Mantle Cell Lymphoma Patients Benefit from Vaccine and Immune-Depleting Therapy

A phase II clinical trial has found that some mantle cell lymphoma patients may have benefited from an experimental cancer vaccine and the novel dose-adjusted EPOCH chemotherapy regimen with the drug rituxan. Although 80 percent of the patients eventually relapsed after the treatments, they lived longer on average than others with mantle cell lymphoma. After nearly 4 years, 89 percent of the patients were alive; typically, half the patients with this disease die within 3 years.

It is not clear whether the vaccine or some combination of the treatments were responsible for the prolonged survival. But the study, which included 26 patients, demonstrates that a vaccine can stimulate the body's T cells to attack the mutant B cells responsible for the lymphoma. This was true despite the fact that rituxan had eradicated the healthy B cells in these patients along with the mutant B cells.

"This study shows that healthy B cells were not necessary for generating a T-cell response, and the role of these cells in generating a T-cell response has not been known in humans," says Dr. Wyndham Wilson of NCI's CCR. He co-led the study along with Dr. Larry Kwak of the University of Texas M. D. Anderson Cancer Center.

The researchers made "personalized" vaccines for each patient based on a unique protein found on the surfaces of a patient's mutant B cells. The results, published in the August 21 Nature Medicine, suggest that additional doses of the vaccine should be administered for longer periods of time to achieve an optimal immune response.

"We're now trying to make the vaccine formulation more potent, and we're also investigating a universal vaccine that might be effective in every lymphoma patient," says Dr. Sattva Neelapu of M.D. Anderson and the first author of the study.