Millennium, SGEN expand ADC collaboration

Seattle Genetics, Inc. (Nasdaq: SGEN) announced today that Millennium: The Takeda Oncology Company, a wholly owned subsidiary of Takeda Pharmaceutical Company Limited (TSE:4502), has paid an undisclosed fee to exercise an option to designate a second antigen target under the parties' existing antibody-drug conjugate (ADC) collaboration. Seattle Genetics entered into this collaboration with Millennium in April 2009, at which time Millennium obtained an exclusive ADC license to an initial antigen expressed on solid tumors as well as two options for exclusive licenses to additional targets.

"This expansion of our ADC collaboration demonstrates Millennium's continuing commitment to our ADC technology," stated Eric L. Dobmeier, Chief Business Officer of Seattle Genetics. "We currently have 10 ongoing ADC collaborations and have generated nearly $150 million from ADC licensing deals to date. In addition, there are 11 ADCs in clinical development utilizing Seattle Genetics' technology."

Under the terms of the ADC collaboration, Millennium is responsible for research, product development, manufacturing and commercialization of any ADC products resulting from the collaboration. Seattle Genetics is entitled to receive progress-dependent milestone payments and mid-single digit royalties from Millennium on worldwide net sales of any resulting ADC products. Seattle Genetics also receives supply and annual maintenance fees as well as research support payments for assistance provided to Millennium under the collaboration.

ADCs are monoclonal antibodies that are designed to selectively deliver 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, 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-targeted cells and thus may reduce many of the toxic effects of traditional chemotherapy while enhancing antitumor activity.

In addition to the companies' ADC technology collaboration, Seattle Genetics and Millennium are jointly developing brentuximab vedotin, an ADC directed to CD30. Seattle Genetics submitted a Biologics License Application to the U.S. Food and Drug Administration for brentuximab vedotin for the treatment of relapsed or refractory Hodgkin lymphoma and relapsed or refractory systemic anaplastic large cell lymphoma in February 2011. Under the terms of the collaboration agreement, Seattle Genetics has U.S. and Canadian commercialization rights and Takeda has rights to commercialize brentuximab vedotin in the rest of the world.