Seattle Genetics Receives FDA Fast Track Designation for SGN-35 for the Treatment of Hodgkin Lymphoma

Seattle Genetics Receives FDA Fast Track Designation for SGN-35 for the Treatment of Hodgkin Lymphoma

BOTHELL, Wash.--(BUSINESS WIRE)--Mar. 30, 2009-- Seattle Genetics, Inc. today announced that the U.S. Food and Drug Administration (FDA) has granted fast track designation to SGN-35 for the treatment of Hodgkin lymphoma. SGN-35, an antibody-drug conjugate (ADC), is in an ongoing pivotal trial under a Special Protocol Assessment (SPA) from the FDA for relapsed or refractory Hodgkin lymphoma.

"Receiving fast track designation is another important component of our regulatory strategy for SGN-35, and a key step for this program," said Clay B. Siegall, Ph.D., President and Chief Executive Officer of Seattle Genetics. "With our pivotal trial underway, we expect data in 2011. Our goal remains to submit a new drug application (NDA) in 2011 with potential commercial launch in 2012."

The fast track program is designed to facilitate the development and expedite the review of new drugs that are intended to treat serious or life-threatening conditions and that demonstrate the potential to address unmet medical needs. Fast track designated drugs ordinarily qualify for priority review, thereby expediting the FDA review process. In addition, the designation allows the SGN-35 NDA to be considered for submission on a rolling basis, allowing the FDA to review sections of the NDA as they are completed.

In February 2009, Seattle Genetics initiated a pivotal trial of SGN-35. The study is evaluating efficacy and safety of single-agent SGN-35 in 100 patients with relapsed or refractory Hodgkin lymphoma. The primary endpoint of the trial is objective response rate assessed by an independent radiographic facility. Secondary endpoints include duration of response, progression-free survival, overall survival and tolerability. The company plans to enroll patients at more than 30 sites in the United States, Canada and Europe. In January 2009, the company received an SPA for the pivotal trial, which is an agreement with the FDA regarding the trial design necessary to support an efficacy claim in an NDA. SGN-35 has received orphan drug designation in the United States and Europe for both Hodgkin lymphoma and anaplastic large cell lymphoma (ALCL).

Seattle Genetics plans to initiate a phase II study of single-agent SGN-35 in approximately 55 patients with relapsed or refractory systemic ALCL. In addition, the company plans to report data from an ongoing weekly dosing phase I clinical trial of SGN-35 during an oral presentation at the American Society of Clinical Oncology annual meeting to be held May 29 to June 2, 2009.

About SGN-35

SGN-35 is an ADC comprising an anti-CD30 antibody attached by an enzyme cleavable linker to a potent, synthetic drug payload, monomethyl auristatin E (MMAE), using Seattle Genetics' proprietary technology. The ADC is designed to be stable in the bloodstream, but to release MMAE upon internalization into CD30-expressing tumor cells, resulting in a targeted cell-killing effect.

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 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. Based on market research, Seattle Genetics believes that there are several thousand newly relapsed or refractory lymphoma patients in the United States each year who would be potentially eligible for treatment with SGN-35, and that the U.S. prevalence population of these patients is approximately 10,000 individuals.

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, SGN-35, is in a pivotal trial under an SPA with the FDA. SGN-35 is empowered by Seattle Genetics' proprietary ADC technology comprising highly potent synthetic drugs and stable linkers for attaching the drugs to monoclonal antibodies. In addition, Seattle Genetics has three other product candidates in ongoing clinical trials: dacetuzumab (SGN-40), lintuzumab (SGN-33) and SGN-70. Dacetuzumab is being developed under a worldwide collaboration with Genentech. Seattle Genetics has collaborations for its ADC technology with a number of leading biotechnology and pharmaceutical companies, including Genentech, Bayer, CuraGen, Progenics, Daiichi Sankyo and MedImmune, a subsidiary of AstraZeneca, as well as an ADC co-development agreement with Agensys, a subsidiary of Astellas Pharma. 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 potential therapeutic benefit, regulatory pathway, timelines and market potential of SGN-35. 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 the company may experience delays in the initiation and/or completion of the clinical trials of SGN-35 in Hodgkin lymphoma and ALCL, whether caused by competition, adverse events, patient enrollment rates, regulatory issues or other factors; that the clinical trials, including the pivotal clinical trial for relapsed or refractory Hodgkin lymphoma, may not demonstrate that SGN-35 is both safe and effective; that data from our phase I clinical trials of SGN-35 may not necessarily be indicative of the subsequent clinical trial results, including our pivotal clinical trial results; that fast track designation and priority review may not result in earlier approval; and that the safety and/or efficacy results of these trials, including the SGN-35 pivotal clinical trial for relapsed or refractory Hodgkin lymphoma, will not support an application for marketing approval in the United States or any other country. More information about the risks and uncertainties faced by Seattle Genetics is contained in the company's filings 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.