Enrollment in phase II clinical trial of brentuximab vedotin for ALCL completed

Seattle Genetics, Inc.May 24 2010

Seattle Genetics, Inc. (Nasdaq: SGEN) and Millennium: The Takeda Oncology Company, a wholly owned subsidiary of Takeda Pharmaceutical Company Limited (TSE:4502), today announced that they have completed enrollment of a phase II clinical trial of brentuximab vedotin (SGN-35) for relapsed or refractory systemic anaplastic large cell lymphoma (ALCL). Brentuximab vedotin is an antibody-drug conjugate (ADC) targeted to CD30, which is highly expressed on ALCL cells.

“Brentuximab vedotin has the potential to provide an improvement in patient care, which is our primary goal, and is another step toward global oncology leadership for Millennium.”

"This phase II trial enrolled in less than a year, driven by strong interest among clinical investigators and the ALCL patient community," said Thomas C. Reynolds, M.D., Ph.D., Chief Medical Officer of Seattle Genetics. "We anticipate preliminary data from this trial will be available in the second half of 2010, which will guide the next steps towards our goal of bringing this promising ADC to ALCL patients. We believe that systemic ALCL may offer an additional registration pathway for brentuximab vedotin."

"The quick rate of enrollment in this trial attests to the high unmet need for innovative new therapies for patients with ALCL," said Nancy Simonian, M.D., Chief Medical Officer of Millennium. "Brentuximab vedotin has the potential to provide an improvement in patient care, which is our primary goal, and is another step toward global oncology leadership for Millennium."

The phase II trial, which was initiated in June 2009, is a single-agent, single-arm study evaluating 55 patients with relapsed or refractory systemic ALCL. Patients receive 1.8 milligrams per kilogram of brentuximab vedotin every three weeks for up to approximately one year. The primary endpoint of the study is objective response rate determined by independent review. Secondary endpoints include duration of response, progression-free survival, overall survival and tolerability.

Of seven systemic ALCL patients treated with brentuximab vedotin in phase I clinical trials, six (86 percent) achieved a complete remission. Brentuximab vedotin was generally well-tolerated in these studies. The majority of adverse events were Grade 1 and 2, with the most common being fatigue, fever, peripheral neuropathy, diarrhea and nausea.