Enrollment Completed for SIRFLOX Study of Sirtex's SIR-Spheres to Treat Colorectal Liver Metastases

April 13, 2013—Sirtex Medical Limited (Woburn, MA) announced yesterday the completion of patient enrollment in the SIRFLOX trial of selective internal radiation (SIR) therapy using the company's SIR-Spheres microspheres for patients with metastatic colorectal cancer. The randomized controlled SIRFLOX interventional oncology trial has enrolled more than 500 patients at more than 100 hospitals around the world over a 6-year period. Twenty-one sites have enrolled patients into the SIRFLOX study in the United States. Primary results from the study are expected to be available in late 2014.

According to Sirtex, the SIRFLOX study aims to evaluate whether a first-line treatment strategy of standard-of-care chemotherapy plus SIR-Spheres microspheres is more effective in delaying cancer progression than chemotherapy alone in patients with inoperable liver metastases from primary colorectal cancer. The company stated that it hopes the SIRFLOX study will demonstrate to the oncological medical community that combining chemotherapy and internal radiation therapy earlier in the treatment algorithm will benefit patients.

“Our clinical experience has shown SIR-Spheres microspheres to be an effective treatment option for patients with metastatic colorectal cancer,” commented SIRFLOX investigator Fred Moeslein, MD, in the company's press release. Dr. Moeslein is Interim Director of the Division of Vascular and Interventional Radiology at the University of Maryland School of Medicine in Baltimore, Maryland. “We are excited to be the top-enrolling United States site in this landmark study and look forward to seeing the results, which we believe will help further guide the oncology community in best practice treatment for liver tumors from metastatic colorectal disease.”

According to Sirtex's press release, SIR therapy (or radioembolization) is a proven technology for inoperable liver cancer that delivers doses of radiation directly to the site of tumors. In this minimally invasive treatment, millions of radioactive SIR-Spheres microspheres are infused via a catheter into the liver, where they selectively target liver tumors with a dose of internal radiation up to 40 times higher than conventional radiotherapy, while sparing healthy tissue. Clinical studies have confirmed that patients with metastatic colorectal cancer treated with SIR-Spheres microspheres have response rates higher than with other forms of treatment, resulting in increased life expectancy, greater periods without tumor activity, and improved quality of life. SIR therapy has been found to shrink liver tumors more than chemotherapy alone, the company stated.

SIR-Spheres microspheres are approved for use in the United States, the European Union, Australia, and Argentina. They are also available in other worldwide markets, advised Sirtex.