Seattle Genetics Reports Data from a Weekly Dosing Phase I Clinical Trial of SGN-35 in Lymphoma
News Jun 02, 2009
Seattle Genetics, Inc. has reported data from an ongoing phase I weekly-dosing clinical trial of SGN-35, an antibody-drug conjugate (ADC), including multiple complete and partial responses in patients with relapsed or refractory Hodgkin lymphoma or systemic anaplastic large cell lymphoma (ALCL).
The data are being presented during a Clinical Science Symposium at the American Society of Clinical Oncology (ASCO) Annual Meeting being held in Orlando, Florida. In addition, data on dacetuzumab (SGN-40) are being presented in a poster session describing a diagnostic gene signature that may identify lymphoma patients who are more likely to respond to dacetuzumab therapy.
In the phase I weekly-dosing trial of SGN-35, out of 27 patients who were evaluable for response, 13 patients achieved objective responses, including 10 complete responses and 3 partial responses. Eleven patients had stable disease and three patients had progressive disease. The median duration of response is at least 16 weeks, with 12 responses still ongoing.
Among 20 evaluable patients treated at doses of 0.8 milligrams per kilogram (mg/kg) and higher, 60 percent achieved an objective response, including 50 percent with complete responses. Across all dose levels, 81 percent of patients achieved tumor reductions. SGN-35 was generally well tolerated. The majority of adverse events were Grade 1 and 2, with the most common being nausea, fatigue, peripheral neuropathy and neutropenia.
“Data from this second phase I clinical trial of SGN-35 reaffirm the objective response rate and tolerability profile observed in the first phase I clinical trial, providing further clinical support for our aggressive development plans, including our ongoing pivotal trial in Hodgkin lymphoma,” said Clay B. Siegall, Ph.D., President and Chief Executive Officer of Seattle Genetics.
“We are continuing patient treatment and follow-up on the weekly-dosing trial, including assessment of tolerability, response rate and durability of responses. In addition, we are considering other clinical trials to further explore the weekly schedule to optimize administration of SGN-35.”
Seattle Genetics is advancing an ongoing pivotal trial of SGN-35 administered every three weeks for relapsed and refractory Hodgkin lymphoma and a planned phase II trial for systemic anaplastic large cell lymphoma. The pivotal trial is being conducted under a Special Protocol Assessment (SPA) with the U.S. Food and Drug Administration (FDA).
SGN-35 is an ADC comprising an anti-CD30 antibody attached by an enzyme-cleavable linker to a potent, synthetic drug payload, monomethyl auristatin E (MMAE), using Seattle Genetics’ proprietary technology. The ADC is designed to be stable in the bloodstream, but to release MMAE upon internalization into CD30-expressing tumor cells, resulting in targeted cell-killing.
“There are limited available treatment options for patients with relapsed and refractory Hodgkin lymphoma and systemic ALCL who have either have failed or are not eligible for stem cell transplant,” said Nancy Bartlett, M.D., Koman Chair in Medical Oncology at Washington University School of Medicine at Siteman Cancer Center, and presenting investigator of the phase I study. “These phase I data suggest that SGN-35 could become an important new therapy for these patients.”