Summary of SEATTLE GENETICS INC /WA

Item 5.02. Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

On May 18, 2012, at the 2012 Annual Meeting of Stockholders (the "Annual Meeting") of Seattle Genetics, Inc. (the "Company"), the Company's stockholders approved the amendment and restatement of the Company's Amended and Restated 2007 Equity Incentive Plan (the "2007 Plan") to increase the number of shares of the Company's common stock authorized for issuance under the 2007 Plan by 4,000,000 shares and to effect certain other changes to the 2007 Plan as follows:

Х increasing the maximum aggregate number of shares the Company's common stock that may be issued under the 2007 Plan through incentive stock options to 16,500,000 shares;

Х clarifying that the prohibition in the 2007 Plan on repricing stock options without prior stockholder approval that applies to underwater awards also applies to stock appreciation rights and also prohibits the cancellation of such awards in exchange for cash or other stock awards under the 2007 Plan; and

Х extending the term of the 2007 Plan to May 18, 2022.

The amendment and restatement of the 2007 Plan (as so amended and restated, the "Restated 2007 Plan"), previously had been approved, subject to stockholder approval, by the Board of Directors of the Company. The Restated 2007 Plan became effective immediately upon stockholder approval at the Annual Meeting.

A more detailed summary of the material features of the Restated 2007 Plan is set forth in the Company's definitive proxy statement for the Annual Meeting filed with the Securities and Exchange Commission on April 13, 2012 (the "Proxy Statement"). That summary and the foregoing description is qualified in its entirety by reference to the text of the Restated 2007 Plan, which is attached as Appendix A to the Proxy Statement.

Item 5.07. Submission of Matters to a Vote of Security Holders.

At the Annual Meeting held on May 18, 2012, the Company's stockholders voted on the five proposals listed below. The final results for the votes regarding each proposal are set forth below. The proposals are described in detail in the Proxy Statement.

1. To elect the following three Class II directors to hold office until the Company's 2015 Annual Meeting of Stockholders.

                                   Votes            Votes           Broker
            Name                    For           Withheld        Non-Votes
            Clay B. Siegall       93,855,881         290,400       10,951,749
            Felix Baker           93,806,049         340,232       10,951,749
            Nancy A. Simonian     92,221,752       1,924,529       10,951,749

2. To approve the amendment and restatement of the Seattle Genetics, Inc. Amended and Restated 2007 Equity Incentive Plan to increase the aggregate number of shares of common stock authorized for issuance thereunder by 4,000,000 shares and to make certain other changes thereto as described in the Proxy Statement.

Votes For Votes Against Abstentions Broker Non-Votes 77,705,305 16,393,175 47,801 10,951,749

3. To ratify the appointment of PricewaterhouseCoopers LLP as the Company's independent registered public accounting firm for the fiscal year ending December 31, 2012.

Votes For Votes Against Abstentions Broker Non-Votes 104,882,944 147,499 67,587 -

4. To approve, on an advisory basis, the compensation of the Company's named executive officers as disclosed in the Proxy Statement.

Votes For Votes Against Abstentions Broker Non-Votes 92,796,708 1,280,041 69,532 10,951,749