Seattle Genetics, Inc. has initiated a phase I clinical trial of SGN-70, a humanized monoclonal antibody targeting CD70 that is being developed as an investigational therapy for autoimmune diseases. The trial will assess the safety, tolerability and pharmacokinetics of SGN-70 in healthy volunteers.

"CD70 targeted therapies have shown promise in multiple preclinical models by reducing autoimmune disease activity at well-tolerated doses," said Thomas C. Reynolds, M.D., Ph.D., chief medical officer of Seattle Genetics. "This clinical trial is designed to evaluate the safety and pharmacokinetics of SGN-70 in humans and to serve as a foundation for future clinical trials in patients with autoimmune disease."

The phase I study is a dose-escalation trial in which cohorts of healthy volunteers will receive single doses of SGN-70. The clinical trial will be conducted in Switzerland and is expected to accrue approximately 60 volunteers.

The CD70 antigen is highly expressed on activated T- and B-cells but not resting lymphocytes, and has been associated with a variety of autoimmune and inflammatory disorders. SGN-70 has been shown in preclinical models to selectively deplete CD70-positive lymphocytes and block the co-stimulation pathway between CD70 and its receptor, CD27. By specifically targeting the activated cells, SGN-70 may reduce the damaging effects of autoimmune disease without globally suppressing the immune system.

CD70 is also expressed on several types of cancer, including multiple myeloma, lymphoma, renal cell cancer, glioblastoma and several other solid tumours. In addition to SGN-70, Seattle Genetics is advancing SGN-75, an antibody-drug conjugate targeting CD70, for the treatment of cancer and expects to file an investigational new drug (IND) application in 2009.

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.