Seattle Genetics, Inc. announced that the US Food and Drug Administration (FDA) has accepted for filing two Biologics License Applications (BLAs) for brentuximab vedotin, including one for the treatment of patients with relapsed or refractory Hodgkin lymphoma and one for the treatment of patients with relapsed or refractory systemic Anaplastic Large Cell Lymphoma (ALCL).

The FDA administratively separated the original BLA submission and will act individually on the application for each indication. In addition, the FDA has granted a six-month priority review of both applications, and has established an action date of August 30, 2011 under the Prescription Drug User Fee Act (PDUFA).

Priority review designation is assigned to drugs that, if approved, would address an unmet medical need for a serious or life-threatening condition. Brentuximab vedotin is an Antibody-Drug Conjugate (ADC) directed to CD30, a defining marker of Hodgkin lymphoma and ALCL.

“These filings and priority review designations are an important step forward in our effort to bring brentuximab vedotin to the many relapsed and refractory Hodgkin lymphoma and systemic ALCL patients in need,” said Clay B Siegall, PhD, president and CEO of Seattle Genetics. “We look forward to continued interactions with the FDA as they review our brentuximab vedotin BLAs.”

Seattle Genetics announced on February 28, 2011 that it had submitted a BLA for brentuximab vedotin based on results from both a pivotal trial in relapsed or refractory Hodgkin lymphoma and a phase II trial in relapsed or refractory systemic ALCL that were presented at the American Society of Haematology (ASH) Annual Meeting in December 2010. The pivotal trial in Hodgkin lymphoma was conducted under a Special Protocol Assessment (SPA) with the FDA. Brentuximab vedotin has been granted orphan drug designation by the FDA for the treatment of Hodgkin lymphoma and ALCL.

Brentuximab vedotin is an ADC comprising an anti-CD30 monoclonal antibody attached by a protease-cleavable linker to a potent, synthetic drug, Mono-Methyl Auristatin E (MMAE) utilizing Seattle Genetics' proprietary technology. The ADC employs a novel linker system that is designed to be stable in the bloodstream but to release MMAE upon internalization into CD30-expressing tumour cells. This approach is intended to spare non-targeted cells, which may help minimize the potential toxic effects of traditional chemotherapy while allowing for the selective targeting of CD30-expressing cancer cells, thus potentially enhancing the anti-tumour activity.

Seattle Genetics is developing brentuximab vedotin 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 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 Takeda will be solely responsible for development costs.

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.

According to the American Cancer Society, approximately 8,500 cases of Hodgkin lymphoma were diagnosed in the United States during 2010 and more than 1,300 people were expected to die from the disease. Although front-line combination chemotherapy can result in durable response rates, up to 30 percent of these patients relapse or are refractory to front-line treatment and have few therapeutic options beyond autologous stem cell transplant.

ALCL is an aggressive type of T-cell non-Hodgkin lymphoma that highly expresses CD30. In the United States, approximately 2,000 systemic ALCL patients are diagnosed annually. Although front-line combination chemotherapy can result in durable remissions, approximately 50 percent of ALCL patients relapse or are refractory to front-line treatment and have few therapeutic options.

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.