Phase II trial results show investigational drug regorafenib slowed the progression of tumors and lengthened the lives of patients with metastatic colorectal cancer, said Mayo Clinic oncologist Axel Grothey, the U.S. trial’s principal investigator.

The trial was randomized, placebo-controlled and conducted simultaneously in the U.S., Europe, Japan, China and Australia. Researchers studied the survival outcomes in 760 patients whose cancer had progressed despite standard chemotherapy regimens.

U.S. results showed patients with metastatic colon cancer who were treated with the drug showed a 29% increase in overall survival when compared to those treated with placebo. The median length of survival 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%.

“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,” said 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.”

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 activated in tumors.