This study was designed to evaluate E7389 as a monotherapy in patients with refractory breast cancer. The primary endpoint of this trial was response rate, measured using the RECIST (Response Evaluation Criteria In Solid Tumors) criteria ?a group of standards used to measure responses to treatment in solid tumors.
Of the 65 evaluable patients, 10 partial responses were confirmed at the 4th cycle assessment. Twenty-one patients had stable disease (SD). In treatment-refractory patients with advanced breast cancer this preliminary response rate (15%) appears promising.
Based on the preliminary results of this study, the predominant serious side effect related to E7389 was neutropenia (low white blood cell counts). Other side effects were considered mild to moderate and included nausea, fatigue, dehydration, arthralgias, dyspnea and neuropathy. None of the patients discontinued the study due to hematological toxicity.
"The results from this study with E7389 appear promising, and clinical research on E7389 as a treatment for breast cancer is continuing," said Sandra Silberman, MD, PhD, Associate Vice President and Global Therapeutic Area Head, Oncology at Eisai Medical Research Inc. "E7389 is an example of Eisai's human health care (hhc) commitment to satisfy unmet medical needs of patients and their families. Eisai has targeted oncology/critical care as one of three key therapeutic areas of focus," she added.
Seventy-one women were enrolled in the 28-day cycle patient group. Preliminary efficacy data for 65 patients and safety data on 48 patients are available. The 65 patients considered evaluable for response had completed at least their 2nd cycle of treatment and had a tumor assessment, which could be compared to their baseline. This study is ongoing, and final results may change from the initial analysis.
"My colleagues and I are very excited by the results of this study so far, " said Linda T. Vahdat, MD, Associate Professor of Clinical Medicine and Medical Director, Breast Cancer Program at Cornell University New York Presbyterian Hospital. "We look forward to additional studies with this novel compound."
Pre-clinical studies demonstrate that E7389 suppresses the growth of cellular microtubules, which are essential for cell division. By doing so, E7389 appears to stop the production of new cancer cells and ultimately results in the programmed death of the existing cancer cells, a process known as apoptosis.