Combining radiation and chemotherapy with Erbitux, a cancer-targeting agent that attacks specific receptors on the surface of tumor cells, is showing promising results in treating patients with advanced esophageal cancer.
In a Phase II clinical study conducted at the University of Maryland Marlene and Stewart Greenebaum Cancer Center and the Brown University Oncology Group, 75 percent of the patients treated with this therapy had no evidence of cancer after treatment. Seventy percent of the patients were still alive after one year.
The results of the study were presented earlier this month at the annual meeting of the American Society of Therapeutic Radiology and Oncology (ASTRO) in Philadelphia. The 18-month study, which began in April 2005, is one of the first to look at the use of radiation, chemotherapy and a ?biologic agent? such as Erbitux to treat esophageal cancer. Erbitux (cetuximab) is approved by the U.S. Food and Drug Administration for treating head and neck cancer and colon cancer.
The National Cancer Institute is considering initiating a national Phase III clinical trial to compare this therapy with standard chemotherapy and radiation, which are used, along with surgery, to treat esophageal cancer.
?We are excited about how well patients responded to this treatment. The response rate is significantly higher than what we typically see with esophageal cancer patients who are treated with chemotherapy and radiation alone,? says Mohan Suntharalingam, M.D., co-principal investigator and professor and vice chairman of the Department of Radiation Oncology at the University of Maryland School of Medicine. He notes that 40 percent of patients who receive standard chemotherapy and radiation are tumor-free after treatment.
Dr. Suntharalingam adds that researchers have only one-year survival data for the new treatment and want to see how well patients do over the next few years.
Esophageal cancer is often difficult to diagnose and treat, and about 20 percent to 25 percent of patients are still alive five years after treatment. The incidence of esophageal cancer, especially a form called esophageal adenocarcinoma in the lower part of the esophagus, is on the rise. The American Cancer Society estimates that more than 14,000 new cases of esophageal cancer will be diagnosed this year, with an equal number of people dying of the disease.
Sixty patients participated in the clinical trial, 32 of them at the University of Maryland Greenebaum Cancer Center and 28 at the Miriam Hospital, which is affiliated with the Brown University Oncology Group. Howard Safran, M.D., a medical oncologist from Brown, was also a co-principal investigator.
The patients were treated for six weeks with two chemotherapy drugs (paclitaxel and carboplatin), cetuximab (Erbitux) and radiation. Doctors then evaluated them to determine if they were candidates for surgery.
Erbitux is what is known as a monoclonal antibody, a genetically engineered version of a mouse antibody that targets a natural protein on the surface of cancer cells called epidermal growth factor receptor, or EGFR. Antibodies are produced by the body?s immune system to fight foreign substances. Erbitux was approved in 2004 for use in treating colon cancer and this year for head and neck cancer. Monoclonal antibodies are being used to treat a variety of cancers.
Dr. Suntha says that patients in the esophageal cancer study experienced few side effects. ?They were able to tolerate this therapy better than they have historically tolerated chemotherapy and radiation approaches,? he says.
The University of Maryland Marlene and Stewart Greenebaum Cancer Center is recognized for its multidisciplinary approach to cancer care, with teams of specialists who work together to evaluate and treat patients. It also has strong basic and clinical research programs.