this randomized, controlled trial. The study will take place at more than 20 sites across the United States and Europe, with patient enrollment expected to begin in the second half of 2025. In July 2025, the Company received authorization from the European Union and United Kingdom regulatory authorities for the clinical study of Melphalan for Injection/Hepatic Delivery System in patients with refractory metastatic colorectal cancer with liver dominant disease.

On April 28, 2025, the Company announced the clearance by the FDA of its IND application for the Phase 2 clinical trial of HEPZATO in liver-dominant metastatic breast cancer. The Phase 2 trial will evaluate the safety and efficacy of HEPZATO in combination with SOC versus SOC alone in patients with liver-dominant HER2-negative mBC following the failure of previous treatments. The SOC options will be the physician’s choice of eribulin, vinorelbine or capecitabine. We expect approximately 90 patients will be enrolled in this randomized, controlled trial. The trial will take place at more than 20 sites across the United States and Europe, with patient enrollment expected to begin in the fourth quarter of 2025.

Risks and Uncertainties

As detailed in the Company’s 2024 Annual Report filed on Form 10-K, the Company is subject to risks common to companies in the biopharmaceutical industry including, but not limited to, the risks associated with developing product candidates and successfully launching and commercializing its drug/device combination products, the Company’s ability to obtain regulatory approval of its such products in the United States and other geography markets, the uncertainty of the broad adoption of its approved products by physicians and consumers, and significant competition.

In addition, high rates ofinflation have resulted in the United States Federal Reserve raising interest rates. Increases in interest rates, especially if coupled with reduced government spending and volatility in financial markets, may further increase economic uncertainty and heighten these risks. Furthermore, if additional banks and financial institutions enter receivership or become insolvent in the future in response to financial conditions affecting the banking system and financial markets, the Company or its partners’ ability to access existing cash, cash equivalents and investments may be threatened and could have a material adverse effect on the Company’s business and financial condition, including the Company’s ability to access additional capital on favorable terms, or at all, which could in the future negatively affect the Company’s ability to pursue its business strategy.

Factors such as geopolitical events, global health outbreaks, adverse weather events, labor or raw material shortages, imposition of tariffs or trade restrictions and other supply chain disruptions could result in difficulties and delays in manufacturing our products, which could have an adverse impact on our results in operations or result in product shortages, including increasing the cost of ongoing clinical trials. We may also have to take inventory write-offs and incur other charges and expense for products that fail to meet specifications, undertake costly remediation efforts or seek more costly manufacturing alternatives. Such developments could increase our manufacturing costs, cause us to lose revenue or market share as patients and physicians turn to competing therapeutics, diminish our profitability or damage our reputation.

The United States has announced a broad range of tariffs on goods imported into the United States, many of which were then paused. The majority of the Company’s sales are domestic, and while the Company sources certain components outside of the United States, the costs associated with imported materials needed for its operations is a modest portion of our overall manufacturing costs. The Company will continue to monitor the implementation and effect of these and other proposed tariffs.

Liquidity

The accompanying consolidated financial statements have been prepared on a basis which assumes that the Company will continue as a going concern and contemplates the realization of assets and the satisfaction of liabilities and commitments in the normal course of business.

On June 30, 2025, the Company had cash and cash equivalents totaling $34.4 million and short-term investments totaling $46.6 million, as compared to cash and cash equivalents totaling $32.4 million and short-term investments totaling $20.8 million at December 31, 2024. During the six months ended June 30, 2025, cash provided by operating activities was $9.5 million.

The Company believes that the current cash on hand, cash equivalents, investments and net cash provided by operating activities will be sufficient to support current operations through at least 12 months from the issuance of these condensed consolidated financial statements. Actual future liquidity and capital requirements will depend on numerous factors, including the initiation and progress of clinical trials and research and product development programs; obtaining regulatory approvals and complying with applicable laws and regulations; the timing and effectiveness of product commercialization activities, including marketing arrangements; the timing and costs involved in preparing, filing, prosecuting, defending and enforcing intellectual property rights; the resolution of any disputes with third parties; and the effect of competing technological and market developments.

The Company’s capital commitments over the next twelve months include $10.4 million to satisfy accounts payable, accrued expenses, current lease liabilities and current medac settlement. Additional capital commitments beyond the next twelve months include (a) $1.2 million of lease liabilities; and (b) $0.6 million for settlement of litigation with medac. For more information on the medac settlement, see Note 12 -“Commitments and Contingencies - medac Matter”.

Basis of Presentation

These interim condensed consolidated financial statements are unaudited and were prepared by the Company in accordance with generally accepted accounting principles in the United States of America (“GAAP”) and with the SEC’s instructions to Form 10-Q and Article 10 of Regulation S-X. They include the accounts of all wholly owned subsidiaries and all significant inter-company accounts and transactions have been eliminated in consolidation.

The preparation of interim condensed consolidated financial statements requires management to make assumptions and estimates that impact the amounts reported. These interim condensed consolidated financial statements reflect all adjustments, consisting of normal recurring accruals, necessary for a fair presentation of the Company’s results of operations, financial position and cash flows for the interim periods ended June 30, 2025 and 2024; however, certain information and footnote disclosures normally included in our audited consolidated financial statements which were included in the Annual Report have been condensed or omitted as permitted by GAAP. It is important to note that the Company’s results of operations and cash flows for interim periods are not necessarily indicative of the results of operations and cash flows to be expected for a full fiscal year or any interim period.

Significant Accounting Policies

There have been no material changes to our significant accounting policies as set forth in Note 3 Summary of Significant Accounting Policies to the consolidated financial statements included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2024.

Recent Accounting Pronouncements

No new accounting standards were adopted during the six months ended June 30, 2025.

(2)Revenue

The Company recognizes product revenue from sales of HEPZATO in the United States and CHEMOSAT in certain European countries in accordance with the five-step model in Accounting Standards Codification (“ASC”) 606, Revenue Recognition: (i) identify contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenues when (or as) the Company satisfies the performance obligation. Under this revenue standard, the Company recognizes revenue when its customer obtains control of the promised goods, in an amount that reflects the consideration which the Company expects to receive in exchange for those goods.

HEPZATO

The Company ships and sells the HEPZATO KIT directly to hospitals and treating centers based on approved agreements. For certain customers, the inventory is considered on consignment in which the Company retains title to the product until the use of the HEPZATO KIT. For these sales, the Company recognizes HEPZATO revenue, based on contracted or published rates, upon completion of the procedure. There is no obligation for the hospitals or treating centers to use the consigned HEPZATO, and the Company has no contractual right to receive payment until the product is used in a procedure and transfer of control is completed. See Note 4 for further information regarding consignment inventory.

Hospitals and treating centers may also elect to purchase HEPZATO KITS prior to a procedure. For these sales, the purchasing hospital or treatment center obtains control of the product once it is delivered. In these instances, the Company recognizes the HEPZATO KIT revenue based on contracted rates stated in an approved contract or purchase order upon delivery to the customer. There are no contractual rights of returns, refunds or similar obligations.

CHEMOSAT

CHEMOSAT is sold directly to hospitals in the European Union and United Kingdom based on contracted rates in an approved contract or sales order. The Company recognizes product revenue from sales of CHEMOSAT upon shipment.

Revenue by product for the periods indicated were as follows:

Concentration of Credit Risk

Potential credit risk exposure for both the HEPZATO KIT and CHEMOSAT has been evaluated for the Company’s accounts receivable in accordance with ASC 326, Financial Instruments - Credit Losses. The loss percentage is calculated through the use of current and historical economic and financial information. As of June 30, 2025, there were no estimated losses applied to the accounts receivables balance.

The Company’s total percentage of revenue and accounts receivable balances were comprised of the following concentrations from its largest customers, based on whose revenue and/or accounts receivable concentration is greater than 10% of total revenue or total accounts receivable in the periods disclosed below:

On May 22, 2025, Delcath announced a plan to enter into the National Drug Rebate Agreement (“NDRA”) with the Centers for Medicare and Medicaid Services (“CMS”), which also subjected the Company to entering into a Pharmaceutical Pricing Agreement (“PPA”) with the Public Health Service and a master agreement with the U.S. Department of Veterans Affairs (“VA”). Pursuant to the NDRA, the Company must pay mandated rebates to states for Medicaid usage. Under the PPA, beginning on July 1, 2025, the Company began selling HEPZATO to eligible covered entities at the statutory 340B price. The Company is also obligated to make any sales to the VA at the Federal Ceiling Price. The NDRA, the PPA, and the agreement with the VA requires the Company to calculate and submit additional pricing calculations and subject the Company to potential penalties for failing to make timely and/or accurate reports of the required values.

(3)Investments

Marketable debt securities held by the Company are classified as available-for-sale pursuant to ASC 320, Investments - Debt and Equity Securities, and carried at fair value in the accompanying condensed consolidated balance sheets.

The following table summarizes the gross unrealized gains on the Company’s marketable securities as of June 30, 2025:

As of June 30, 2025, there was $0.4 million of interest receivable related to the outstanding debt securities held by the Company.

The following table summarizes the gross unrealized gains on the Company’s marketable securities as of December 31, 2024:

As of December 31, 2024, there was $0.1 million of interest receivable related to the outstanding debt securities held by the Company.

(4)Inventory

Inventory consists of the following:

The Company has consignment agreements with approved hospitals and treatment centers. As of June 30, 2025, there was approximately $0.6 million in finished goods held at hospitals and treatment centers.

(5)Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consist of the following:

(6)Property, Plant, and Equipment

Property, plant, and equipment consist of the following:

Depreciation expense for the three and six months ended June 30, 2025 and 2024 was less than $0.1 million for each period.

(7)Accrued Expenses

Accrued expenses consist of the following:

(8)Leases

The Company recognizes right-of-use (“ROU”) assets and lease liabilities when it obtains the right to control an asset under a leasing arrangement with an initial term greater than twelve months. The Company leases its facilities under non-cancellable operating leases. The Company evaluates the nature of each lease at the inception of an arrangement to determine whether it is an operating or financing lease and recognizes the ROU asset and lease liabilities based on the present value of future minimum lease payments over the expected lease term. The Company’s leases do not generally contain an implicit interest rate and therefore the Company uses the incremental borrowing rate it would expect to pay to borrow on a similar collateralized basis over a similar term in order to determine the present value of its lease payments.

For both the three and six months ended June 30, 2025 and 2024, the Company recognized less than $0.1 million of operating lease expense and less than $0.1 million was recorded for short-term leases.

In 2021, the Company entered into a sub-lease agreement (the “2021 Sub-Lease”) with its previous sub-lessee pursuant to which, effective August 2, 2021, the previous sub-lessee would become the lessee and the Company would then sublease its portion of the premises in Galway, Ireland from the previous sub-lessee. The Company’s annual rent expense under the 2021 Sub-Lease is less than$0.1 million for a term of 5 years.

On January 18, 2024, the Company entered into a lease agreement (the “Queensbury Lease”) to lease approximately 18,000 square feet of manufacturing and office space in Queensbury, New York. The initial term of the lease isfive years with a right to extend the lease by an additional five years, exercisable under certain conditions set forth in the Queensbury Lease. The Company’s annual rent expense under the Queensbury Lease is less than$0.2 million for a term of 5 years.

The following table summarizes the Company’s operating leases as of June 30, 2025:

Remaining maturities of the Company’s operating leases, excluding short-term leases, are as follows:

(9)Stockholders’ Equity

Public and Private Placements

June 2024 Shelf Registration Statement

On June 28, 2024, the Company filed a universal shelf registration statement on Form S-3 (the “June 2024 Shelf Registration Statement”) with the SEC, pursuant to which the Company may offer, issue and sell any combination of shares of the Company’s common stock, par value $0.01 per share, shares of the Company’s preferred stock, par value $0.01 per share, debt securities, warrants to purchase common stock, preferred stock and/or debt securities, in one or more series, and units consisting of any combination of the other types of securities registered under such June 2024 Shelf Registration Statement in an aggregate amount of up to $150 million, in each case, to the public in one or more registered offerings. The June 2024 Shelf Registration Statement was declared effective on August 5, 2024.

Authorized Shares

The Company is authorized to issue 80 million shares of common stock, $0.01 par value, and 10 million shares of preferred stock, $0.01 par value. As of June 30, 2025, the Company has designated the following preferred stock:

Preferred Stock

As of June 30, 2025, there were an aggregate of 10,957 shares of Series E and Series E-1,1,085 Series F-2 and 2,150 Series F-4 Convertible Preferred Stock outstanding, respectively.

Subject to limitations set forth in the Beneficial Ownership Limitation, the shares of Series E and E-1 Preferred Stock are convertible into common stock at the option of the holder at the conversion price of $10.00 per share.

Subject to limitations set forth in the Certificate of Designation, the shares of Series F-2 and F-4 Preferred Stock are convertible into common stock at the option of the holder at the conversion price of $3.30 per share and $6.00 per share, respectively, rounded down to the nearest whole share, and in each case subject to the terms and limitations contained in the Certificate of Designation.

The outstanding Series F-2 and F-4 Preferred Stock are not mandatorily redeemable, redeemable at the holder’s election or contingently redeemable at the holder’s election (at this point, a Deemed Liquidation Event would potentially trigger pro rata liquidation payments to the preferred and common stockholders on a pro rata “as converted” basis). Accordingly, the Series F-2 and F-4 Preferred are classified as permanent equity.

Omnibus Equity Incentive Plan

On September 30, 2020, the Company’s 2020 Omnibus Equity Incentive Plan (the “2020 Plan”) was adopted by the Company’s Board of Directors. On November 23, 2020, the Company’s stockholders approved the 2020 Plan. The 2020 Plan will continue in effect until the tenth anniversary of the date of its adoption by the Board or until earlier terminated by the Board. The 2020 Plan is administered by the Board of Directors or a committee designated by the Board of Directors. The 2020 Plan provides for the grant of incentive stock options, non-qualified stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance awards, as well as other stock-based awards or cash awards that are deemed to be consistent with the purposes of the plan to Company employees, directors and consultants. As of June 30, 2025, there are 9,325,000 shares of common stock reserved under the 2020 Plan, which includes the additional 2,200,000 shares approved by shareholders on May 15, 2025, of which 2,382,636 shares of common stock remained available to be issued under the 2020 Plan.

In addition to options granted from the 2020 Plan, the Company also grants employment inducement awards pursuant to Listing Rule 5635(c)(4) of the corporate governance rules of the Nasdaq Stock Market. The inducement grants are intended to provide incentive to certain individuals to enter into employment with the Company. Prior to December 5, 2023, the inducement awards were granted outside of the 2020 Plan, however they are governed in all respects as if they were issued under the 2020 Plan. These grants do not reduce the number of options available for issuance under the 2020 Plan.

On December 5, 2023, the Company’s 2023 Inducement Plan (the “2023 Plan”) was adopted by the Company’s Board of Directors. The 2023 Plan is administered by a Compensation Committee of two or more Independent Directors appointed by the Board of Directors and is intended to provide for the grant of non-qualified stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance awards, as well as other stock-based awards or cash awards that are deemed appropriate to incentivize employment with the Company. Awards from the 2023 Plan can only be granted to individuals who have not previously worked for the Company or have not worked for the Company for a bona fide period of time. As of June 30, 2025, there have been 1,100,000 shares of common stock reserved under the 2023 Plan, of which 307,131 remain available to be granted.

Stock Options

The following tables include information for all options granted including inducement grants that are granted outside of the 2020 Plan.

The Company values stock options using the Black-Scholes option pricing model and used the following assumptions, on a weighted-average basis, during the reporting periods:

The following is a summary of stock option activity for the six months ended June 30, 2025:

The weighted average grant-date fair value of stock options granted during the six months ended June 30, 2025 and 2024 was $11.82 and $4.09, respectively. The aggregate intrinsic value of stock options exercised was $2.2 million and $0.1 million for the six months ended June 30, 2025 and June 30, 2024, respectively. Total cash received as a result of stock option exercises was $1.5 million and $0.2 million for the six months ended June 30, 2025 and June 30, 2024, respectively.

The following is a summary of share-based compensation expense in the statement of operations:

At June 30, 2025, there was $21.2 million of aggregate unrecognized compensation expense related to employee and board stock option grants. The cost is expected to be recognized over a weighted average period of 1.04 years.

Common Stock Warrants

The following is a summary of common stock warrant activity for the six months ended June 30, 2025:

The following table presents information related to common stock warrants outstanding at June 30, 2025:

(1) Pre-funded warrants with a $0.01 exercise price do not expire until exercised.

Employee Stock Purchase Plan

In August 2021, the Company’s Board of Directors, with shareholder approval in May 2022, adopted the Employee Stock Purchase Plan (the “ESPP”). The ESPP provides for a maximum of 560,295 shares of common stock to be purchased by participating employees, which includes an additional 300,000 shares approved by shareholders on May 15, 2025, of which 148,506 have been issued as of June 30, 2025 since the inception of the benefit in 2021. Employees who elect to participate in the ESPP will be able to purchase common stock at the lower of 85% of the fair market value of common stock on the first or last day of the applicablesix-month offering period.

(10)Net Income (Loss) per Share

Basic net income or loss per share is determined by dividing net loss by the weighted average shares of common stock outstanding during the period, without consideration of potentially dilutive securities, except for those shares that are issuable for little or no cash consideration. Diluted net income or loss per share is determined by dividing net income or loss by diluted weighted average shares outstanding. Diluted weighted average shares reflects the dilutive effect, if any, of potentially dilutive common shares, such as stock options and warrants calculated using the treasury stock method. In periods with reported net operating losses, all common stock options, convertible preferred shares, and preferred and common warrants are generally deemed anti-dilutive such that basic net loss per share and diluted net loss per share are equal.

As of June 30, 2025 and 2024, the Company had 1,341,375 and 737,421 pre-funded warrants outstanding, respectively. The following table provides a reconciliation of the weighted average shares outstanding calculation for the three and six months ended June 30, 2025 and 2024:

The following potentially dilutive securities were excluded from the computation of earnings per share as of June 30, 2025 and 2024 because their effects would be anti-dilutive:

(11)Income Taxes

The Company has recorded a provision for income taxes of $0.7 million for the six months ended June 30, 2025. The Company hadno provision for income taxes for the six months ended June 30, 2024.

As discussed in “Note 16—Income Taxes” to the notes to the consolidated financial statements contained in the Annual Report, the Company has a valuation allowance against the full amount of its net deferred tax assets. The Company currently provides a valuation allowance against deferred tax assets when it is more likely than not that some portion or all of its deferred tax assets will not be realized. The Company has not recognized any unrecognized tax benefits in its balance sheet.

The Company is subject to income tax in the United States, as well as various state and international jurisdictions. The federal and state tax authorities can generally reduce a net operating loss (but not create taxable income) for a period outside the statute of limitations in order to determine the correct amount of net operating loss which may be allowed as a deduction against income for a period within the statute of limitations. Additional information regarding the statutes of limitations can be found in Note 16 - Income Taxes of the Company’s Annual Report.

The Inflation Reduction Act of 2022 included tax legislation that became effective in the first quarter of 2023. Significant legislation for corporate taxpayers includes a corporate alternative minimum tax of 15% for companies with $1 billion or more in average net financial statement profits over the three previous years, as well as a 1% indirect excise tax on the repurchase of shares by a publicly traded company. The Company does not expect this legislation to have an effect on the tax provision as of June 30, 2025, however the Company will continue to evaluate the effect on the tax provision each reporting period.

On July 4, 2025, President Trump signed into law the One Big Beautiful Bill (“OBBB”), which resulted in the extension of many provisions of the current tax law as well as other rule changes that could impact the Company’s tax provision in 2025 or 2026. Examples of the new tax law include the following:

•Full expensing of U.S. research and development costs under Section 174A.

•Retroactive expensing of unamortized U.S. research and development costs capitalized between 2022 and 2024; either all in 2025, or over two years in 2025 and 2026.

•Return of the Section 163(j) taxable income base excluding the deductions for depreciation and amortization in 2025 (change from “Tax EBIT” to “Tax EBITDA”).

•Decrease in the Section 250 deduction for Net CFC Tested Income (formerly GILTI) to 40% (from 50%) in 2026, instead of the scheduled decrease to 37.5% prior to the OBBB.

•Decrease in the Section 250 deduction for foreign-derived income to 33.34% (from 37.5%) in 2026, instead of the scheduled decrease to 21.875% prior to the OBBB.

•Increase in the foreign tax credit rate on Net CFC Tested Income (formerly GILTI) to 90% (from 80%), and a 10% disallowance on repatriation, in 2026.

•Removal of the allocation of interest expense and research and development expense to Net CFC Tested Income (formerly GILTI) in calculating the foreign tax credit limitation, effective in 2026.

The Company is currently evaluating the effect of the OBBB on its future interim and annual financial statements. The Company’s deferred tax asset for U.S. research and development costs may reverse in the subsequent financial statement, decreasing taxes payable by a corresponding amount or increasing other tax attributes for which a valuation allowance is recorded. The full effect of the OBBB is not practical to estimate at this time.

(12)Commitments and Contingencies

medac Matter

In April 2021, the Company’s wholly owned subsidiary, Delcath Systems Ltd, issued to medac GmbH, a privately held, multi-national pharmaceutical company based in Germany (“medac”), an invoice for a €1 million milestone payment under a License, Supply and Marketing Agreement dated December 10, 2018 (the “medac Agreement”) between medac and the Company. The medac Agreement provided to medac the exclusive right to market and sell CHEMOSAT in certain designated countries for which the Company was entitled to a combination of upfront and success-based milestone payments as well as a fixed transfer price per unit of CHEMOSAT and specified royalties.

In response to medac’s subsequent dispute and non-payment of the invoice, on October 12, 2021, the Company notified medac in writing that it was terminating the medac Agreement due to medac’s nonpayment of the €1 million milestone payment, with the effective date of termination of the medac Agreement being April 12, 2022. On December 16, 2021, the Company initiated an arbitration proceeding pursuant to the dispute resolution procedures of the medac Agreement for the non-payment of the invoice.

On December 30, 2022, the parties reached a final settlement of the matter and the Company agreed to pay medac either (a) a royalty on sales of CHEMOSAT units over a defined minimum for a period offive years or until a maximum payment has been reached, or (b) a minimum annual payment of $0.2 million in the event the annual royalty payment does not reach the agreed minimum payment amount. The Company has estimated the remaining fair value of the settlement to be $0.8 million as of June 30, 2025 and recorded $0.6 million as other liabilities, non-current and $0.2 million as accrued expenses on the Company’s condensed consolidated balance sheet as of June 30, 2025.

Manufacturing and Supply Agreements

The Company has a License, Supply and Contract Manufacturing Agreement (as amended, the “Supply Agreement”) with Synerx Pharma, LLC and Mylan Teoranta for the supply of melphalan provided in the HEPZATO KIT. An amendment to the Supply Agreement was entered into on April 22, 2024, and effective as of May 1, 2024, which extends the term of the agreement through December 31, 2028, with an option to renew for successive five-year periods upon the mutual written consent of both parties. Although the Supply Agreement does not contain an annual minimum purchase quantity, the Agreement requires Delcath to order full lots of labeled melphalan vials. The Company received $2.1 million of melphalan under this Supply Agreement in 2025 which is recorded under accounts payable as of June 30, 2025.

Agreements Relating to Clinical Trial Support

The Company has engaged Precision for Medicine LLC (“PfM”) a Clinical Research Organization (“CRO”) to support the Company's Phase 2 clinical trials evaluating HEPZATO in combination with standard of care in patients with liver dominant mCRC and HER2-negative mBC. In addition to the CRO engagement, the Company has also contracted with other vendors, including those relating to data management as well as clinical trial sites as the studies progress. Deposits totaling $2.3 million have been made by the Company in connection with these engagements that are to be applied to future payments due under the service agreements.

(13)Fair Value Measurements

Contingent liabilities are re-measured to fair value each reporting period using projected financial targets, discount rates, probabilities of payment, and projected payment dates. Projected contingent payment amounts are discounted back to the current period using a discounted cash flow model. Projected financial targets are based on our most recent internal operational budgets and may take into consideration alternate scenarios that could result in more or less profitability for the respective service line. Increases or decreases in projected financial targets and probabilities of payment may result in significant changes in the fair value measurements. Increases in discount rates and the time to payment may result in lower fair value measurements. Increases or decreases in any of those inputs in isolation may result in a significantly lower or higher fair value measurement.

The Company’s fair value measurements are classified and disclosed in one of the following three categories:

•Level 1: Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities;

•Level 2: Quoted prices in markets that are not active, or inputs which are observable, either directly or indirectly, for substantially the full term of the asset or liability;

•Level 3: Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (i.e., supported by little or no market activity).

The table below presents activity within Level 3 of the fair value hierarchy, our liabilities carried at fair value relating to the medac settlement, for the six months ended June 30, 2025:

The following tables present information about the Company’s financial assets and liabilities that have been measured at fair value as of June 30, 2025 and December 31, 2024 and indicate the fair value hierarchy of the valuation inputs utilized to determine such fair value.

(14)Segment Information

The Company operates its business primarily in the United States and Europe on a consolidated basis inone reportable segment - the research, development, manufacture and distribution of hepatic delivery systems for the use in the treatment of specific conditions (the “reportable segment”). The Company’s chief operating decision maker (“CODM”) is comprised of a single management team consisting of the Chief Financial Officer, Chief Operating Officer, Chief Medical Officer and General Manager that reports to the Chief Executive Officer. The CODM uses consolidated gross profit and net income or loss, which can be found on the Consolidated Statements of Operations and Comprehensive Loss, to assess financial performance. These financial metrics are used to monitor budget versus actual results. See Note 2 for a description of the Company’s disaggregated revenue by product line. Significant segment expenses reviewed by the CODM are presented in the Company’s Consolidated Statements of Operations and Comprehensive Loss. The measure of segment assets provided to the chief operating decision maker is reported on the balance sheet as total consolidated assets.

(15)Subsequent Events

The Company has evaluated subsequent events for adjustment to or disclosure in these condensed consolidated financial statements through the date of this report and has not identified any recordable or disclosable events not otherwise reported in these financial statements or the notes thereto.