Seattle Genetics, Inc. announced that it has initiated a phase II clinical trial of Adcetris (brentuximab vedotin) for patients with relapsed or refractory CD30-positive Non-Hodgkin Lymphomas (NHL), including diffuse large B-cell lymphoma, peripheral T-cell lymphoma and other less common lymphoma subtypes. The trial is designed to assess the antitumor activity, duration of response and safety profile of Adcetris in these patients. Adcetris is an antibody-drug conjugate (ADC) directed to CD30. On August 19, 2011, the US Food and Drug Administration (FDA) granted accelerated approval of Adcetris for two indications.

“This clinical trial is part of our comprehensive development plan to broadly evaluate the potential of Adcetris in CD30-positive malignancies, building on the data we have generated in certain patients with Hodgkin lymphoma and systemic ALCL,” said Thomas C Reynolds, MD, PhD, chief medical officer of Seattle Genetics. “We believe the targeting ability of Adcetris to CD30 provides significant opportunities in selected lymphoma subtypes. This study and our other planned trials will further define the potential role of Adcetris in these patients.”

The primary endpoint of the phase II trial is to determine the anti-tumour activity of Adcetris as measured by objective response rate. In addition, the trial will characterize the relationship of CD30 expression with anti-tumour activity. Eligible patients must have relapsed or refractory CD30-positive non-Hodgkin lymphoma, other than cutaneous or systemic anaplastic large cell lymphoma (ALCL). The study is expected to enroll up to approximately 55 patients at multiple centres in the United States.

Adcetris (brentuximab vedotin) is an ADC comprising an anti-CD30 monoclonal antibody attached by a protease-cleavable linker to a microtubule disrupting agent, monomethyl auristatin E (MMAE), utilizing Seattle Genetics' proprietary technology. The ADC employs a linker system that is designed to be stable in the bloodstream but to release MMAE upon internalization into CD30-expressing tumour cells.

In addition to the NHL trial, Adcetris is being evaluated in a phase III clinical trial (the AETHERA trial) for patients at high risk of residual Hodgkin lymphoma following autologous stem cell transplant (ASCT), a phase II retreatment trial for relapsed patients who previously responded to Adcetris, a phase I trial in combination with multi-agent chemotherapy for front-line treatment of Hodgkin lymphoma and a phase I trial in combination with multi-agent chemotherapy for front-line treatment of systemic ALCL. A phase II trial in CD30-positive non-lymphoma malignancies is planned to begin during 2011.

Seattle Genetics is developing Adcetris in collaboration with Millennium: The Takeda Oncology Company. Under the terms of the collaboration agreement, Seattle Genetics has US and Canadian commercialization rights and the Takeda Group has rights to commercialize Adcetris in the rest of the world. Seattle Genetics and the Takeda Group are funding joint development costs for Adcetris on a 50:50 basis, except in Japan where the Takeda Group will be solely responsible for development costs.

Seattle Genetics is a biotechnology company focused on the development and commercialization of monoclonal antibody-based therapies for the treatment of cancer.