Exhibit 99.1

Delcath Systems Reports Third Quarter 2026
Results and Business Highlights

Increases 2026 Revenue Guidance to a Range of $115 million to $117 million
Conference Call Today at 8:30 a.m. Eastern Time

QUEENSBURY, NY – November 9, 2026, Delcath Systems, Inc. (Nasdaq: DCTH), an interventional oncology company focused on the treatment of primary and metastatic liver cancers, today announced financial results and business highlights for the third quarter ended September 30, 2026.

Third Quarter 2026 Financial Results
•Total revenue of $35.1 million, compared with $20.6 million in the third quarter of 2025
◦HEPZATO KIT™ revenue of $32.7 million, compared to $19.3 million in the third quarter of 2025
◦CHEMOSAT® revenue of $2.4 million, compared to $1.3 million in the third quarter of 2025
•Gross margins of 89%, compared to 87% in the third quarter of 2025
•Net income of $7.0 million, compared to $0.8 million in the third quarter of 2025
•Non-GAAP adjusted EBITDA of $11.5 million, compared to $5.3 million in the third quarter of 2025
•Cash provided by operations of $8.2 million in the quarter; compared to $4.8 million in the third quarter of 2025
•Cash and investments of $104.3 million as of September 30, 2026; and no debt

Business Highlights
•Currently 33 active treatment centers
•Approximately 72% growth in HEPZATO volume in the third quarter 2026 compared to the third quarter 2025
•Advanced the global Phase 2 DELUMA trial (NCT06875128), evaluating HEPZATO in combination with standard-of-care therapy versus standard of care alone in liver-dominant HER2-negative metastatic breast cancer; first patient dosed July 9, 2026, at the European Institute of Oncology in Milan, Italy. The randomized trial is designed to enroll approximately 90 patients at more than 20 U.S. and European sites.

“We are pleased with the continued momentum in our business, with meaningful progress across both commercial operations and clinical development,” said Gerard Michel, Chief Executive Officer of Delcath Systems. “Growing physician experience with HEPZATO, strong engagement across our treatment center network, and increasing interest in its use alongside systemic therapies reinforce our confidence in the long-term opportunity. We are also expanding our pipeline, with a planned IND submission for cholangiocarcinoma in early 2027 and, pending FDA agreement, completion of ongoing preclinical development of an oxaliplatin-based PHP product by mid-2027.”

2026 Full Year Financial Guidance
The Company’s financial outlook for fiscal year 2026:
•Total HEPZATO KIT and CHEMOSAT revenue to range from $115 million to $117 million, reflecting an increase in HEPZATO KIT volume of at least 41% over 2025
•Full year gross margins in the range of 87% to 89%
•Positive adjusted EBITDA
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Exhibit 99.1
Third Quarter 2026 Results
Total revenue for the quarter ending September 30, 2026 was $35.1 million compared to $20.6 million for the same period in the prior year. Revenue in the quarter includes sales of $32.7 million of HEPZATO in the U.S. and $2.4 million of CHEMOSAT in Europe.
Research and development expenses for the quarter ending September 30, 2026, were $11.0 million compared to $8.0 million for the same period in the prior year. The increase is primarily due to increased clinical headcount and increased clinical trial activity.

Selling, general and administrative expenses for the quarter ended September 30, 2026, were $13.1 million compared to $10.3 million for the same period in the prior year. The increase is primarily due to continued commercial expansion activities.
Net income was $7.0 million for the quarter ended September 30, 2026, compared to $0.8 million for the same period in the prior year.
Non-GAAP adjusted EBITDA for the quarter ended September 30, 2026 was $11.5 million compared to adjusted EBITDA of $5.3 million for the same period in the prior year. A table reconciling non-GAAP measures is included in this press release for reference.
As of September 30, 2026, the Company had $104.3 million in cash and investments, and no debt.

Conference Call Information
To participate in this event, dial in approximately 5 to 10 minutes before the beginning of the call.

Event Date: Monday, November 9, 2026
Time: 8:30 AM Eastern Time

Participant Numbers:
Toll Free: 1-800-717-1738
International: 1-646-307-1865
Webcast: https://viavid.webcasts.com/starthere.jsp?ei=1767384&tp_key=cbc23b55c8

A replay of the webinar will be available shortly after the conclusion of the call and will be archived on the company's website https://investors.delcath.com/news-events/events-and-presentations.

GAAP v. Non-GAAP Measures
Delcath’s reported earnings are prepared in accordance with generally accepted accounting principles in the United States, or GAAP, and represent earnings as reported to the Securities and Exchange Commission. Delcath has provided in this release certain financial information that has not been prepared in accordance with GAAP. Delcath’s management believes that the non-GAAP adjusted EBITDA described in this release, which includes adjustments for specific items that are generally not indicative of our core operations, provides additional information that is useful to investors in understanding Delcath’s underlying performance, business and performance trends, and helps facilitate period-to-period comparisons and comparisons of its financial measures with other companies in Delcath’s industry. However, the non-GAAP financial measures that Delcath uses may differ from measures that other companies may use. Non-GAAP financial measures are not required to be uniformly applied, are not audited and should not be considered in isolation or as substitutes for results prepared in accordance with GAAP.

About Delcath Systems, Inc., HEPZATO KIT and CHEMOSAT
Delcath Systems, Inc. is an interventional oncology company focused on the treatment of primary and metastatic liver cancers. The company's proprietary products, HEPZATO KIT™ (HEPZATO (melphalan) for Injection/Hepatic Delivery System) and CHEMOSAT® Hepatic Delivery System (HDS) for Melphalan percutaneous hepatic perfusion (PHP), are designed to administer high-dose chemotherapy to the liver while controlling systemic exposure and associated side effects during a PHP procedure.
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Exhibit 99.1

In the United States, HEPZATO KIT is considered a combination drug and device product and is regulated and approved for sale as a drug by the FDA. HEPZATO KIT is comprised of the chemotherapeutic drug melphalan and Delcath’s proprietary HDS. The HDS is used to isolate the hepatic venous blood from the systemic circulation while simultaneously filtrating hepatic venous blood during melphalan infusion and washout. The use of the HDS results in loco-regional delivery of a relatively high melphalan dose, which can potentially induce a clinically meaningful tumor response with minimal hepatotoxicity and reduce systemic exposure. HEPZATO KIT is approved in the United States as a liver-directed treatment for adult patients with metastatic uveal melanoma (mUM) 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. Please see the full Prescribing Information, including BOXED WARNING for the HEPZATO KIT.

In Europe, the device-only configuration of the HDS is regulated as a Class III medical device and is approved for sale under the trade name CHEMOSAT Hepatic Delivery System for Melphalan, or CHEMOSAT, where it has been used in the conduct of percutaneous hepatic perfusion procedures at major medical centers to treat a wide range of cancers of the liver.

Safe Harbor / Forward-Looking Statements
The Private Securities Litigation Reform Act of 1995 provides a safe harbor for forward-looking statements made by the Company or on its behalf. This press release contains forward-looking statements, including the Company’s statements regarding the possible synergy seen in the successful Phase 2 CHOPIN Trial being transferable to clinical practice; Company’s 2026 financial outlook, which are subject to certain risks and uncertainties, that can cause actual results to differ materially from those described. The words “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “plan,” “potential,” “predict,” “project,” “should,” “target,” “will,” “would” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Factors that may cause such differences include, but are not limited to, uncertainties relating to: the Company’s commercialization plans and its ability to successfully commercialize the HEPZATO KIT; contributions to adjusted EBITDA; the Company’s successful management of the HEPZATO KIT supply chain, including securing adequate supply of critical components necessary to manufacture and assemble the HEPZATO KIT; successful FDA inspections of the facilities of the Company and those of its third-party suppliers/manufacturers; the Company’s successful implementation and management of the HEPZATO KIT Risk Evaluation and Mitigation Strategy; the potential benefits of the HEPZATO KIT as a treatment for patients with primary and metastatic disease in the liver; the Company’s ability to obtain reimbursement for the HEPZATO KIT; and the Company’s ability to successfully enter into any necessary purchase and sale agreements with users of the HEPZATO KIT. For additional information about these factors, and others that may impact the Company, please see the Company’s filings with the Securities and Exchange Commission, including those on Forms 10-K, 10-Q, and 8-K. However, new risk factors and uncertainties may emerge from time to time, and it is not possible to predict all risk factors and uncertainties. Accordingly, you should not place undue reliance on these forward-looking statements, which speak only as of the date they are made. We undertake no obligation to publicly update or revise these forward-looking statements to reflect events or circumstances after the date they are made.

Investor Relations Contact:
ICR Healthcare
investorrelations@delcath.com
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Exhibit 99.1

DELCATH SYSTEMS, INC.
Condensed Consolidated Balance Sheets
(Unaudited)
(in thousands, except share and per share data)
September 30,
2026
December 31,
2025
Assets
Current assets
Cash and cash equivalents$55,538 $43,454 
Short-term investments48,777 47,582 
Accounts receivable20,214 11,744 
Inventories10,501 10,252 
Prepaid expenses and other current assets6,525 6,498 
Total current assets141,555 119,530 
Property, plant and equipment, net5,127 3,166 
Right-of-use assets2,408 936 
Total assets$149,090 $123,632 
Liabilities and Stockholders’ Equity
Current liabilities
Accounts payable$3,475 $2,658 
Accrued expenses9,351 8,191 
Lease liabilities, current196 101 
Total current liabilities13,022 10,950 
Lease liabilities, non-current2,212 835 
Other liabilities, non-current319 628 
Total liabilities$15,553 $12,413 
Commitments and contingencies
Stockholders’ equity
Preferred stock, $0.01 par value; 10,000,000 shares authorized; 14,192 and 14,192 shares issued and outstanding at September 30, 2026 and December 31, 2025, respectively
— — 
Common stock, $0.01 par value; 80,000,000 shares authorized; 34,771,239 shares and 34,691,671 shares issued and outstanding at September 30, 2026 and December 31, 2025, respectively
348 347 
Additional paid-in capital653,118 639,145 
Accumulated deficit(520,298)(528,848)
Accumulated other comprehensive income369 575 
Total stockholders’ equity133,537 111,219 
Total liabilities and stockholders’ equity$149,090 $123,632 

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Exhibit 99.1
DELCATH SYSTEMS, INC.
Condensed Consolidated Statements of Operations and Comprehensive Income
(Unaudited)
(in thousands, except share and per share data)

Three months ended September 30,Nine months ended September 30,
2026202520262025
Product revenue$35,102 $20,563 $89,229 $64,503 
Cost of goods sold(3,918)(2,624)(10,639)(8,787)
Gross profit31,184 17,939 78,59055,716
Operating expenses:
Research and development expenses11,011 7,986 31,21519,875
Selling, general and administrative expenses13,057 10,341 39,50132,997
Total operating expenses24,068 18,327 70,71652,872
Operating income
7,116 (388)7,874 2,844 
Interest income
852 796 2,420 2,063 
Other expense
(1)(33)(76)$(63)
Income before income taxes
7,967 375 10,218 4,844 
Income tax expense (benefit)
1,015 (455)1,668 248 
Net income
6,952 830 8,550 4,596 
Other comprehensive income (loss):
Unrealized gain on investments adjustments115 296 (135)592 
Foreign currency translation adjustments(4)(13)(71)201 
Total comprehensive income
$7,063 $1,113 $8,344 $5,389 
Common share data:
Basic income per common share
$0.19 $0.02 $0.24 $0.13 
Weighted average number of basic shares outstanding36,074,34836,383,27735,996,01935,610,619
Diluted income per common share
$0.17 $0.02 $0.21 $0.12 
Weighted average number of dilutive shares outstanding41,019,55340,056,81440,059,10339,949,941
DELCATH SYSTEMS, INC.
Reconciliation of Reported Net Income (GAAP) to Adjusted EBITDA (NON-GAAP Measure)
(Unaudited)
(in thousands)
Three months ended September 30,Nine months ended September 30,
2026202520262025
Net income$6,952 $830 $8,550 $4,596 
Stock-based compensation expense4,233 5,648 14,297 19,720 
Depreciation 153 64 368 158 
Interest income(852)(796)(2,420)(2,063)
Income tax expense1,015 (455)1,668 248 
Adjusted EBITDA (Non-GAAP)$11,501 $5,291 $22,463 $22,659 
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