X0306 4 2019-08-30 0 0001060736 SEATTLE GENETICS INC /WA SGEN 0001241357 LIU JEAN I 21823 30TH DRIVE SE BOTHELL WA 98021 0 1 0 0 See Remarks Common Stock 2019-08-30 4 A 0 18995 0.00 A 79899 D Common Stock 2019-09-03 4 S 0 1779 0.00 D 78120 D Incentive Stock Options (right to buy) 72.64 2019-08-30 4 A 0 1333 0.00 A 2029-08-30 Common Stock 1333 1333 D Non. Qualified Stock Option (right to buy) 72.64 2019-08-30 4 A 0 43786 0.00 A 2029-08-30 Common Stock 43786 43786 D These shares represent restricted stock units and will be settled in common stock upon vesting. Shares shall vest at a rate of 25% on each anniversary of the grant date until all shares are fully vested four years from the grant date. Amount of securities beneficially owned following reported transactions includes restricted stock units subject to vesting. Shares sold pursuant to a 10b5-1 arrangement to satisfy tax obligations arising out of the vesting of previously granted restricted stock units. Options shall vest at a rate of 25% one year from grant date and monthly thereafter until all shares are fully vested four years from grant date. GC/EVP, Leg Affairs 8075 - Legal Affairs Jean Liu 2019-09-04