BOTHELL, Wash., Apr 05, 2011 (BUSINESS WIRE) --

Seattle Genetics, Inc. (Nasdaq: SGEN) today announced that research related to its antibody-drug conjugate (ADC) technology was presented at the 102^nd Annual Meeting of the American Association for Cancer Research (AACR) being held in Orlando, FL. The presentations highlighted advances being made by the company with its ADC technology and preclinical research on its ADC pipeline, including brentuximab vedotin (SGN-35), SGN-75 and SGN-19A.

"These presentations demonstrate our continued leadership in the field of ADCs, including using the technology to extend our pipeline of preclinical product candidates, exploring ADCs in combination with standard therapies, and measuring their pharmacodynamic effects," said Jonathan Drachman, M.D., Senior Vice President, Research and Translational Medicine at Seattle Genetics. "We also illustrate how to refine properties of future drug-linkers and how to evaluate this new class of molecules in clinical trials. This research reflects our enthusiasm and continued belief that ADCs are a significant, emerging class of cancer therapeutics."

ADCs are monoclonal antibodies that selectively deliver potent anti-cancer agents to tumor cells. With over a decade of experience and knowledge in ADC innovation, Seattle Genetics has developed proprietary technology employing synthetic, potent cell-killing agents called auristatins (such as MMAE and MMAF) and stable linker systems that attach auristatin to the antibody. Seattle Genetics' novel linker systems are designed to be stable in the bloodstream and release the potent cell-killing agent once inside targeted cancer cells. This approach is intended to spare non-malignant cells and reduce many of the toxic effects of traditional chemotherapy while enhancing antitumor activity.

Seattle Genetics' presentations at AACR demonstrated the following:

• Auristatin-based ADCs, including brentuximab vedotin and SGN-75, have synergistic activity when combined with mTOR inhibitors such as sirolimus and everolimus in several solid tumor and hematologic malignancy tumor models. (Abstract #1789)
• Methods have been developed to assess the effect of SGN-75 on CD70-positive cells, including in blood samples from a subset of patients in an ongoing phase I clinical trial. These methods may be appropriate for measuring pharmacodynamic effects. (Abstract #1284)
• SGN-19A, which comprises an anti-CD19 monoclonal antibody linked to MMAF, effectively targets CD19 and induces antitumor activity in models of non-Hodgkin lymphoma and acute lymphoblastic leukemia. SGN-19A is a future investigational new drug candidate. (Abstract #625)
• LIV-1 is a promising new target antigen, expressed at high levels on breast and prostate cancers. An anti-LIV-1 ADC demonstrates antitumor activity in multiple preclinical models. (Abstract #3620)
• A novel screening method was developed to identify drug-linkers that are metabolized differently in tumors compared with normal tissue. These advances could further enhance the specificity of ADCs on cancer cells. (Abstract #2831)

About Seattle Genetics

Seattle Genetics is a clinical-stage biotechnology company focused on the development and commercialization of monoclonal antibody-based therapies for the treatment of cancer and autoimmune disease. The company submitted a Biologics License Application to the U.S. Food and Drug Administration for its lead product candidate, brentuximab vedotin, for the treatment of relapsed or refractory Hodgkin lymphoma and systemic anaplastic large cell lymphoma in February 2011. Brentuximab vedotin is being developed in collaboration with Millennium: The Takeda Oncology Company. In addition, Seattle Genetics has four other clinical-stage programs: SGN-75, ASG-5ME, dacetuzumab (SGN-40) and SGN-70. Seattle Genetics has collaborations for its ADC technology with a number of leading biotechnology and pharmaceutical companies, including Abbott, Bayer, Celldex Therapeutics, Daiichi Sankyo, Genentech, GlaxoSmithKline, Millennium, Pfizer and Progenics, as well as ADC co-development agreements with Agensys, an affiliate of Astellas, and Genmab. 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 therapeutic potential of Seattle Genetics' product candidates and its ADC technology. 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 risks related to failure of our or our collaborators' product candidates incorporating ADC technologies to show sufficient safety and efficacy to advance in clinical trials or obtain regulatory approval. More information about the risks and uncertainties faced by Seattle Genetics is contained in the company's 10-K for the year ended December 31, 2010 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.

SOURCE: Seattle Genetics, Inc.

Seattle Genetics, Inc.
Peggy Pinkston, 425-527-4160
ppinkston@seagen.com