Seattle Genetics, Inc and Millennium: The Takeda Oncology Company, a wholly-owned subsidiary of Takeda Pharmaceutical Company Limited, announced positive top-line results from a phase-II clinical trial of single-agent brentuximab vedotin (SGN-35), an antibody-drug conjugate (ADC) targeted to CD30. The trial was conducted in 58 relapsed or refractory systemic anaplastic large cell lymphoma (ALCL) patients.

Eighty-six percent of patients in the trial achieved an objective response as assessed by an independent central review. Overall response rate, including both complete and partial remissions, is the primary endpoint of the study. The median duration of response has not yet been reached at a median follow up on study of approximately six months. The safety profile of brentuximab vedotin in this trial was generally consistent with prior clinical trial experience. More complete data from this ALCL trial as well as the pivotal trial of brentuximab vedotin in Hodgkin lymphoma (HL) will be presented in oral sessions at the American Society of Hematology (ASH) annual meeting, December 4 to 7, 2010, in Orlando, FL.

"Based on overall response rates of 86 percent in ALCL and 75 percent in HL with single-agent brentuximab vedotin, we intend to discuss regulatory next steps with the U.S. Food and Drug Administration (FDA) later this year with the goal of including both indications in our Biologics License Application (BLA) submission planned for the first half of 2011," said Clay B Siegall, president and chief executive officer of Seattle Genetics. "These remarkable data in relapsed or refractory patients highlight the broader opportunity for brentuximab vedotin in CD30-positive haematologic malignancies and reinforce our ongoing and planned clinical development activities. We believe that brentuximab vedotin represents the next step in the evolution of targeted therapy and could be the first in a new class of advanced generation ADCs."

"We are thrilled to report these impressive data in this highly refractory patient population with a significant unmet medical need," said Nancy Simonian, chief medical officer of Millennium. "The very high rate of objective responses observed with single-agent brentuximab vedotin in relapsed or refractory ALCL adds to the overall response rate and duration of response recently reported in relapsed or refractory HL. These data also provide further validation for a CD30-targeted ADC. We intend to discuss the path toward registration with regulatory agencies in Europe and the rest of the world as soon as possible."

Brentuximab vedotin is an ADC comprising an anti-CD30 monoclonal antibody attached by an enzyme cleavable linker to a potent, synthetic drug payload, monomethyl auristatin E (MMAE) utilizing Seattle Genetics' proprietary technology.

Seattle Genetics and Millennium are jointly developing brentuximab vedotin. Under the terms of the collaboration agreement, Seattle Genetics has US and Canadian commercialization rights and the Takeda Group has rights to commercialize brentuximab vedotin in the rest of the world.

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.