Seattle Genetics Update on SGN-40 Clinical Program

Seattle Genetics, Inc. today reported SGN-40 has shown evidence of biological activity in multiple myeloma, and the company has modified the dose and schedule of SGN-40 administration in the ongoing phase I clinical trials to minimize first dose effects that are potentially attributable to cytokine release.

In our SGN-40 clinical trials, we have seen preliminary indications of activity, including decreasing serum M-protein, urine protein and B-cell levels during treatment of several patients with multiple myeloma."

SGN-40 Phase I Clinical Trials

SGN-40 is a humanized monoclonal antibody that targets the CD40 antigen, which is expressed on most B-cell lineage hematologic malignancies, including multiple myeloma, non-Hodgkin's lymphoma and chronic lymphocytic leukemia. Seattle Genetics is conducting open-label, multi-dose, single-arm phase I studies designed to evaluate the safety, antitumor activity and pharmacokinetic profile of escalating doses of SGN-40 in patients with relapsed or refractory multiple myeloma or non-Hodgkin's lymphoma.

In the multiple myeloma study, 16 patients have been treated with SGN-40 at dose levels of 0.5, 1, 2 or 4 mg/kg. Patients were heavily pretreated with a median of 5.5 prior therapies, median time from initial diagnosis of 6.5 years and median age of 60 years. Repeated infusions of SGN-40 at doses of 0.5, 1 and 2 mg/kg were well tolerated. At 4 mg/kg, two of three patients experienced grade 3 headaches and were diagnosed with aseptic meningitis, from which both patients fully recovered. Seattle Genetics has amended the original protocol, including dose and schedule modifications, to attenuate potential cytokine release following the first infusion. Several patients demonstrated disease stabilization and decreasing M-protein in the blood and urine during treatment with SGN-40. The study is open for accrual and continued dose escalation.