CELLDEX THERAPEUTICS,INC. (NASDAQ:CLDX) Files An 8-K Material Modification to Rights of Security Holders
Item 3.03.Material Modification to Rights of Security Holders.

To the extent required by Item 3.03 of Form8-K, the information contained in Item 5.03 below is incorporated by reference into this Item 3.03.

Item 5.03.Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year.

On February8, 2019, Celldex Therapeutics,Inc. (the “Company”) filed a Certificate of Amendment to the Company’s Third Restated Certificate of Incorporation with the Secretary of State of the State of Delaware (the “Certificate of Amendment”), which effected, immediately upon filing, a one-for-fifteenreverse stock split(the “Reverse Stock Split”) of the Company’s issued and outstanding common stock, $0.001 par value per share (the “Common Stock”).

As a result of theReverse Stock Split, every fifteen shares of Common Stock issued and outstanding was converted into one share of Common Stock and the total number of shares of Common Stock outstanding will be reduced from approximately 181.8 million shares to approximately 12.1 million shares. No fractional shares were issued in connection with theReverse Stock Split. Stockholders who would otherwise be entitled to a fractional share of Common Stock are instead entitled to receive a proportional cash payment.

TheReverse Stock Splitdid not change the par value of the Common Stock or the authorized number of shares of Common Stock. All outstanding stock options entitling their holders to purchase shares of Common Stock were adjusted as a result of theReverse Stock Split, as required by the terms of these securities.

As previously disclosed, at the Company’s 2018 Annual Meeting of Stockholders held on June13, 2018 (the “Annual Meeting”) the stockholders of the Company approved a proposal to amend the Company’s Third Restated Certificate of Incorporation to effect areverse stock splitof the Common Stock at a ratio in the range of one-for-ten to one-for-fifteen at the discretion of the Board of Directors of the Company (the “Board”). to the authority granted by the Company’s stockholders at the Annual Meeting, the Board approved the Reverse Stock Split.

Trading of the Common Stock on aReverse Stock Split-adjusted basis on the Nasdaq Capital Market will begin at the opening of trading on February11, 2019. In connection with theReverse Stock Split, the Common Stock will also commence trading with a new CUSIP number, 15117B202, at such time.

Computershare Trust Company, N.A., the Company’s transfer agent, is acting as the exchange agent for theReverse Stock Splitand will provide instructions to stockholders of record regarding the process for exchanging shares. Those stockholders holding Common Stock in “street name” will receive instructions from their brokers.

The summary of the Certificate of Amendment does not purport to be complete and is qualified in its entirety by reference to the full text of the Certificate of Amendment, a copy of which is attached hereto as Exhibit3.1 and is incorporated herein by reference.

On February8, 2019, the Company issued a press release with respect to theReverse Stock Split, a copy of which is being furnished as Exhibit99.1 to this Form8-K.