The median follow-up was 3.8 years. Historically, patients with this type of lymphoma only have had a 50% chance of surviving 3 years and 20% chance of surviving 5 years. BiovaxID, an investigational personalized anti-cancer vaccine, stimulates the immune system to seek out and destroy tumor cells. The data were published in a recent edition of Nature Medicine (Nat Med.2005; 11(9):986-91).
In this single-arm, open-label Phase 2 clinical study, patients with untreated mantle cell non-Hodgkin's lymphoma (NHL) were administered six cycles of dose-adjusted EPOCH-R, a chemotherapy regimen that includes Rituxan® (rituximab). Of the 26 patients in the study, 23 received vaccinations with BiovaxID commencing at least three months after completing their last chemotherapy and Rituxan treatments. Upon the 46-month (3.8-year) follow-up, the overall survival rate was 89%. This study showed that, despite an almost complete depletion of normal B-cell lymphocytes due to EPOCH-R therapy, BiovaxID did induce anti-tumor T-cell lymphocyte responses in most patients. Depletion of normal B-cell lymphocytes is a consequence of the combination of chemotherapy and Rituxan, but not of BiovaxID therapy. Thus, "it is justifiable to administer vaccines in the setting of B-cell depletion, but vaccine boosts after B-cell recovery may be necessary for optimal humoral responses," concluded the investigators.
Lymphocytes are a type of white blood cell. There are two types of lymphocytes: B-cell lymphocytes, which produce antibodies ("humoral" immunity) in response to immune stimulation; and T-cell lymphocytes, which mediate cell responses to immune stimulation ("cellular" immunity). B-cell lymphocytes can undergo malignant transformation to become non-Hogkins lymphoma, multiple myeloma or chronic lymphocytic leukemia.
"This is the first human cancer vaccine study to see T-cell responses in the absence of B-cells," said the study's first author, Sattva Neelapu, M.D., Assistant Professor in the Department of Lymphoma at the University of Texas M. D. Anderson Cancer Center. "This paves the way to use vaccines in a number of hematological cancers that are treated by eliminating diseased B-cells."
Biovest is now enrolling patients in a pivotal Phase 3 trial to test BiovaxID against follicular non-Hodgkin's lymphoma (NHL). Follicular NHL is an indolent (slow-growing) form of lymphoma not considered curable with existing therapies. The impressive findings from the Phase 2 clinical trial using BiovaxID in mantle cell lymphoma suggest the vaccine could potentially be used to treat other types of NHL, in addition to follicular NHL.