Summary: Adding monoclonal antibodies to chemotherapy appears to help patients with follicular lymphoma live longer. That's the conclusion of a study published recently in the Journal of Clinical Oncology. The researchers looked at the results of clinical trials performed in the last 30 years and found that patients given these new treatments are living longer and experiencing longer cancer-free periods.

Why it's important: Lymphomas are diagnosed in about 64,000 people in the US each year. Of these, about 14,000 people will have follicular lymphoma. Although this type of lymphoma is considered to be incurable, it tends to be slow-growing and people can live many years with it. Between 60% and 70% of patients will survive at least 5 years after their diagnosis. Follicular lymphoma can be successfully treated with chemotherapy, but it invariably comes back. Over the years, clinical trials of different chemotherapy combinations have been conducted. No matter what drugs and combinations were used, patients inevitably relapsed at about the same time, usually within 7-10 years.

What's already known: In the past few years, a new type of drug called a monoclonal antibody has proved successful in treating lymphomas. People naturally produce antibodies directed against viruses or bacteria to fight infections, but monoclonal antibodies are made in laboratories. They can be designed to kill lymphoma cells or other specific types of cancer cells. Some monoclonal antibodies kill cells by themselves, while others have a radioactive atom attached to help in the killing process. Studies with a common type of lymphoma, called large-cell lymphoma, found that adding monoclonal antibodies to chemotherapy cured more people than chemotherapy alone. But it wasn't known how successful this approach would be with follicular lymphomas.

How this study was done: This study reviewed several clinical trials of follicular lymphoma treatment that began in the early 1970s. Some of the studies used chemotherapy alone, while more recent ones added one of two monoclonal antibodies to the mix -- either rituximab (Rituxan, manufactured by Genentech and Biogen-Idec) or I-tositumomab (Bexxar, a radioactive antibody made by GlaxoSmithKline and Corixa). Several of the study authors have consulted for these companies, or received honoraria or research funds from them.

What was found: Patients who got the monoclonal antibody added to their chemotherapy tended to live longer. The 4-year survival rate for patients receiving chemotherapy alone ranged from 69% to 79%, compared to 91% for those who got chemotherapy plus a monoclonal antibody. The authors pointed out that it wasn't clear if Bexxar worked better than Rituxan. They are proposing a clinical trial to study this.

The bottom line: Adding a monoclonal antibody to chemotherapy increased the lifespan of patients with follicular lymphoma. Some experts caution that this kind of a study is not positive proof because patients treated more recently may have done better thanks to modern advances in supportive treatments. Nevertheless, the evidence from these studies, and others, has led to the acceptance of monoclonal antibodies and chemotherapy as the standard treatment for patients with follicular lymphoma.

Citation: "New Treatment Options Have Changed the Survival of Patients With Follicular Lymphoma." Published in the Nov. 20, 2005, Journal of Clinical Oncology (Vol. 23, No. 33: 8447-8552). First author: Richard I. Fisher, MD, James P. Wilmot Cancer Center.