Unum Therapeutics Inc. entered into an amendment (the Second Amendment) to the loan security agreement, dated as of January 19, 2017 (as amended, amended and restated, supplemented or otherwise modified prior to the Second Amendment, the Loan Security Agreement), by and between the Company and Pacific Western Bank. Pursuant to the Second Amendment, (i) the draw deadline was extended to June 30, 2019, (ii) the interest only period was extended until June 30, 2020 with a potential additional extension to March 31, 2021 if additional capital is raised, (iii) a 24-month interest and principal period was extended to start following the end of the amended interest only period, (iv) the primary depository requirements with Pacific Western Bank were increased, and (v) a facility fee was added.