Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations.

The following discussion of our financial condition and results of operations should be read in conjunction with our consolidated financial statements and notes thereto appearing elsewhere in this Annual Report on Form 10-K.

Overview

We are an interventional oncology company focused on the treatment of cancers primary or metastatic to the liver. Our lead product, the HEPZATO KIT (melphalan for Injection/Hepatic Delivery System), a drug/device combination product, was approved by 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

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disease limited to the bone, lymph nodes, subcutaneous tissues, or lung that is amenable to resection, or radiation. The first commercial use of the HEPZATO KIT for the treatment of mUM took place 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 us six 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 and one for doxorubicin in the treatment of patients with hepatocellular carcinoma).

We have sufficient raw material and component constituent parts of the HEPZATO KIT to meet anticipated demand and we intend to manage supply chain risk through stockpiled inventory and 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, or 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 MDR certification under the European Medical Devices Regulation (EU) 2017/745, which may be considered by jurisdictions when evaluating reimbursement. As of March 1, 2022, we have assumed direct responsibility for sales, marketing and distribution of CHEMOSAT in Europe.

The FOCUS Trial

Our clinical development program for HEPZATO was comprised of the FOCUS Trial, a global registration clinical trial that investigated objective response rate in patients with mUM. The current focus of our clinical development program is to generate clinical data for CHEMOSAT and HEPZATO in patients with mUM, either as monotherapy or in combination with immunotherapy. On May 6, 2024, we announced the publication of results from our Phase 3 FOCUS Trial, including an ORR of 36.3%, which included 7.7% of patients with Complete Response, as determined by an Independent Review Committee. An ORR of 36.3% in the FOCUS study was statistically significantly better than the pooled ORR estimate (a weighted mean of the observed ORR) of 5.5% in the historical control group. We expect that the publication will support increased clinical adoption of and reimbursement for CHEMOSAT in Europe, and support reimbursement in various jurisdictions, including the United States.

Our IND application for a Phase 2 clinical trial evaluating HEPZATO in combination with SOC for liver-dominant mCRC 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. Patient enrollment began during the third quarter of 2025, with the study expected to take place at more than 20 sites across the United States and Europe. In July 2025, we 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 the liver dominant disease. The trial’s primary endpoint, hPFS, is anticipated to read out by the end of 2027, while OS, a secondary endpoint, is expected in 2028. We estimate that the total addressable market (“TAM”) for liver-dominant mCRC receiving third-line treatment is between 6,000 and 10,000 patients annually in the United States. This market includes patients who present with significant liver disease burden, with liver-dominant status determined through radiological and clinical criteria. By targeting this patient population, we aim to provide a novel treatment option for those with limited therapeutic alternatives.

On April 28, 2025, we announced our IND application clearance by the FDA for the Phase 2 clinical trial of HEPZATO in mBC. 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 study will take place at more than 15 sites across the United States and Europe, with patient enrollment expected to begin in the first quarter of 2026. The trial’s primary endpoint, hPFS, is anticipated to read out by the end of 2028, while results for OS, a secondary endpoint, is expected in 2029.

We estimate that approximately 7,000 patients annually in the United States are affected by HER2-negative metastatic breast cancer with liver metastases and are candidates for third line treatment. This population includes patients with a significant burden of liver metastases, which are likely to be the primary cause of mortality. By focusing on this demographic, we intend to offer a novel therapeutic option to those patients with limited treatment alternatives.

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We believe that these and similar disease states are areas of unmet medical needs that represent significant market opportunities.

We expense research and development costs as they are incurred. We expect our research and development expenses to increase for the foreseeable future relating to the costs required to complete these Phase 2 clinical trials.

Our expected research and development expenses will consist primarily of:

•salaries and related overhead expenses for personnel in research and development functions, including stock-based compensation;

•fees paid to trial sites, consultants, and the CRO for the clinical trials, along with other related clinical trial fees, including, but not limited to, clinical trial database management, clinical trial material management and statistical compilation and analysis; and

•costs related to compliance with regulatory requirements.

At this time, we cannot reasonably estimate or know the exact nature, timing and estimated costs of the efforts that will be necessary. Non-refundable advance payments that are made for future research and development activities are recorded as prepaid expenses. The prepaid amounts are expensed as the services are performed, or when it is no longer expected that the services will be rendered.

The CHOPIN Trial

On October 18, 2025, independent investigators presented results from the Phase 2 CHOPIN clinical trial. The randomized Phase 2 trial was designed to compare the safety, tolerability, and efficacy of CHEMOSAT with melphalan for PHP when used alone versus when combined with the systemic ICIs ipilimumab and nivolumab. Ipilimumab and nivolumab are approved by the FDA and European Union for the treatment of unresectable metastatic melanoma. The CHOPIN trial included 76 patients randomized 1:1 to receive two PHP treatments alone at weeks one and seven (PHP group) or four cycles of ICI every three weeks over approximately nine weeks with two PHP treatments at weeks one and seven (combination group). The primary study endpoint of one-year progression-free survival rate was met with 54.7% in the combination group versus 15.8% in the PHP group. The secondary endpoints included Safety, OS, PFS and ORR. The combination group saw an increase in median OS of 23.1 months versus 19.6 months (HR = 0.39; p = 0.006), median PFS 12.8 months versus 8.3 months (HR = 0.34; p<0.001) and ORR of 76.3% in the combination group versus 39.5% (p<0.001). Grade 3 or higher treatment-related adverse events were more frequent in the combination group (81.6% versus 40.5%, P<0.001), but most were manageable with standard care. The combination treatment adverse events were consistent with the types, rates, and frequencies of adverse events in PHP and checkpoint inhibitors. No new safety signals were identified.

Liquidity and Capital Resources

Cash Flows

The following table summarizes our sources and uses of cash for each of the periods presented:

Years Ended December 31,

Net cash provided by (used in) operating activities 22,516 (18,681)

Net cash used in investing activities (26,590) (981)

Net cash provided by financing activities 15,048 39,410

Foreign currency effects on cash 68 (32)

On December 31, 2025, we had cash and cash equivalents totaling $43.5 million and short-term investments totaling $47.6 million, as compared to cash and cash equivalents totaling $32.4 million and short-term investments totaling $20.8 million on December 31, 2024.

We believe that our current cash on hand, cash equivalents and investments will be sufficient to support our current operations through at least 12 months from the issuance of the consolidated financial statements included in this Annual

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Report on Form 10-K. Our 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.

Share Repurchase Program

On November 19, 2025, our board of directors authorized a share repurchase program under which we may repurchase up to $25 million of our outstanding shares of common stock, from time to time, through open market transactions, privately negotiated transactions or in such other manners approved by the board of directors. The repurchase program does not obligate us to purchase any shares and does not have an expiration date.

As of December 31, 2025, there have been 628,572 shares of common stock repurchased and retired under the repurchase program at an average price paid per share of $9.5254 for a total aggregate purchase price of approximately $6.0 million. We have approximately $19.0 million remaining under the stock repurchase authorization at December 31, 2025.

Capital Commitments

Our capital commitments over the next twelve months include $11.0 million to satisfy accounts payable, accrued expenses, current lease liabilities and current medac settlement. Additional capital commitments beyond the next twelve months include (a) $0.7 million for settlement of litigation with medac and (b) $1.1 million of lease liabilities.

Sources of Liquidity

June 2024 Shelf Registration Statement

On June 28, 2024, we filed a universal shelf registration statement on Form S-3 (the “June 2024 Shelf Registration Statement”) with the SEC, pursuant to which we may offer, issue and sell any combination of shares of our common stock, par value $0.01 per share, shares of our 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.

Series F Warrants

In May 2020, we completed an underwritten public offering consisting of shares of common stock, Series F warrants to purchase shares of common stock and, to certain investors, in lieu of shares of common stock, pre-funded warrants to purchase shares of common stock. The Series F Warrants had an exercise price of $10.00 per share of common stock and expired on May 5, 2025, while the pre-funded warrants issued in such offering have an exercise price of $0.01, if exercised via cash payment. 1,615,775 Series F Warrants were exercised during the year ended December 31, 2025.

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Results of Operations

Year ended December 31,

Selling, general and administrative expenses 43,528 29,553

Interest and other income (expense) 2,850 (13,976)

Income tax expense 810 —

Revenue

The increase in total revenue for the year ended December 31, 2025 compared to the same period for 2024 was due to the continued commercial expansion and demand of HEPZATO in the United States and CHEMOSAT in Europe. During the year ended December 31, 2025, 24 sites had treated at least one patient in HEPZATO versus 14 sites in the year ended December 31, 2024.

On October 23, 2025, the Company entered into a National Drug Rebate Agreement (“NDRA”) with 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. See Note 4, Revenue, in the accompanying notes to the consolidated financial statements for further details.

Cost of Goods Sold

During the year ended December 31, 2025, we recorded $11.8 million in cost of goods sold. Cost of goods sold increased $5.6 million over the same period in 2024. This increase is directly related to the increase in demand for product revenue which requires an increase in personnel and those associated costs.

Research and Development Expenses

Research and development expenses are incurred for the development of HEPZATO and consist primarily of payroll and payments to contract research and development companies. The increase for the year ended December 31, 2025 compared to the same period in 2024 is due to costs associated with expanding the clinical team including share-based compensation expense related to an increase in headcount and initiation of the Phase 2 clinical trial evaluating HEPZATO in combination with standard of care for mCRC and mBC. In 2024, these costs primarily related to medical affairs and regulatory costs associated with the approved products.

Selling, General and Administrative Expenses

Selling, general and administrative expenses consist primarily of payroll and professional services such as accounting, legal, marketing and commercial preparation services. For the year ended December 31, 2025 compared to the same period in 2024, selling, general and administrative expenses increased due to continued commercial expansion activities including marketing-related travel expenses and additional personnel on the commercial team. In addition, the increase in personnel along with higher grant date exercise prices has increased the share-based compensation expense.

Interest and other Income/Expense

Interest and other income in 2025 are primarily related to the interest income associated with marketable securities and cash on hand. In 2024, this amount was offset by interest expense related to our debt instruments and the change in fair value of warrant liability. There was no interest expense for the year ended December 31, 2025 due to all debt being paid

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off in 2024. There was no change in warrant valuation during the year ended December 31, 2025 due to the exercise of all Tranche B Warrants in 2024.

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Critical Accounting Estimates

Our consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”). Certain critical accounting estimates have a significant impact on amounts reported in the consolidated financial statements. A summary of those critical accounting estimates is below. Additional details surrounding Significant Accounting Policies can be found in Note 3 to our consolidated financial statements contained in this Annual Report on Form 10-K.

Fair Value Measurements

GAAP emphasizes that fair value is a market-based measurement, not an entity-specific measurement. Therefore, a fair value measurement should be determined based on the assumptions that market participants would use in pricing the asset or liability. As a basis for considering market participant assumptions in fair value measurements, GAAP establishes a fair value hierarchy that distinguishes between market participant assumptions based on market data obtained from sources independent of the reporting entity (observable inputs that are classified within Levels 1 and 2 of the hierarchy) and the reporting entity’s own assumptions about market participant assumptions (unobservable inputs classified within Level 3 of the hierarchy).

Our fair value measurements are generally related to a contingent liability, warrant liability, investments, and stock-based compensation.

Contingent Liabilities

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 or decreases in discount rates and the time to payment may result in lower or higher fair value measurements. Increases or decreases in any of those inputs in isolation may result in a significantly lower or higher fair value measurement.

Stock Based Compensation

Valuation of stock options generally requires certain assumptions, including the fair market value of our common stock (generally an observable market price, as our common stock is publicly traded), the expected term of the financial instrument (judgment is required), the expected volatility of our common stock over the expected term (generally estimated by reference to the historical volatility of our common stock), our expected dividend rate over the expected term (currently estimated as zero) and the expected risk-free rate over the expected term (generally estimated by reference to United States treasury instruments with similar remaining terms).

Tax Valuation Allowance

A valuation allowance is recorded if it is more likely than not that a deferred tax asset will not be realized based on the weight of available evidence, both positive and negative. Due to our cumulative loss position and history of operating losses, a full valuation allowance against our net deferred tax assets was considered necessary. We will continue to monitor our cumulative loss position and forecasts and reevaluate the need for a valuation allowance as it could be reversed in future periods.

Accrued Expenses

We utilize CROs in order to perform research and development and conduct clinical trials. In some cases, these organizations do not bill on a timely basis. Management monitors certain key drivers of these costs and estimates accruals in an attempt to properly match expenses incurred with the appropriate reporting period. However, there is judgment involved and the actual billings could be more or less than the estimated accrual.

Item 7A. Quantitative and Qualitative Disclosures About Market Risk

Not required.

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Item 8. Financial Statements and Supplementary Data

Consolidated Balance Sheets F-3

Consolidated Statements of Operations and Comprehensive Income (Loss) F-4

Consolidated Statements of Stockholders’ Equity F-5

Consolidated Statements of Cash Flows F-7

Notes to Consolidated Financial Statements F-8

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REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

To the Stockholders and Board of Directors of

Delcath Systems, Inc.

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheet of Delcath Systems Inc. (the “Company”) as ofDecember 31, 2025, the related consolidated statement of operations and comprehensive income, stockholders’ equity and cash flows for the year ended December 31, 2025, and the related notes (collectively referred to as the “financial statements”). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company as of as of December 31, 2025, and the results of its operations and its cash flows for the year ended December 31, 2025, in conformity with accounting principles generally accepted in the United States of America.

Basis for Opinion

These financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on the Company’s financial statements based on our audit. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (“PCAOB”) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audit in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. The Company is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audit we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Company’s internal control over financial reporting. Accordingly, we express no such opinion.

Our audit included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audit also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audit provides a reasonable basis for our opinion.

Critical Audit Matters

Critical audit matters are matters arising from the current period audit of the financial statements that were communicated or required to be communicated to the audit committee and that: (1) relate to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective, or complex judgments. We determined that there are no critical audit matters.

/s/ CBIZ CPAs P.C.

CBIZ CPAs P.C.

We have served as the Company’s auditor since 2018 (such date takes into account the acquisition of the attest business of Marcum LLP by CBIZ CPAs P.C. effective November 1, 2024).

New York, NY

February 26, 2026

F-1

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REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

To the Stockholders and Board of Directors of

Delcath Systems, Inc.

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheet of Delcath Systems Inc. (the “Company”) as of December 31 2024, the related consolidated statement of operations and comprehensive loss, stockholders’ equity and cash flows for the year ended December 31, 2024, and the related notes (collectively referred to as the “financial statements”). In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2024, and the results of its operations and its cash flows for the year ended December 31, 2024, in conformity with accounting principles generally accepted in the United States of America.

Basis for Opinion

We conducted our audit in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. The Company is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audit we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Company's internal control over financial reporting. Accordingly, we express no such opinion.

Critical Audit Matters

/s/ Marcum LLP

Marcum LLP

We have served as the Company’s auditor from 2018 through March 18, 2025.

New York, NY

March 6, 2025

F-2

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DELCATH SYSTEMS, INC.

Consolidated Balance Sheets

(in thousands, except share and per share data)

Assets

Current assets

Prepaid expenses and other current assets 6,498 2,704

Property, plant and equipment, net 3,166 1,790

Liabilities and Stockholders’ Equity

Current liabilities

Lease liabilities, current 101 105

Lease liabilities, non-current 835 933

Other liabilities, non-current 628 766

Commitments and contingencies (see Note 13)

Stockholders’ equity

Accumulated other comprehensive income 575 82

Total liabilities and stockholders’ equity $ 123,632 $ 76,589

See Accompanying Notes to these Consolidated Financial Statements.

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DELCATH SYSTEMS, INC.

Consolidated Statements of Operations and Comprehensive Income (Loss)

(in thousands, except share and per share data)

Year ended December 31,

Operating expenses:

Selling, general and administrative expenses 43,528 29,553

Change in fair value of warrant liability — (14,071)

Other expense (70) (30)

Income (loss) before income taxes 3,510 (26,386)

Income tax expense 810 —

Other comprehensive income (loss):

Unrealized gain on investments adjustments 394 (22)

Foreign currency translation adjustments 99 (31)

Total comprehensive income (loss) $ 3,193 $ (26,439)

Common share data:

Basic income (loss) per common share $ 0.08 $ (0.93)

Diluted income (loss) per common share $ 0.07 $ (0.93)

See Accompanying Notes to these Consolidated Financial Statements.

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DELCATH SYSTEMS, INC.

Consolidated Statements of Stockholders’ Equity

(in thousands, except share and per share data)

Preferred Stock$0.01 Par Value Common Stock$0.01 Par Value

Compensation expense for issuance of stock options — — — — 23,971 — — 23,971

Compensation expense for Employee Stock Purchase Plan — — — — 261 — — 261

Repurchase and retirement of common stock — — (628,572) (6) (5,994) — — (6,000)

Unrealized gain on investment adjustments — — — — — — 394 394

Foreign currency translation adjustments — — — — — — 99 99

See Accompanying Notes to these Consolidated Financial Statements.

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DELCATH SYSTEMS, INC

Consolidated Statements of Stockholders’ Equity, Continued

(in thousands, except share and per share data)

Preferred Stock$0.01 Par Value Common Stock$0.01 Par Value

Compensation expense for issuance of stock options — — — — 9,571 — — 9,571

Unrealized gain on investments adjustments — — — — — — (22) (22)

Foreign currency translation adjustments — — — — — — (31) (31)

See Accompanying Notes to these Consolidated Financial Statements.

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DELCATH SYSTEMS, INC.

Consolidated Statements of Cash Flows

(in thousands, except share and per share data)

Years Ended December 31,

Cash flows from operating activities:

Stock option compensation expense 24,232 9,767

Warrant liability fair value adjustment — 14,071

Amortization of Right-of-Use Asset 111 95

Amortization of debt discount — 460

Interest expense accrued related to convertible notes — 133

Interest paid related to convertible notes — (847)

Amortization of premiums and discounts on marketable securities (1,696) (587)

Changes in operating assets and liabilities:

Prepaid expenses and other assets (3,421) (1,639)

Accounts payable and accrued expenses 4,766 479

Other liabilities, non-current (241) (101)

Net cash provided by (used in) operating activities 22,516 (18,681)

Cash flows from investing activities:

Purchase of property, plant and equipment (1,547) (559)

Net cash used in investing activities (26,590) (981)

Cash flows from financing activities:

Net proceeds from private placement — 6,771

Repayment of Debt — (10,610)

Proceeds from the exercise of warrants 16,158 41,317

Proceeds from the exercise of stock options 4,409 1,682

Repurchase and retirement of common stock (6,000) —

Net cash provided by financing activities 15,048 39,410

Foreign currency effects on cash 68 (32)

Total Cash and Cash Equivalents:

Years Ended December 31,

Supplemental Disclosure of Cash Flow Information:

Cash paid during the periods for:

Interest paid $ — $ 1,236

Taxes paid $ 1,545 $ —

Supplemental Disclosure of Non-Cash Investing and Financing Activities:

Right of use assets obtained in exchange for lease obligations $ — $ 1,029

See Accompanying Notes to these Consolidated Financial Statements.

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DELCATH SYSTEMS, INC.

Notes to Consolidated Financial Statements

for the Years Ended December 31, 2025 and 2024

(1) Description of Business

Delcath Systems, Inc. (“Delcath” or “the Company”) is an interventional oncology company focused on the treatment of cancers primary or metastatic 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 the 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 Delcath six 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 and one 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 for two years in the Vastra Gotaland Region in Sweden.

On October 18, 2025, the Company announced the results of the investigator-initiated CHOPIN clinical trial. The randomized Phase 2 trial was designed to compare the safety, tolerability, and efficacy of CHEMOSAT with melphalan for percutaneous hepatic perfusion (PHP) when used alone versus when combined with the systemic immune checkpoint inhibitors (ICI) ipilimumab and nivolumab. Ipilimumab and nivolumab are approved by the FDA and European Union for the treatment of unresectable metastatic melanoma. The CHOPIN trial included 76 patients randomized 1:1 to receive two PHP treatments alone at weeks one and seven (PHP group) or four cycles of ICI every three weeks over approximately nine weeks with two PHP treatments at weeks one and seven (combination group). The primary study endpoint of one-year progression-free survival rate was met with 54.7% in the combination group versus 15.8% in the PHP group. The secondary endpoints included Safety, Overall Survival (“OS”), Progression Free Survival (“PFS”) and Overall Response Rate (“ORR”). The combination group saw an increase in median OS of 23.1 months versus 19.6 months (HR = 0.39; p = 0.006), median PFS 12.8 months versus 8.3 months (HR = 0.34; p<0.001) and ORR of 76.3% in the combination group versus 39.5% (p<0.001). Grade 3 or higher treatment-related adverse events were more frequent in the combination group (81.6% versus 40.5%, P<0.001), but most were manageable with standard care. Overall, the combination treatment was well tolerated, with types, rates and frequencies of adverse events consistent with individual use of PHP and checkpoint inhibitors. No new safety signals were identified.

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

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DELCATH SYSTEMS, INC.

Notes to Consolidated Financial Statements

for the Years Ended December 31, 2025 and 2024

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. Patient enrollment began during the third quarter of 2025, with the study expected to take place at more than 20 sites across the United States and Europe. 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 15 sites across the United States and Europe, with patient enrollment expected to begin in the first quarter of 2026.

Risks and Uncertainties

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.

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.

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DELCATH SYSTEMS, INC.

Notes to Consolidated Financial Statements

for the Years Ended December 31, 2025 and 2024

On December 31, 2025, the Company had cash and cash equivalents totaling $43.5 million and short-term investments totaling $47.6 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.

(2) Basis of Consolidated Financial Statement Presentation

The accounting and financial reporting policies of the Company conform to generally accepted accounting principles in the United States of America (“GAAP”). The preparation of consolidated financial statements in conformity with GAAP requires management to make assumptions and estimates that impact the amounts reported in the Company’s consolidated financial statements. The consolidated financial statements include the accounts of all entities controlled by the Company. All significant inter-company accounts and transactions are eliminated.

(3) Summary of Significant Accounting Policies

Use of Estimates

The Company bases its estimates and judgments on historical experience and on various other assumptions that it believes are reasonable under the circumstances. The amounts of assets and liabilities reported in the Company’s consolidated balance sheets and the amount of revenues and expenses reported for each of the periods presented are affected by estimates and assumptions, which are used for, but not limited to, the accounting for valuation of warrants, stock-based compensation, valuation of inventory, impairment of long-lived assets, income taxes and operating expense accruals. Such assumptions and estimates are subject to change in the future as additional information becomes available or as circumstances are modified. Actual results could differ from these estimates.

Cash Equivalents and Concentrations of Credit Risk

The Company considers investments with original maturities of three months or less at date of acquisition to be cash equivalents. The Company has deposits that exceed amounts insured by the Federal Deposit Insurance Corporation; however, the Company does not consider this a significant concentration of credit risk based on the strength of the financial institution.

Investments

Investments classified as short-term have maturities of less than one year. Investments classified as long-term are those that: (i) have a maturity of greater than one year, and (ii) the Company does not intend to liquidate within the next twelve months, although these funds are available for use and, therefore, are classified as available-for-sale. The Company’s investment strategy is to buy short-duration Treasury bills (T-bills). At December 31, 2025, all investments held by the Company had remaining contractual maturities of less than six months.

Accounts Receivable

Accounts receivable, principally trade, are generally due within 30 to 60 days and are stated at amounts due from customers. Collections and payments from customers are monitored and a provision for estimated credit losses may be created based upon historical experience and specific customer collection issues that may be identified.

The following table shows the opening and closing balances for the years ended:

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DELCATH SYSTEMS, INC.

Notes to Consolidated Financial Statements

for the Years Ended December 31, 2025 and 2024

Inventories

Inventories are valued at the lower of cost or net realizable value (“NRV”) using the first-in, first-out method. The reported “NRV” of inventory includes finished saleable products, work-in-process, and raw materials that will be sold or used in future periods. The Company reserves for expired, obsolete, and slow-moving inventory.

Property, Plant and Equipment

Property, plant, and equipment are recorded at cost, less accumulated depreciation. The Company provides for depreciation on a straight-line basis over the estimated useful lives of the assets which range from three to seven years. Leasehold improvements will be amortized over the shorter of the lease term or the estimated useful life of the related assets when they are placed into service. The Company evaluates property, plant and equipment for impairment periodically to determine if changes in circumstances or the occurrence of events suggest the carrying value of the asset or asset group may not be recoverable. Maintenance and repairs are charged to operations as incurred. Expenditures which substantially increase the useful lives of the related assets are capitalized.

Leases

The Company determines if an arrangement is a lease at inception, in accordance with Accounting Standards Codification (“ASC”) Topic 842, Leases. All operating lease commitments with a lease term greater than 12 months are recognized as right-of-use assets and lease liabilities, on a discounted basis on the balance sheet. Leases with an initial term of 12 months or less are not recorded on the balance sheet. Certain of the Company’s lease agreements include lease payments that are adjusted periodically for an index or rate. The leases are initially measured using the present value of the projected payments adjusted for the index or rate in effect at the commencement date. In addition to rent, the leases may require the Company to pay additional amounts for taxes, insurance, maintenance and other expenses, which do not transfer a good or service to the Company and are generally referred to as non-lease components. Variable non-lease components are not measured as part of the right-of-use asset and liability. Only when lease components and their associated non-lease components are fixed are they accounted for as a single lease component and are recognized as part of a right-of-use asset and liability. The Company’s lease agreements do not contain any material residual value guarantees or material restrictive covenants.

The Company may have options to renew lease terms for facilities and other assets. Some leases contain clauses for renewal at the Company’s option with renewal terms that generally extend the lease term from 1 to 5 years. The exercise of lease renewal options is generally at the Company’s sole discretion. The Company evaluates renewal and termination options at the lease commencement date to determine if it is reasonably certain to exercise the option on the basis of economic factors.

Fair Value Measurements

The Company adheres to ASC 820, Fair Value Measurement, which defines fair value, establishes a framework for measuring fair value, and expands disclosures about fair value measurements. ASC 820 applies to reported balances that are required or permitted to be measured at fair value under existing accounting pronouncements; accordingly, the standard does not require any new fair value measurements of reported balances.

ASC 820 emphasizes that fair value is a market-based measurement, not an entity-specific measurement. Therefore, a fair value measurement should be determined based on the assumptions that market participants would use in pricing the asset or liability. As a basis for considering market participant assumptions in fair value measurements, ASC 820 establishes a fair value hierarchy that distinguishes between market participant assumptions based on market data obtained from sources independent of the reporting entity (observable inputs that are classified within

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DELCATH SYSTEMS, INC.

Notes to Consolidated Financial Statements

for the Years Ended December 31, 2025 and 2024

Levels 1 and 2 of the hierarchy) and the reporting entity’s own assumptions about market participant assumptions (unobservable inputs classified within Level 3 of the hierarchy).

•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).

In instances where the determination of the fair value measurement is based on inputs from different levels of the fair value hierarchy, the level in the fair value hierarchy within which the entire fair value measurement falls is based on the lowest level input that is significant to the fair value measurement in its entirety. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability.

Revenue Recognition

Revenue is generated from proprietary and partnered product sales. Revenue is recognized when or as the Company transfers control of the promised goods to its customers in an amount that reflects the consideration to which the Company expects to be entitled to in exchange for those goods.

The Company does not currently have any but may enter into contracts with partners that contain multiple elements such as licensing, development, manufacturing, and commercialization components. These arrangements are often complex, and the Company may receive various types of consideration over the life of the arrangement, including up-front fees, reimbursements for research and development services, milestone payments, payments on product shipments, margin sharing arrangements, license fees and royalties.

The Company recognizes revenue in accordance with ASC 606, Revenue from Contracts with Customers. The core principle of ASC 606 requires that an entity recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASC 606 defines a five-step process to achieve this core principle and, in doing so, it is possible more judgment and estimates may be required within the revenue recognition process, including identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation.

The following five steps are applied to achieve that core principle:

•Step 1: Identify the contract with the customer;

•Step 2: Identify the performance obligations in the contract;

•Step 3: Determine the transaction price, including an estimation of any variable consideration expected to be received in connection with the contract;

•Step 4: Allocate the transaction price to the performance obligations in the contract; and

•Step 5: Recognize revenue when the company satisfies a performance obligation.

Each of these steps in the revenue recognition process requires management to make judgments and/or estimates. The most significant judgments and estimates involve the determination of variable consideration to be included in the transaction price, including rebates that may be due under the Medicaid Drug Rebate Agreement. Management believes this provides a reasonable basis for recognizing revenue; however, actual results could differ from estimates and significant changes in estimates could impact the Company’s results of operations in future periods.

As required by ASC 606, the Company disaggregates its revenue into the categories of product revenue and other revenue. In 2025, the Company recognized only product revenue. See Note 4, Revenue, in the accompanying notes to the consolidated financial statements for further detail.

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DELCATH SYSTEMS, INC.

Notes to Consolidated Financial Statements

for the Years Ended December 31, 2025 and 2024

Selling, General and Administrative

Selling, general and administrative costs include personnel costs and related expenses for the Company’s sales, marketing, general management and administrative staff, recruitment, costs related to the Company’s commercialization efforts, professional service fees, professional license fees, business development and certain general legal activities. All such costs are charged to expense when incurred.

Research and Development

Research and development costs include the costs of materials used for clinical trials, personnel costs associated with device and pharmaceutical development expenses, clinical affairs, medical affairs, medical science liaisons, and regulatory affairs, costs of outside services and applicable indirect costs incurred in the development of the Company’s proprietary drug delivery system. All such costs are charged to expense when incurred.

Stock Based Compensation

The Company accounts for its share-based compensation in accordance with the provisions of ASC 718, Stock-Based Compensation, which establishes accounting for equity instruments exchanged for services. Under the provisions of ASC 718, share-based compensation is measured at the grant date, based upon the fair value of the award, and is recognized as an expense over the option holders’ requisite service period, which is generally three years for grants to employees and one year for grants to non-employee directors and is generally also the vesting period of the equity grant. The Company accounts for forfeitures as they occur. The Company expenses its share-based compensation granted under the accelerated method, which treats each vesting tranche as if it were an individual grant.

The Company periodically grants stock options for a fixed number of shares of common stock to its employees, directors, and non-employee contractors. The exercise price is greater than or equal to the fair market value of the common stock at the date of the grant and the Company estimates the fair value of stock options using the Black-Scholes option pricing model. Key inputs used to estimate the fair value of stock options include the exercise price of the option, the expected term, the expected volatility of the stock over the option’s expected term, the risk-free interest rate over the option’s expected term, and the expected annual dividend yield. Estimates of fair value are not intended to predict actual future events or the value ultimately realized by persons who receive equity awards.

Income Taxes

The Company accounts for income taxes following the asset and liability method in accordance with the ASC 740 “Income Taxes.” Under such method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the consolidated financial statement carrying amounts of existing assets and liabilities and their respective tax bases. The Company applies the accounting guidance issued to address the accounting for uncertain tax positions. This guidance clarifies the accounting for income taxes, by prescribing a minimum recognition threshold a tax position is required to meet before being recognized in the financial statements as well as provides guidance on derecognition, measurement, classification, interest and penalties, accounting in interim periods, disclosure, and transition. The Company classifies interest and penalty expense related to uncertain tax positions as a component of income tax expense. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years that the asset is expected to be recovered or the liability settled. A valuation allowance is provided when it is more likely than not that some portion or all of a deferred tax asset will not be realized. The ultimate realization of deferred tax assets depends on the generation of future taxable income during the period in which related temporary differences become deductible. The Company considers the scheduled reversal of deferred tax liabilities, projected future taxable income and tax planning strategies in its assessment of a valuation allowance. See Note 14 - Income Taxes for additional information.

Foreign Currency and Currency Translation

Transactions that are denominated in a foreign currency are remeasured into the functional currency at the current exchange rate on the date of the transaction. Any foreign currency-denominated monetary assets and liabilities are

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DELCATH SYSTEMS, INC.

Notes to Consolidated Financial Statements

for the Years Ended December 31, 2025 and 2024

subsequently remeasured at current exchange rates, with gains or losses recognized as foreign exchange (losses)/gains in the statements of operations.

The assets and liabilities of the Company’s international subsidiaries are translated from their functional currencies into United States dollars at exchange rates prevailing at the balance sheet date. The majority of the foreign subsidiaries revenues and operating expenses are denominated in Euros. The reporting currency for the Company is the United States dollar. Average rates of exchange during the period are used to translate the statement of operations, while historical rates of exchange are used to translate any equity transactions.

Translation adjustments arising on consolidation due to differences between average rates and balance sheet rates, as well as unrealized foreign exchange gains or losses arising from translation of intercompany loans that are of a long-term-investment nature, are recorded in other comprehensive income.

Subsequent Events

Management has evaluated events occurring subsequent to the consolidated balance sheet date, through February 26, 2026, which is the date the consolidated financial statements were issued, determining all subsequent events have been disclosed.

Recently Issued Accounting Pronouncements

ASU 2024-03, Disaggregation of Income Statement Expenses

In November 2024, the Financial Accounting Standards Board (“FASB”) issued ASU 2024-03, Income Statement - Reporting Comprehensive Income (Topic 220): Expense Disaggregation Disclosures to improve the disclosures about a public entity’s expenses and provide more detailed information about the types of expenses in commonly presented expense captions such as inventory purchases, employee compensation, depreciation and intangible asset amortization. The disclosure requirements must be applied retrospectively to all prior periods presented in the financial statements. The effective date for the standard is for fiscal years beginning after December 15, 2026 and interim periods within fiscal years beginning after December 15, 2027, with early adoption permitted. The Company is currently evaluating the effects adoption of this guidance will have on the consolidated financial statements.

Recently Adopted Accounting Pronouncements

ASU 2023-09, Improvements to Income Tax Disclosures

On December 14, 2023, the FASB issued, ASU 2023-09, Improvements to Income Tax Disclosures, a final standard on improvements to income tax disclosures. The standard requires disaggregated information about a reporting entity’s effective tax rate reconciliation as well as information on income taxes paid. The standard applies to all entities subject to income taxes and is intended to benefit investors by providing more detailed income tax disclosures that would be useful in making capital allocation decisions. For public business entities (PBEs), the new requirements are effective for annual periods beginning after December 15, 2024. The guidance is applied on a prospective basis with the option to apply the standard retrospectively. The Company adopted ASU 2023-09 on a prospective basis beginning with the year ended December 31, 2025. See Note 14 - Income Taxes in the accompanying notes to the consolidated financial statements for further detail.

(4) 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.

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DELCATH SYSTEMS, INC.

Notes to Consolidated Financial Statements

for the Years Ended December 31, 2025 and 2024

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

Payment terms, returns, and warranties

The Company’s revenue arrangements do not contain significant financing components as payment terms are generally 30 to 60 days. HEPZATO and CHEMOSAT have no contractual rights of returns, refunds or similar obligations beyond assurance-type quality warranties. HEPZATO or CHEMOSAT kits that are deemed defective are replaced at no cost to the hospital or treating center.

The Company does not have any contract assets or contract liabilities at December 31, 2025 or 2024 because the contracts generally do not include performance obligations satisfied over time or advance customer consideration.

HEPZATO

The Company ships and sells HEPZATO 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. 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 6 - Inventories for further information regarding consignment inventory.

Hospitals and treating centers may also elect to purchase HEPZATO 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 revenue based on contracted rates stated in an approved contract or purchase order upon delivery to the customer.

On May 22, 2025, the Company announced a plan to enter into a 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. The rebates are variable consideration and must be estimated at each reporting period and are treated as a reduction of revenue in the same period the related revenue is recognized. These estimates are based on historical experience and payer mix and will be adjusted as actual claims are processed. At December 31, 2025, there were no accrued rebates included in the Company’s financials.

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. Due to the Company selling directly to the hospital or treating center, the purchase price of either wholesale acquisition cost or 340B is known at the time of revenue recognition. No chargeback estimate is recorded on the consolidated balance sheets.

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.

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:

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DELCATH SYSTEMS, INC.

Notes to Consolidated Financial Statements

for the Years Ended December 31, 2025 and 2024

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

Twelve Months Ended December 31,

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 December 31, 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 or accounts receivable concentration is greater than 10% of total revenue or total accounts receivable in the periods disclosed below.

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DELCATH SYSTEMS, INC.

Notes to Consolidated Financial Statements

for the Years Ended December 31, 2025 and 2024

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

(5) 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 consolidated balance sheets.

The following table summarizes the gross unrealized gains on the Company’s marketable securities as of December 31, 2025:

Gross Unrealized

(In thousands) Amortized Cost Gains Estimated Fair Value

Classified as:

Short-term investments $ 47,582

As of December 31, 2025, there was $0.5 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:

Gross Unrealized

(In thousands) Amortized Cost Gains Estimated Fair Value

Classified as:

Short-term investments $ 20,821

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

(6) Inventory

Inventory consists of the following:

The Company has consignment agreements with approved hospitals and treatment centers. As of December 31, 2025, there was approximately $0.6 million in finished goods held at hospitals and treatment centers.

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DELCATH SYSTEMS, INC.

Notes to Consolidated Financial Statements

for the Years Ended December 31, 2025 and 2024

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

(7) Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets include the following:

Clinical trial expenses $ 2,405 $ 222

Total prepaid expenses and other current assets $ 6,498 $ 2,704

(8) Property, Plant, and Equipment

Property, plant, and equipment consists of:

(In thousands) December 31, 2025 December 31, 2024 Estimated Useful Life

Enterprise hardware and software 1,819 1,811 3 years

Leaseholds 1,648 1,585 Lesser of lease term or estimated useful life

Property, plant and equipment, gross 8,414 6,744

Property, plant and equipment, net $ 3,166 $ 1,790

Depreciation expense for the years ended December 31, 2025 and 2024 was $0.2 million and $0.1 million, respectively.

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DELCATH SYSTEMS, INC.

Notes to Consolidated Financial Statements

for the Years Ended December 31, 2025 and 2024

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

(9) Accrued Expenses

Current accrued expenses include the following:

Compensation, excluding taxes 4,248 3,471

(10) 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 years ended December 31, 2025 and 2024, the Company recognized $0.2 million of operating lease expense and $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 “Premises”). The initial term of the lease is five 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 December 31, 2025:

(In thousands) U.S. Ireland Total

Operating cash flows from operating leases $ (144) $ (46) $ (190)

Weighted average remaining lease term 8.1 0.6

Weighted average discount rate - operating leases 8 % 8 %

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DELCATH SYSTEMS, INC.

Notes to Consolidated Financial Statements

for the Years Ended December 31, 2025 and 2024

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

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

(In thousands) U.S. Ireland Total

Less present value discount (335) (1) (336)

(11) 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 December 31, 2025, the Company has designated the following preferred stock:

Designated Preferred Shares December 31, 2025

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DELCATH SYSTEMS, INC.

Notes to Consolidated Financial Statements

for the Years Ended December 31, 2025 and 2024

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

Preferred Stock

As of December 31, 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.

Share Repurchase Program

On November 19, 2025 the Company’s Board of Directors authorized a share repurchase program under which the Company may repurchase up to $25 million of its outstanding shares of common stock, from time to time, through open market transactions, privately negotiated transactions or in such other manners approved by the Board of Directors, in accordance with all applicable securities laws and regulations, including Rule 10b-18 of the Exchange Act. The Company may enter into a pre-arranged stock trading plan in accordance with the guidelines specified under Rule 10b5-1 to effectuate all or a portion of the share repurchase program. The repurchase program does not obligate the Company to purchase any shares and does not have an expiration date. The timing and method of any repurchases, which will depend on a variety of factors, including market conditions, are subject to our results of operations, financial condition, liquidity and other factors.

As of December 31, 2025, there have been 628,572 shares of common stock repurchased and retired under the repurchase program at an average price paid per share of $9.5254 for a total aggregate purchase price of approximately $6.0 million. The Company had approximately $19.0 million remaining under the stock repurchase authorization at December 31, 2025.

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 December 31, 2025, there have been 9,325,000 shares of common stock reserved under the 2020 Plan, which includes an additional 2,200,000 shares approved by shareholders on May 15, 2025, of which 2,470,507 remained available to be issued as of December 31, 2025 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.

Inducement 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

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DELCATH SYSTEMS, INC.

Notes to Consolidated Financial Statements

for the Years Ended December 31, 2025 and 2024

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

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 December 31, 2025, there have been 1,100,000 shares of common stock reserved under the 2023 Plan, of which 174,586 remain available to be granted.

Stock Options

The following table sets forth information as of December 31, 2025 with respect to compensation plans (including individual compensation arrangements) under which shares of common stock of the Company are authorized for issuance.

(1)Includes (a) stock options for an aggregate of 142 shares of common stock issued under the Company’s 2019 Equity Incentive Plan, which allows for grants in the form of incentive stock options, non-qualified stock options, stock units, stock awards, stock appreciation rights, and other stock-based awards to the Company’s officers, directors, employees, consultants, and advisors, including options to purchase shares of common stock at exercise prices not less than 100% of fair value on the dates of grant. As of November 2, 2020, no additional grants may be made under this plan, which has been superseded by the Company’s 2020 Omnibus Equity Incentive Plan; however, outstanding awards granted under this plan will remain outstanding and continue to be administered in accordance with the terms of this plan and the applicable award agreements; (b) pursuant to an employment agreement dated as of August 31, 2020 between the Company and Gerard Michel, the Company’s Chief Executive Officer, on October 1, 2020, a non-qualified and non-plan stock option “inducement award” to purchase 498,000 shares of the Company’s common stock in reliance on Nasdaq Rule 5635(c)(4) pursuant to the terms of a stock option award agreement between the Company and Mr. Michel; and (c) new hire inducement awards to purchase 1,235,110 shares of the Company’s common stock in reliance on Nasdaq Rule 5635(c)(4) pursuant to the terms of a stock option award agreement between the Company and 57 employees hired between 2022 and 2025.

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DELCATH SYSTEMS, INC.

Notes to Consolidated Financial Statements

for the Years Ended December 31, 2025 and 2024

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

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 assumption ranges for new grants during the reporting periods:

Years Ended December 31

Expected terms (years) 5.2 - 5.9 5.2 - 5.9

Risk-free interest rate 3.8% - 4.4% 3.7% - 4.7%

The following is a summary of stock option activity for the year ended December 31, 2025:

The weighted average grant-date fair value of the stock options granted during the years ended December 31, 2025 and 2024 was approximately $11.60 and $4.29 per share, respectively. The aggregate intrinsic value of stock options exercised was $3.0 million and $1.0 million for the years ended December 31, 2025 and December 31, 2024, respectively.Total cash received as a result of stock option exercises was $4.4 million and $1.7 million for the years ended December 31, 2025 and December 31, 2024, respectively. Upon exercise, new shares are issued from authorized and unissued shares.

The following is a summary of share-based compensation expense in the statement of operations for the twelve months ended December 31, 2025 and December 31, 2024:

Year Ended December 31,

Selling, general and administrative $ 15,556 $ 6,690

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DELCATH SYSTEMS, INC.

Notes to Consolidated Financial Statements

for the Years Ended December 31, 2025 and 2024

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

At December 31, 2025, there was approximately $12.0 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 0.9 years.

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 171,364 have been issued as of December 31, 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 applicable six-month offering period.

Common Stock Warrants

The following is a summary of common stock warrant activity for the year ended December 31, 2025:

Warrants Weighted AverageExercise Price

Warrants issued — —

The following table presents information related to common stock warrants at December 31, 2025:

Warrants Exercisable

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

(12) Net Income (Loss) Per Share

Basic net income (loss) per share is determined by dividing net income (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 (loss) per share is determined by dividing net income (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, stock purchased pursuant to the Company’s employee stock purchase plan, convertible notes and warrants calculated using the treasury stock method. In periods with reported net operating losses, all common stock options and warrants are generally deemed anti-dilutive such that basic net loss per share and diluted net loss per share are equal.

At both December 31, 2025 and 2024, the Company had 1,341,375 pre-funded warrants outstanding. The following tables provides a reconciliation of the weighted average shares outstanding calculation for the year-ended December 31, 2025 and 2024.

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DELCATH SYSTEMS, INC.

Notes to Consolidated Financial Statements

for the Years Ended December 31, 2025 and 2024

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

Weighted average number of basic shares outstanding

Year ended December 31,

Weighted average number of diluted shares outstanding

Year ended December 31,

Additional dilutive shares 4,098,400 —

For the years ended December 31, 2025 and 2024 the following potentially dilutive securities were excluded from the computation of diluted earnings per share because their effects would be antidilutive:

December 31,

Common stock warrants - equity — 1,851,900

Assumed conversion of preferred stock — 1,782,842

(13) Commitments and Contingencies

Litigation, Claims and Assessments

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) royalty on sales of CHEMOSAT units over a defined minimum for a period of five 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. Annual payments were made in May 2024 and 2025. The Company has estimated the remaining fair value of the settlement to be $0.9 million as of December 31, 2025 and recorded $0.6 million as other liabilities, non-current and $0.3 million as accrued expenses

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DELCATH SYSTEMS, INC.

Notes to Consolidated Financial Statements

for the Years Ended December 31, 2025 and 2024

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

on the Company’s consolidated balance sheet as of December 31, 2025. See Note 15 - Fair Value Measurements in our consolidated financial statements for further detail.

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 extend its term for 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. As of December 31, 2025, the Company has committed to purchase $2.5 million of melphalan under this Supply Agreement in 2026.

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.

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DELCATH SYSTEMS, INC.

Notes to Consolidated Financial Statements

for the Years Ended December 31, 2025 and 2024

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

(14) Income Taxes

The components of income tax provision (benefit) for the years ended December 31, 2025 and 2024 were as follows:

For the Year Ended December 31,

Current provision

Federal $ 12 $ —

Foreign 50 —

Total current provision $ 810 $ —

Deferred provision

Federal $ — $ —

State — —

Foreign — —

Total deferred provision $ — $ —

Total provision (benefit) for income taxes $ 810 $ —

Income (loss) before income taxes consists of:

For the Year Ended December 31,

The Company adopted ASU 2023-09 "Income Taxes (Topic 740): Improvements To Income Tax Disclosures" on a prospective basis beginning with the year ended December 31, 2025. The following table presents required disclosure pursuant to ASU 2023-09 and reconciles the U.S. federal statutory tax amount and rate to our actual global effective amount and rate for the year ended December 31, 2025:

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DELCATH SYSTEMS, INC.

Notes to Consolidated Financial Statements

for the Years Ended December 31, 2025 and 2024

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

For the Year Ended December 31, 2025

(In thousands) Amount Percentage

U.S. federal statutory tax rate 735 20.9 %

State and local income taxes, net of federal income tax effect (1) 591 16.8 %

Foreign tax effects

Ireland

Statutory tax rate difference between Ireland and the United States (79) (2.3) %

Changes in valuation allowances 157 4.5 %

Provision to return (236) (6.7) %

Nondeductible expenses (37) (1.1) %

United Kingdom

Changes in valuation allowances — — %

Provision to return — — %

Nondeductible expenses 50 1.4 %

Germany

Statutory tax rate difference between Germany and the United States (4) (0.1) %

Changes in valuation allowances — — %

Provision to return — — %

Nondeductible expenses 45 1.3 %

Other countries (7) (0.2) %

Effect of changes in tax laws or rates enacted in the current period — — %

Effect of cross-border tax laws

Global intangible low-taxed income 52 1.5 %

Foreign disregarded entity branch inclusion 195 5.6 %

DCTH US Equity

DCTH · 10-K · period ended 2025-12-31

Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations.

Item 7A. Quantitative and Qualitative Disclosures About Market Risk

Item 8. Financial Statements and Supplementary Data

DCTH US Equity☆

DCTH · 10-K · period ended 2025-12-31

Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations.

Item 7A. Quantitative and Qualitative Disclosures About Market Risk

Item 8. Financial Statements and Supplementary Data

DCTH US Equity