WASHINGTON, D.C. 20549 FORM 10-Q UNITED STATES SECURITIES AND EXCHANGE COMMISSION ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2021 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-36112 MACROGENICS, INC. (Exact name of registrant as specified in its charter) Delaware 06-1591613 (State or other jurisdiction of incorpo ...