exhibit 1. 1 adaptimmune therapeutics plc ( a public limited company organized under the laws of england and wales ) 7, 000, 000 american depositary shares representing an aggregate of 42, 000, 000 ordinary shares purchase agreement dated : april 5, 2017 adaptimmune therapeutics plc ( a public limited company organized under the laws of england and wales ) 7, 000, 000 american depositary shares representing an aggregate of 42, 000, 000 ordinary shares purchase agreement april 5, 2017 matrix capital management master fund, lp 1000 winter street suite 4500 waltham, ma 02451 ladies and gentlemen : adaptimmune therapeutics plc, a public limited company organized under the laws of england and wales ( the “ company ” ), confirms its agreement with matrix capital management master fund, lp ( the “ purchaser ” ), with respect to the issuance and sale by the company and the purchase by the purchaser of 7, 000, 000 american depositary shares of the company ( “ adss ” ), each ads representing 6 new ordinary shares, par value £0. 001 per share, of the company ( “ ordinary shares ” ). the new ordinary shares represented by the adss are herein called the “ shares. ” the adss will be evidenced by american depositary receipts ( the “ adrs ” ) to be issued pursuant to a deposit agreement dated may 11, 2015 by and among the company, citibank, n. a., as depositary ( the “ depositary ” ), and the holders from time to time of the adrs evidencing adss issued thereunder ( the “ deposit agreement ” ). the company has filed with the securities and exchange commission ( the “ commission ” ) a shelf registration statement on form s - 3 ( no. 333 - 212713 ), covering the public offering and sale of certain securities, including the shares, under the securities act of 1933, as amended ( the “ 1933 act ” ), and the rules and regulations promulgated thereunder ( the “ 1933 act regulations ” ), which shelf registration statement has been declared effective by the commission. such registration statement, as of any time, means such registration statement as amended by any post - effective amendments thereto to such time, including the exhibits and any schedules thereto at such time, the documents incorporated by reference therein at such time pursuant to item 12 of form s - 3 under the 1933 act and