UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 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): March 19, 2020

UNUM THERAPEUTICS INC.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code (617) 945-5576

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:

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

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

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 1.01 Entry into a Material Definitive Agreement.

On March 19, 2020, Unum Therapeutics Inc. (“we,” “us,” “our,” “Unum” or the “Company”) entered into a Purchase Agreement with Lincoln Park Capital Fund, LLC (“LPC”), pursuant to which we may elect to sell to LPC up to $25,000,000 in shares of our common stock, subject to certain limitations and conditions set forth in the Purchase Agreement..

Pursuant to the Purchase Agreement, on any business day over the 36-month term of the Purchase Agreement we have the right at our discretion and subject to certain conditions to direct LPC to purchase up to $25,000,000 in shares of our common stock. The purchase price of the common stock will be based upon the prevailing market price of common stock at the time of the purchase without any fixed discount. In addition, we may direct LPC to purchase additional amounts as accelerated purchases and additional accelerated purchases under certain circumstances. We are not obliged to sell any shares of common stock pursuant to the Purchase Agreement, and we will control the timing and amount of any such sales, but in no event will LPC be required to purchase more than $2,000,000 in shares of our common stock in any single regular purchase (excluding accelerated or additional accelerated purchases).

Concurrently with the execution of the Purchase Agreement on March 19, 2020, we entered into a Registration Rights Agreement pursuant to which we agreed to file a prospectus supplement pursuant to Rule 424(b) relating to the sale of shares of common stock to be issued and sold to LPC under the Purchase Agreement under our effective shelf registration statement or a new registration statement and to use our reasonable best efforts to keep such registration statement effective during the term of the Purchase Agreement.

The offer and sale of the shares under the Purchase Agreement is being made pursuant to the registration statement on Form S-3 (Registration No. 333-230678), filed with the Securities and Exchange Commission in accordance with the provisions of the Securities Act of 1933, as amended, and declared effective on May 1, 2019 and the prospectus supplement thereto dated March 20, 2020.

The Purchase Agreement contains customary representations, warranties, indemnification rights and other obligations and agreements of the Company and LPC. There are no limitations and conditions to completing future transactions other than a prohibition against entering into a “Variable Rate Transaction” as defined in the Purchase Agreement. There is no upper limit on the price per share that LPC could be obligated to pay for our common stock. We have the right to terminate the Purchase Agreement at any time, at no cost or penalty. Whether or to what extent we sell shares of common stock to LPC under the Purchase Agreement will depend on a variety of factors to be determined by the company from time to time, including, among others, our net revenue and other results of operations, our working capital and other funding needs, the prevailing market prices of our common stock and the availability of other sources of funding and we cannot sell stock to LPC on a day where our closing price is below the floor price as described in the Purchase Agreement. As consideration for LPC’s commitments under the Purchase Agreement, we will issue to LPC 726,382 shares of common stock.

This Current Report on Form 8-K shall not constitute an offer to sell or a solicitation of an offer to buy any shares of common stock, nor shall there be any sale of shares of common stock in any state or jurisdiction in which such an offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or other jurisdiction.

The Purchase Agreement and Registration Rights Agreement are filed as Exhibits 10.1 and 10.2, to this Current Report on Form 8-K and incorporated herein by reference. The foregoing descriptions of such agreements and the transactions contemplated thereby are qualified in their entirety by reference to such exhibits. In addition, the Purchase Agreement and Registration Rights Agreement have been included to provide investors with information regarding its terms. The Purchase Agreement and Registration Rights Agreement are not intended to provide any other information about the company. The Purchase Agreement contains representations and warranties that the company has made to LPC. The assertions embodied in those representations and warranties are qualified by information in confidential disclosure schedules that the company has provided to LPC in connection with signing the Purchase Agreement. The disclosure schedules may contain information that modifies, qualifies and creates exceptions to the representations and warranties set forth in the Purchase Agreement. Accordingly, investors should not rely on the representations and warranties as characterizations of the actual state of facts at the time they were made or otherwise.

Item 8.01 Other Events.

On March 20, 2020, we issued a press release announcing the entry into the Purchase Agreement, a copy of which is filed as Exhibit 99.1 to this Current Report and incorporated herein by reference.

Item 9.01 Financial Statements and Exhibits

(d) Exhibits

See the accompanying Index to Exhibits, which information is incorporated herein by reference.

INDEX TO EXHIBITS

SIGNATURES

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