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): July 31, 2019

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 July 31, 2019, Unum Therapeutics Inc. (the “Company”) entered into an amendment (the “Fourth Amendment”) to the loan security agreement, dated as of January 19, 2017 (as amended, amended and restated, supplemented or otherwise modified prior to the Fourth Amendment, the “Loan Security Agreement”), by and between the Company and Pacific Western Bank. The Fourth Amendment amends the Loan Security Agreement to, among other things, provide for changes to the primary depository requirements with Pacific Western Bank.

The above description of the Fourth Amendment does not purport to be complete and is qualified in its entirety by reference to the full text of the Fourth Amendment, which is filed with this Current Report on Form 8-K as Exhibit 10.1 and is incorporated herein by reference.

Item 9.01 Financial Statements and Exhibits.

(d) 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.

Exhibit 10.1

FOURTH AMENDMENT

TO

LOAN AND SECURITY AGREEMENT

This Fourth Amendment to Loan and Security Agreement (this “Amendment”) is entered into as of July 31, 2019, by and between PACIFIC WESTERN BANK, a California state chartered bank (“Bank”), and UNUM THERAPEUTICS INC. (“Borrower”).

RECITALS

Borrower and Bank are parties to that certain Loan and Security Agreement dated as of January 19, 2017 (as amended from time to time, the “Agreement”). The parties desire to amend the Agreement in accordance with the terms of this Amendment.

NOW, THEREFORE, the parties agree as follows:

6.6 Primary Depository. Borrower shall at all times maintain at least the lesser of $50,000,000 or substantially all of its cash in depository and operating accounts with Bank or its Affiliates. Without limitation of the foregoing, of the foregoing cash balances maintained with Bank and its Affiliates, (i) until the Term Loan has been funded in accordance with Section 2.1(b)(i), Borrower shall maintain at least the lesser of $50,000,000 or substantially all cash in accounts with Bank, and (ii) after the Term Loan has been funded in accordance with Section 2.1(b)(i), Borrower shall maintain at least the lesser of $15,000,000 or substantially all of the foregoing cash balance in accounts with Bank. Borrower may maintain any excess amounts with other financial institutions, provided that Borrower, Bank, and any such financial institution shall have entered into an account control agreement with respect to any such accounts, in form and substance satisfactory to Bank. Notwithstanding the above, (x) Borrower may maintain the Silicon Valley Bank Cash Collateral Account at Silicon Valley Bank provided that the balance does not exceed $1,255,400 at any time, (y) Borrower may maintain an aggregate amount not to exceed $10,000,000 in its operating account held at Silicon Valley Bank until September 29, 2019, after which all cash in any accounts held at Silicon Valley Bank, unless otherwise permitted herein, shall be transferred to Bank, and (z) Borrower may maintain a collateral account at Silicon Valley Bank with an amount not exceeding $250,000 at any time to secure reimbursement obligations under corporate credit cards. For the avoidance of doubt, no account control agreements in favor of Bank shall be required with respect to any accounts permitted under these clauses (x), (y) and (z). Borrower may transfer cash to the MSC Subsidiary so long as the MSC Investment Conditions have been met.

(n) Indebtedness not to exceed $250,000 in the aggregate outstanding at any time arising under a credit card facility provided by Silicon Valley Bank.

(m) Liens on Cash in a collateral account with Silicon Valley Bank in an amount not to exceed $250,000 at any time securing reimbursement obligations under a credit card facility provided by Silicon Valley Bank.

[Signature Page Follows]

IN WITNESS WHEREOF, the undersigned have executed this Amendment as of the first date above written.

[Signature Page to Fourth Amendment to Loan and Security Agreement]