Delcath Systems (DCTH) 8-K Delcath Systems Closes Private Placement of $5.0 Million

Exhibit 99.1

Delcath Systems Closes Private Placement of $5.0 Million

NEW YORK, July 20, 2022 — Delcath Systems, Inc. (Nasdaq: DCTH), an interventional oncology company focused on the treatment of primary and metastatic cancers of the liver, today announced the closing of the previously announced private placement for the issuance and sale of 690,954 shares of common stock (the “Common Stock”) and 566,751 pre-funded warrants to purchase Common Stock (the “Pre-Funded Warrants”) to certain investors. Each share of Common Stock was sold at a price per share of $3.98 and the Pre-Funded Warrants were sold at a price of $3.97 per Pre-Funded Warrant. The Pre-Funded Warrants have an exercise price of $0.01 per share of Common Stock and are immediately exercisable.

Delcath received gross proceeds from the Private Placement of approximately $5.0 million before deducting offering expenses payable by Delcath. Delcath intends to use the net proceeds from the Private Placement for working capital purposes and other general corporate purposes.

The securities sold in the Private Placement, including the shares of common stock underlying the Pre-Funded Warrants, have not been registered under the Securities Act of 1933, as amended, or state securities laws as of the time of issuance and may not be offered or sold in the United States absent registration with the Securities and Exchange Commission (“SEC”) or an applicable exemption from such registration requirements. Delcath has agreed to file one or more registration statements with the SEC registering the resale of the Common Stock and the shares issuable upon exercise of the Pre-Funded Warrants purchased in the Private Placement.

This press release shall not constitute an offer to sell or a solicitation of an offer to buy these securities nor shall there be any sale of these securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction.

About Delcath Systems, Inc.

Delcath Systems, Inc. is an interventional oncology company focused on the treatment of primary and metastatic liver cancers. The Company’s proprietary percutaneous hepatic perfusion (PHP) system is designed to administer high-dose chemotherapy to the liver while controlling systemic exposure and associated side effects. In the United States, the PHP system is being developed under the tradename HEPZATO^TM KIT (melphalan hydrochloride for injection/hepatic delivery system), or HEPZATO, for the treatment of patients with unresectable hepatic-dominant metastatic ocular melanoma (mOM), also known as metastatic uveal melanoma (mUM) and is considered a combination drug and device product regulated by the United States Food and Drug Administration (FDA).

In Europe, the PHP system is now regulated as a Class lll medical device 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 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 news release contains forward-looking statements, which are subject to certain risks and uncertainties that can cause actual results to differ materially from those described, in particular, the expected uses of the proceeds from the Private Placement. Factors that may cause such differences include, but are not limited to, uncertainties relating to: the timing and results of the Company’s clinical trials, including without limitation the mOM and ICC clinical trial programs, as well as the receipt of additional data and the performance of additional analyses with respect to the mOM clinical trial, our determination whether to continue the ICC clinical trial program or to focus on other alternative indications, and timely monitoring and treatment of patients in the global Phase 3 mOM clinical trial and the impact of the COVID-19 pandemic on the completion of our clinical trials; the impact of the presentations at major medical conferences and future clinical results consistent with the data presented; approval of Individual Funding Requests for reimbursement of the CHEMOSAT procedure; the impact, if any, of ZE reimbursement on potential CHEMOSAT product use and sales in Germany; clinical adoption, use and resulting sales, if any, for the CHEMOSAT system to deliver and filter melphalan in Europe including the key markets of Germany and the UK; the Company’s ability to successfully commercialize the HEPZATO KIT/CHEMOSAT system and the potential of the HEPZATO KIT/CHEMOSAT system as a treatment for patients with primary and metastatic disease in the liver; our ability to obtain reimbursement for the CHEMOSAT system in various markets; approval of the current or future HEPZATO KIT/CHEMOSAT system for delivery and filtration of melphalan or other chemotherapeutic agents for various indications in the U.S. and/or in foreign markets; actions by the FDA or foreign regulatory agencies; the Company’s ability to successfully enter into strategic

partnership and distribution arrangements in foreign markets and the timing and revenue, if any, of the same; uncertainties relating to the timing and results of research and development projects; and uncertainties regarding the Company’s ability to obtain financial and other resources for any research, development, clinical trials and commercialization activities. These factors, and others, are discussed from time to time in our filings with the Securities and Exchange Commission. 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.

Contact:

Anthony Dias, Vice President of Finance

Email: TDias@delcath.com