An investigational drug called regorafenib slowed the progression of tumors and lengthened the lives of patients with metastatic colorectal cancer, an international phase III clinical trial found. The findings were presented today at the Gastrointestinal Cancers Symposium of the American Society of Clinical Oncology in San Francisco by Mayo Clinic oncologist Axel Grothey, M.D., principal investigator of the trial in the United States.
"For years, patients with metastatic colorectal cancer have faced a devastating impasse when standard chemotherapies have failed to halt the growth of tumors and physicians have run out of effective drugs to offer them," says Dr. Grothey. "This is the first novel agent in eight years to show improvement in overall survival of colon cancer patients who have run out of treatment options."
Researchers tested regorafenib in a phase III, randomized, placebo-controlled trial, conducted simultaneously in the United States, Europe, Japan, Australia and China. They looked at survival outcomes in 760 patients whose cancer had progressed despite standard chemotherapy regimens. Regorafenib is a multi-kinase inhibitor, which has the effect of slowing cell proliferation and blood vessel growth and tempering a variety of biological pathways that are activated in tumors.
Researchers found that patients with metastatic colon cancer who were treated with the drug showed a 29 percent increase in overall survival when compared to those treated with placebo. The median length of survival for patients treated with the drug increased from 5 months to 6.5 months, a statistically significant jump. Overall, regorafenib reduced patients' risk of dying from cancer during the trial by 23 percent.
The trial, whose largest group of study participants in the United States was at Mayo Clinic, finished more than a year ahead of schedule.
"Patients with metastatic colorectal cancer who have failed all approved standard therapies have a poor prognosis," says Dr. Grothey. "This is the first and only agent in this setting that has demonstrated statistically significant overall survival benefit."