Phase II BiovaxID® lymphoma vaccine clinical trial results, presented by the NCI, demonstrated that vaccination following rituximab combination chemotherapy induced nearly universal T-cell immune responses, the elevation of which strongly correlated with overall survival and time-to-next treatment benefits in patients with mantle cell lymphoma (MCL), a highly aggressive form of B-cell non-Hodgkin’s lymphoma.
Wyndham H. Wilson, M.D., Ph.D., Chief of the Lymphoma Therapeutics Section at NCI and the principal investigator of the MCL study, stated in an article published in Genetic Engineering & Biotechnology News (GEN), “We found that among MCL patients treated with a hybridoma-based idiotype vaccine, patients who had T-cells that produced GM-CSF when exposed to tumor antigen had a significantly longer survival and delayed time to next treatment compared to patients who did not have GM-CSF producing T-cells. Interestingly, studies have shown that GM-CSF producing T-cells are important for promoting autoimmunity, which is what we hope an antitumor vaccine will do. In the latter case, the autoimmunity is against a tumor antigen and not a normal cell.”
Overall Survival Benefit in MCL: Patients with a high degree of this T-cell response to vaccination experienced an estimated survival of approximately 75% at 10-years, compared to a survival of approximately 25% in the group of patients with a low degree of T-cell GM-CSF responses. Overall, patients with the T-cell response experienced an approximately three-fold improvement in their probability of survival compared with those did not achieve this response to vaccine.
Time-to-Next Treatment Benefit in MCL: In addition to the overall survival benefit observed, there was also a highly statistically significant association between the BiovaxID-induced T-cell response and time-to-next-treatment benefit with a nearly a 10-fold improvement for those patients that developed this specific BiovaxID-induced T-cell response versus those who did not (51.9 months versus 5.5 months from the time of first progression)
According to Carlos F. Santos, Ph.D., Biovest’s Senior Vice President, Product Development & Regulatory Affairs, “We believe that these study results from the Phase II bridging study conclusively demonstrate that BiovaxID vaccine consolidation engenders strong anti-tumor T-cell immune responses following rituximab-combination chemotherapy which correlate with long-term clinical benefits. With our vaccine’s T-cell activating properties, long persistence of effect, high degree of safety and a mechanism of action that complements rituximab, BiovaxID represents an urgently needed non-immunosuppressive consolidation therapeutic option for lymphoma patients. These study results suggest that with minimal toxicity, BiovaxID induces tumor-specific T-cell responses which could dramatically slow tumor growth and improve survival in lymphoma patients.”