Filed Pursuant to Rule 424(b)(3)
Registration No. 333-272659
Up to 19,509,749 Shares of Common Stock Offered by the Selling Stockholders
This prospectus relates to the offer and resale, from time to time, by the selling stockholders named under the heading Selling
Stockholders in this prospectus, or their assigns (the Selling Stockholders), of up to 19,509,749 shares (the Shares) of the Companys Common Stock, par value $0.01 per share (the Common Stock) which
consist of (i) 2,916,358 shares of Common Stock, issuable upon conversion of 9,624 shares of Series F-2 Convertible Preferred Stock, par value $0.01 per share (the Series F-2 Preferred Stock), (ii) 7,746,436 shares of Common Stock issuable upon conversion of 34,860 shares of F-3 Preferred Stock exercisable pursuant to the preferred
stock tranche A warrants (the Preferred Tranche A Warrant) to acquire shares of Series F-3 Preferred Stock, par value $0.01 per share (the Series F-3
Preferred Stock), (iii) 4,149,994 shares of Common Stock issuable upon conversion of 24,900 shares of F-4 Preferred Stock exercisable pursuant to the preferred stock tranche B warrants (the
Preferred Tranche B Warrant, together with the Preferred Tranche A Warrant, the Preferred Warrants) to acquire shares of Series F-4 Preferred Stock, par value $0.01 per share
(the Series F-4 Preferred Stock and together with the Series F-3 Preferred Stock, the Preferred Warrant Shares), (iv) 4,649,185 shares of
Common Stock, (v) 31,110 shares of Common Stock, issuable upon exercise of the common stock tranche A warrants (Common Tranche A Warrant) and (vi) 16,666 shares of Common Stock issuable upon exercise of common stock tranche B
warrants (the Common Tranche B Warrant, together with the Common Tranche A Warrant, the Common Warrants, and together with the Preferred Warrants, the Warrants).
We are registering the offer and sale of the Shares held by the Selling Stockholders to satisfy the registration rights they were granted
pursuant to the Preferred Purchase Agreement (as defined below) and the Common Purchase Agreement (as defined below) (together, the Purchase Agreements). While we will not receive any proceeds from the sale of the Shares by the Selling
Stockholders, we will receive proceeds from the exercise of any Warrants for cash.
Our registration of the Shares covered by this
prospectus does not mean that the Selling Stockholders will offer or sell such Shares. The Selling Stockholders may sell the Shares covered by this prospectus in a number of different ways and at varying prices. For additional information on the
possible methods of sale that may be used by the Selling Stockholders, you should refer to the section of this prospectus entitled Plan of Distribution. The Selling Stockholders may, individually but not severally, be deemed to be an
underwriter within the meaning of the Securities Act of 1933, as amended (the Securities Act), of the Shares that they are offering pursuant to this prospectus. The Selling Stockholders will bear all commissions and
discounts, if any, attributable to their respective sales of the Shares hereunder. We will bear all costs, expenses and fees in connection with the registration of the Shares. We will not be paying any underwriting discounts or commissions in this
offering.
A prospectus supplement may add, update, or change information contained in this prospectus. You should carefully read this
prospectus, any applicable prospectus supplement, and the information incorporated by reference in this prospectus and any applicable prospectus supplement before you make your investment decision.
Our Common Stock is traded on The Nasdaq Capital Market under the symbol DCTH. On June 27, 2023, the closing price for our
Common Stock, as reported on The Nasdaq Capital Market, was $6.06 per share.
Investing in
these securities involves certain risks. See Risk Factors on page 6 of this prospectus. See also Risk Factors in the documents incorporated by reference in this prospectus for a discussion of the
factors you should carefully consider before deciding to purchase these securities.
Neither the SEC nor any state securities
commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.
The date of this prospectus is June 28, 2023