X0306 4 2020-06-09 0 0001621227 Adaptimmune Therapeutics PLC ADAP 0001553053 Alleva Lawrence M C/O ADAPTIMMUNE THERAPEUTICS PLC, 60 JUBILEE AVE, MILTON PARK ABINGDON X0 OX14 4RX UNITED KINGDOM 1 0 0 0 Ordinary Shares with a nominal value of GBP0.001 per share 2020-06-09 4 P 0 12900 1.89 A 12900 I Held by Trust Ordinary Shares with a nominal value of GBP0.001 per share 47280 I Held by Trust Ordinary Shares with a nominal value of GBP0.001 per share 70584 D The ordinary shares whose purchase is reported on this line are represented by American Depositary Shares ("ADS") and are held in the form of ADSs by the Lawrence M. Alleva Revocable Trust. Each ADS represents six ordinary shares of Adaptimmune Therapeutics plc. The 12,900 ordinary shares reported in Column 4 and Column 5 are represented by 2,150 ADSs. The price reported in Column 4 of $1.89 per ordinary share is derived from the purchase price paid on June 9, 2020 of $11.354 per ADS divided by six. The 47,280 ordinary shares reported in Column 5 are represented by 7,880 ADSs. These shares are held in the form of ADSs by the Lawrence M. Alleva Revocable Trust. The 70,584 ordinary shares reported in Column 5 are represented by 11,764 ADSs. These shares are held in the form of ADSs by Mr. Alleva. /s/ Lawrence M. Alleva 2020-06-11