Biovest International's phase 2 trial conducted by the National Cancer Institute (NCI) that shows Biovest's BiovaxID yielded an 89% survival rate in mantle cell lymphoma patients. 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 personalised anti-cancer vaccine, stimulates the immune system to seek out and destroy tumour cells.
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-tumour 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, claims the company release.
"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 humoural responses," concluded the investigators.
"This is the first human cancer vaccine study to see T-cell responses in the absence of B-cells. This paves the way to use vaccines in a number of haematological cancers that are treated by eliminating diseased B-cells," said the study's first author, Sattva Neelapu, assistant professor in the Department of Lymphoma at the University of Texas.
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.
Rituxan is a passive immunotherapeutic consisting of a monoclonal antibody administered intravenously. The monoclonal antibody is directed to an antigen (CD20) present on most B-lymphocytes.
BiovaxID is an active immunotherapeutic that stimulates the production of anti-tumour antibodies and induces a cell-mediated immune response to cancerous B-lymphocytes but not to normal B-lymphocytes.
Biovest International Inc develops advanced individualised immunotherapies for life-threatening cancers of the blood system. Biovest is a majority owned subsidiary of Accentia Biopharmaceuticals Inc.