May 15, 2002 -- A new generation of anticancer treatments can prolong the lives of patients with hard-to-treat cases of non-Hodgkin's lymphoma who have exhausted all other options. New research shows the first of a class of drugs that uses radioimmunotherapy to hone in on and kill cancers is also effective at zapping non-Hodgkin's lymphoma B cells.
The study appears in today's issue of the Journal of Clinical Oncology.
Radioimmunotherapy uses laboratory-created antibodies, similar to those produced by the body in response to cancers, to target radiation treatment directly at the site of the cancer. The mixture of antibodies and radiation is delivered intravenously and travels through the blood to the cancer cells.
Researchers at the Mayo Clinic studied the ability of the first radioimmunotherapy drug designed specifically to treat low-grade B cell non-Hodgkin's lymphoma, Zevalin. About 56,000 Americans are diagnosed each year with this common, but usually fatal, type of cancer of the lymph glands.
The researchers found that 80% of patients who received Zevalin had a positive response to the drug and their tumor shrank, compared with only 56% who had a similar response to another drug used to treat the cancer, Rituxan. Also, 30% of the patients using Zevalin had a complete remission of their disease with no trace of the cancer present, compared with only 16% of those taking Rituxan.
Since the drug targets only the cancer cells it's designed to destroy, researchers say the treatment is more effective than traditional approaches and has fewer side effects.
"Unlike chemotherapy which goes through the whole body, Zevalin carries the radiation payload directly to the tumor," says study author Thomas Witzig, MD, a hematologist at the Mayo Clinic, in a news release. "The drug radiates only about a 5 mm area around the tumor."
"One treatment is required on an outpatient basis, compared to a series of treatments with chemotherapy that can last four to six months and sometimes include hospitalization because of serious side effects," says Witzig. "There's no hair loss or prolonged fatigue, nausea, or vomiting. The most significant side effect is a temporary decrease in the blood count."
Based on the results of this phase III clinical trial and others, the FDA recently approved Zevalin for treatment of patients with relapsed B cell non-Hodgkin's lymphoma.