Seattle Genetics Inc. announced interim results from a phase I clinical trial evaluating ASG-5ME for the treatment of metastatic pancreatic ductal adenocarcinoma (PDA) at the American Society of Clinical Oncology (ASCO) 2013 Gastrointestinal Cancers Symposium being held January 24-26, 2013 in San Francisco, CA. ASG-5ME is an antibody-drug conjugate (ADC) targeting the SLC44A4 antigen and is being co-developed by Seattle Genetics and Agensys Inc. The phase I data from the ASG-5ME clinical trial in advanced pancreatic cancer identified the maximum tolerated dose (MTD) for weekly administration, demonstrated tolerability and provided preliminary evidence for antitumor activity. ADCs are monoclonal antibodies that are designed to deliver cytotoxic agents selectively to tumor cells.

This approach is designed to spare non-targeted cells and thus reduce many of the toxic effects of traditional chemotherapy while enhancing antitumor activity. With over a decade of experience and knowledge in ADC innovation, Seattle Genetics has developed proprietary technology employing synthetic cytotoxic agents, such as monomethyl auristatin E (MMAE), and stable linker systems that attach these cytotoxic agents to the antibody. Key findings included: The MTD was identified as 1.2 mg/kg weekly.

Of the 35 patients who participated in the trial at the time of analysis, 18 were treated at the MTD. Best response for the 18 patients treated at 1.2 mg/kg weekly included one patient (6%) who achieved a partial response, six patients (33%) with stable disease and four patients (22%) who had progressive disease. Seven patients (39 percent) were not evaluable for response.

The most common adverse events occurring in patients at the MTD included fatigue (50.0%), vomiting (44.4%), decreased appetite (38.9%), abdominal pain (33.3%) and nausea (33.3%).