DELCATH SYSTEMS, INC. (DCTH)

Results of Operations

Revenue

The increase in total revenue for the three and six months ended June 30, 2026 compared to the same period in 2025 was due to the continued commercial expansion and demand of HEPZATO in the United States.

Our revenue is generated from a relatively concentrated group of customers. For the six months ended June 30, 2026, two customers each accounted for more than 10% of our total product revenue, representing in the aggregate approximately 29.2% of revenue. As of June 30, 2026, our largest customer by revenue accounted for approximately 19.0% of our total accounts receivable balance of $15.9 million. Our standard payment terms are 30 to 60 days, and we have not experienced material collection losses to date. However, as our commercial business scales, the absolute dollar concentration of our receivables with a limited number of large hospital or treatment center customers increases. A payment delay, dispute, or reduction in ordering activity by one or more significant customers could adversely affect our operating cash flow in any given period. We actively

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monitor our receivables aging and have not applied any estimated credit loss reserves against our accounts receivable balance as of June 30, 2026.

Cost of Goods Sold

The change in cost of goods sold for the three and six months ended June 30, 2026 compared to the same period in 2025 is directly related to changes in demand for product revenue, offset by decreases in supplemental wages.

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 three and six months ended June 30, 2026 compared to the same period in 2025 is due to the continued costs associated with expanding the clinical team, including the base and supplemental wages related to an increase in headcount, and continuation of the Phase 2 clinical trials evaluating HEPZATO in combination with standard of care for mCRC and mBC. In addition to the Phase 2 clinical trials, we are researching initiatives to explore different indications, combinations, and potential applications of our therapies.

Selling, General and Administrative Expenses

Selling, general and administrative expenses consist primarily of payroll, rent and professional services such as accounting, legal, marketing and commercial preparation services. For the three and six months ended June 30, 2026 compared to the same period in 2025, selling, general and administrative expenses increased due to continued commercial expansion activities including marketing-related travel expenses and additional personnel on the commercial team.

Interest and other Income/Expense

Interest and other income is primarily related to the interest income associated with marketable securities and cash on hand. There was no interest expense for the three and six months ended June 30, 2026 and 2025 due to all debt being paid off in 2024.

Liquidity and Capital Resources

Cash Flows

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

At June 30, 2026, we had cash and cash equivalents totaling $47.5 million and short-term investments totaling $48.4 million, as compared to cash and cash equivalents totaling $34.4 million and short-term investments totaling $46.6 million at June 30, 2025.

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 these condensed consolidated financial statements. Our actual future liquidity and capital requirements will depend on numerous factors, including revenues recognized by us, 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

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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 June 30, 2026, there have been 945,665 shares of common stock repurchased and retired under the repurchase program at an average price paid per share of $9.5085 for a total aggregate purchase price of approximately $9.0 million, which includes 628,572 shares repurchased prior to 2026 for an aggregate purchase price of approximately $6.0 million. We had approximately $16.0 million remaining under the share repurchase program at June 30, 2026.

Capital Commitments

Our capital commitments over the next twelve months include $13.3 million to satisfy accounts payable, accrued expenses, current lease liabilities and current portion of the medac settlement which includes $1.7 million to purchase melphalan under the Supply Agreement discussed in “Note 12 - Commitments and Contingencies”. Additional capital commitments beyond the next twelve months include (a) $2.3 million of lease liabilities and (b) $0.3 million for settlement of litigation with medac.

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.

Critical Accounting Estimates

Management has completed its quarterly evaluation of estimates and there have been no material changes to the process of our critical accounting estimates as they were reported in our Annual Report on Form 10-K filed with the SEC on February 26, 2026.

Application of Critical Accounting Policies

Our financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America. There were no material changes to our critical accounting policies as reported in our Annual Report. A description of certain accounting policies that may have a significant impact on amounts reported in the financial statements is disclosed in “Note 3 – Summary of Accounting Policies” to the notes to the consolidated financial statements contained in our Annual Report.

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.

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.

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; p0.001) and ORR of 76.3% in the combination group versus 39.5% (p0.001). Grade 3 or higher treatment-related adverse events were more frequent in the combination group (81.6% versus 40.5%, P0.001), 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:

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 commitmen

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