X0306 4 2020-08-31 0 0001750019 TCR2 THERAPEUTICS INC. TCRR 0001760104 Cardama Alfonso Quintas TCR2 THERAPEUTICS INC. 100 BINNEY STREET CAMBRIDGE MA 02142 0 1 0 0 Chief Medical Officer Common Stock 2020-08-31 5 A 0 E 1118 10.098 A 3043 D Common Stock 2021-02-28 5 A 0 E 708 16.1245 A 3751 D The reporting person is voluntarily reporting the acquisition of shares of the issuer's common stock pursuant to the issuer's 2018 Employee Stock Purchase Plan ("ESPP") for the ESPP purchase period of March 1, 2020 through August 31, 2020. This transaction is exempt under Rule 16b-3(c). In accordance with the ESPP, these shares were purchased based on 85% of the closing price of the issuer's common stock on February 28, 2020. The reporting person is voluntarily reporting the acquisition of shares of the issuer's common stock pursuant to the ESPP for the ESPP purchase period of September 1, 2020 through February 28, 2021. This transaction is exempt under Rule 16b-3(c). In accordance with the ESPP, these shares were purchased based on 85% of the closing price of the issuer's common stock on September 1, 2020. /s/ Margaret Siegel as Attorney-in-Fact 2021-03-08