X0306 4/A 2015-08-25 2016-08-22 0 0001060736 SEATTLE GENETICS INC /WA SGEN 0001633639 Cline Darren S 21823 30TH DRIVE SE BOTHELL WA 98021 0 1 0 0 EVP, Commercial Common Stock 40973 D Incentive Stock Option Right to Buy 39.15 2015-08-25 4 A 0 2220 0.00 A 2025-08-25 Common Stock 2220 2220 D Amount of securities beneficially owned following reported transactions includes restricted stock units subject to vesting. Due to administrative error, on August 22, 2016, a Form 4 that had already been filed on August 25, 2015 was refiled (SEC Accession No. 0001203311-16-000118). This amendment to Form 4 is being filed solely to "withdraw" the mistakenly re-filed Form 4. One of the transactions reported in the August 22, 2016 Form 4 (an acquisition of 2,200 incentive stock options to purchase Common Stock) is being repeated in this amendment solely to be able to file this amendment with the SEC's EDGAR system. The Reporting Person's holdings as of the date of this Form 4/A filing are set forth in Table 1 above. The option shares shall vest at a rate of 25% on 08/25/2016 and monthly thereafter until all shares are fully vested four years from grant date. /s/ Darren S. Cline 2016-08-24