Seattle Genetics, Inc. (NASDAQ:SGEN) announced today that John A. Orwin has been appointed to the company's Board of Directors. Mr. Orwin is a biotechnology and pharmaceutical industry veteran with nearly 25 years of experience, including senior leadership positions in many commercial oncology organizations. He currently serves as Chief Executive Officer of Relypsa, a clinical-stage pharmaceutical company.

"John's deep background in sales and marketing operations, as well as his experience in executive leadership positions at public biopharmaceutical companies will provide a strong addition to our Board," said Clay B. Siegall, Ph.D., President and Chief Executive Officer of Seattle Genetics. "I look forward to his contributions as we continue to deliver on Seattle Genetics' strategic priorities, including making ADCETRIS® (brentuximab vedotin) available to patients in its approved indications, broadly evaluating ADCETRIS across a range of CD30-positive malignancies and advancing our pipeline of other antibody-drug conjugates (ADCs)."

Mr. Orwin commented, "Seattle Genetics has delivered exceptionally well on the commercialization of ADCETRIS following its U.S. approval in 2011, and through the significant ongoing clinical development activities to broaden its labeled indications. In addition, under the collaboration with Takeda, ADCETRIS has become an important global brand. I am pleased to be joining the Board and look forward to working with the team to deliver on its goal of improving the lives of people with cancer."

John Orwin has served as Chief Executive Officer of Relypsa, Inc. since June 2013. Prior to Relypsa, he was at Affymax, serving most recently as Chief Executive Officer and a member of the Board of Directors. Previously, Mr. Orwin was Vice President and then Senior Vice President of the BioOncology Business Unit at Genentech (now a member of the Roche Group), where he was responsible for all marketing, sales, business unit operations and pipeline brand management for Genentech's oncology portfolio in the United States. He has also held senior marketing and sales positions at Johnson & Johnson, Alza Pharmaceuticals, Sangstat Medical Corporation, Rhone-Poulenc Rorer Pharmaceuticals and Schering-Plough Corporation. Mr. Orwin received an M.B.A. from New York University and a B.A. from Rutgers University.

About Seattle Genetics

Seattle Genetics is a biotechnology company focused on the development and commercialization of innovative antibody-based therapies for the treatment of cancer. Seattle Genetics is leading the field in developing antibody-drug conjugates (ADCs), a technology designed to harness the targeting ability of antibodies to deliver cell-killing agents directly to cancer cells. The company's lead product, ADCETRIS® (brentuximab vedotin), is an ADC that, in collaboration with Takeda Pharmaceutical Company Limited, has been approved for two indications in more than 35 countries, including the U.S., Canada and members of the European Union. Additionally, ADCETRIS is being evaluated broadly in more than 30 ongoing clinical trials. Seattle Genetics is also advancing a robust pipeline of clinical-stage ADC programs, including SGN-CD19A, SGN-CD33A, SGN-LIV1A, ASG-22ME and ASG-15ME. Seattle Genetics has collaborations for its ADC technology with a number of leading biotechnology and pharmaceutical companies, including AbbVie, Agensys (an affiliate of Astellas), Bayer, Genentech, GlaxoSmithKline and Pfizer. More information can be found at www.seattlegenetics.com.

Certain of the statements made in this press release are forward looking, such as those, among others, relating to the company's plans for clinical trials with ADCETRIS and other programs. Actual results or developments may differ materially from those projected or implied in these forward-looking statements. Factors that may cause such a difference include, among others, that adverse events adversely affect the ability to successfully conduct planned clinical trials. More information about the risks and uncertainties faced by Seattle Genetics is contained in the company's quarterly report on Form 10-Q for the quarter ended September 30, 2013, filed with the Securities and Exchange Commission. Seattle Genetics disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.

Seattle Genetics, Inc.
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