-AETHERA trial designed to support full approval in the United States and Europe
-Data from ongoing pivotal trial to be reported in second half of 2010 and provide basis for NDA and MAA submissions in the first half of 2011

Bothell, WA, USA; Cambridge, MA, USA; and Osaka, Japan | April 8, 2010 | Seattle Genetics, Inc. (Nasdaq: SGEN), Takeda Pharmaceutical Company Limited (TSE: 4502) and its wholly owned subsidiary Millennium: The Takeda Oncology Company today announced the initiation of a phase III clinical trial of brentuximab vedotin (SGN-35) for post-transplant Hodgkin lymphoma patients. Brentuximab vedotin is an antibody-drug conjugate (ADC) targeted to CD30, which is expressed on malignant Hodgkin lymphoma cells. The phase III trial, also known as AETHERA, will evaluate brentuximab vedotin versus placebo for the treatment of patients at high risk of residual Hodgkin lymphoma following autologous stem cell transplant (ASCT).

“Our initial approval strategy for brentuximab vedotin is based on our ongoing pivotal trial in relapsed and refractory Hodgkin lymphoma, from which data are expected in the second half of 2010. The pivotal trial is designed to form the basis for registrational filings with the U.S. Food and Drug Administration (FDA) and European Medicines Agency (EMA) during the first half of 2011 under the accelerated approval and conditional authorization regulations respectively,” said Thomas C. Reynolds, M.D., Ph.D., Chief Medical Officer of Seattle Genetics. “The AETHERA trial is part of our broader development strategy and is designed to fulfill regulatory requirements for full approval in the United States and Europe. In addition, this trial will provide data on the use of brentuximab vedotin earlier in Hodgkin lymphoma therapy as part of an integrated second-line regimen with ASCT.”

“Brentuximab vedotin has the potential to address a large unmet medical need in the patient community. By utilizing Seattle Genetics’ ADC technology, the molecule selectively targets CD30, potentially making it the first new drug in more than a decade for patients with relapsed Hodgkin lymphoma,” said Nancy Simonian, M.D., Chief Medical Officer of Millennium. “The initiation of this phase III trial is aimed to support the ongoing pivotal trial of brentuximab vedotin and further enables the Takeda Group to move toward its goal of global oncology leadership.”

The AETHERA trial is a randomized, double-blind, placebo-controlled phase III study comparing progression-free survival in approximately 325 post-ASCT patients receiving brentuximab vedotin to those receiving placebo. Patients must be at high risk for residual Hodgkin lymphoma, defined as those with a history of refractory Hodgkin lymphoma, those who relapse or progress within one year from receiving front-line chemotherapy and/or those who have disease outside of the lymph nodes at the time of pre-ASCT relapse. Secondary endpoints of the trial include overall survival, safety and tolerability. Patients will receive brentuximab vedotin every three weeks for up to approximately one year. This international multi-center trial will be conducted in the United States, Europe and Russia.

Seattle Genetics is developing brentuximab vedotin in collaboration with Millennium, under which Seattle Genetics has U.S. and Canadian commercialization rights and the Takeda Group has rights to commercialize brentuximab vedotin in the rest of the world. Seattle Genetics and the Takeda Group are funding joint development costs for brentuximab vedotin on a 50:50 basis, except in Japan where the Takeda Group will be solely responsible for development costs.

Under the collaboration, Seattle Genetics and Millennium are conducting a pivotal trial of brentuximab vedotin for relapsed and refractory Hodgkin lymphoma under a Special Protocol Assessment (SPA) with the FDA, and top-line data are expected in the second half of 2010. The pivotal trial also received EU Centralized Scientific Advice from the EMA. The pivotal trial is designed to form the basis for registrational filings with the FDA and EMA under the accelerated approval and conditional authorization regulations. These regulations provide a mechanism for making promising products for life-threatening diseases commercially available on the basis of preliminary evidence prior to formal demonstration of patient benefit.

In addition, the companies are conducting a phase II trial for relapsed and refractory systemic anaplastic large cell lymphoma, a phase II retreatment trial for relapsed patients who previously responded to brentuximab vedotin therapy, and a phase I combination trial for front-line Hodgkin lymphoma.

About Hodgkin Lymphoma

Lymphoma is a general term for a group of cancers that originate in the lymphatic system. There are two major categories of lymphoma: Hodgkin lymphoma and non-Hodgkin lymphoma. Hodgkin lymphoma is distinguished pathologically from other types of lymphoma by the presence of one characteristic type of cell, known as the Reed-Sternberg cell. A defining attribute of the Reed-Sternberg cell is its expression of the CD30 antigen. According to the American Cancer Society, approximately 8,500 cases of Hodgkin lymphoma were diagnosed in the United States during 2009.

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’s lead product candidate, brentuximab vedotin, is in a pivotal trial under an SPA with the FDA. Brentuximab vedotin is being developed in collaboration with Millennium: The Takeda Oncology Company. In addition, Seattle Genetics has four other product candidates in ongoing clinical trials: lintuzumab (SGN-33), dacetuzumab (SGN-40), SGN-70 and SGN-75. Seattle Genetics has collaborations for its ADC technology with a number of leading biotechnology and pharmaceutical companies, including Bayer, Celldex Therapeutics, Daiichi Sankyo, Genentech, GlaxoSmithKline, MedImmune, a subsidiary of AstraZeneca, Millennium: The Takeda Oncology Company and Progenics, as well as an ADC co-development agreement with Agensys, an affiliate of Astellas. More information can be found at www.seattlegenetics.com.

About Takeda Pharmaceutical Company Limited

Located in Osaka, Japan, Takeda is a research-based global company with its main focus on pharmaceuticals. As the largest pharmaceutical company in Japan and one of the global leaders of the industry, Takeda is committed to striving toward better health for individuals and progress in medicine by developing superior pharmaceutical products. Additional information about Takeda is available through its corporate website, www.takeda.com

About Millennium

Millennium: The Takeda Oncology Company, a leading biopharmaceutical company based in Cambridge, Mass., markets a first-in-class proteasome inhibitor, and has a robust clinical development pipeline of product candidates. Millennium Pharmaceuticals, Inc. was acquired by Takeda Pharmaceutical Company Ltd. in May, 2008. The Company’s research, development and commercialization activities are focused in oncology. Additional information about Millennium is available through its website, www.millennium.com.

For Seattle Genetics: Certain of the statements made in this press release are forward looking, such as those, among others, relating to the submission for approval of and eventual approval of brentuximab vedotin. 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 the inability to show statistically significant benefit in our pivotal trial or the phase III trial, the incidence of adverse events as brentuximab vedotin advances in these clinical trials or delays resulting from requests for additional information or clinical evidence from the FDA or EMA. More information about the risks and uncertainties faced by Seattle Genetics is contained in the company’s annual report on Form 10-K for the year ended December 31, 2009 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: Takeda Pharmaceutical Company Limited