UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): November 19, 2025

DELCATH SYSTEMS, INC.

(Exact Name of Registrant as Specified in its Charter)

Delaware

001-16133

06-1245881

(State or other jurisdiction
of incorporation or organization)

(Commission

File Number)

(IRS Employer
Identification No.)

566 Queensbury Avenue

Queensbury, NY 12804

(Address of principal executive offices) (Zip Code)

(212) 489-2100

(Registrant’s telephone number, including area code)

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐	Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐	Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐	Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐	Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class

Trading

symbol(s)

Name of each exchange
on which registered

Common Stock, $.01 par value

DCTH

The Nasdaq Capital Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (17 CFR §230.405) or Rule 12b-2 of the Securities Exchange Act of 1934 (17 CFR §240.12b-2).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 8.01

Other Events.

On November 19, 2025, the board of directors of Delcath Systems, Inc., a Delaware corporation (the “Company”) 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, subject to market conditions.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the Registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

DELCATH SYSTEMS, INC.

Date: November 20, 2025

/s/ Gerard Michel

Gerard Michel

Chief Executive Officer

DELCATH SYSTEMS, INC. 8-K