Accentia Biopharmaceuticals, Inc.'s subsidiary Biovest International Inc., has announced that the US National Cancer Institute (NCI) presented the long-term (median 10-year follow-up) outcomes from a phase II BiovaxID lymphoma vaccine clinical trial at the 2012 American Society of Clinical Oncology Annual Meeting (ASCO 2012).

The 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, MD, PhD, 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.”

Additionally, Sattva S Neelapu, MD, associate professor at the Department of Lymphoma/Myeloma, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Centre (Houston, TX), a co-investigator of this phase II study and an investigator on the phase III (BV301) BiovaxID clinical trial in follicular lymphoma, commented that, “These results complement the body of data supporting the safety and efficacy of BiovaxID.”

The study (n=24), with 122 months of median potential follow-up (range: 111-132 months), demonstrates a median overall survival of 104 months, exceeding reported historic overall survival rates for ‘low-risk’ MIPI patients and substantially exceeding reported historic overall survival rates for ‘high-risk’ and ‘intermediate-risk’ MIPI patients. Furthermore, the study demonstrates a highly statistically-significant association between overall survival and specific vaccine-induced anti-tumour GM-CSF cytokine (T-cell) responses.

Overall Survival Benefit in MCL: Patients with a high degree of this T-cell response to vaccination experienced an estimated survival of approximately 75 per cent at 10-years, compared to a survival of approximately 25 per cent 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, PhD, 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-tumour 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 tumour growth and improve survival in lymphoma patients.”

The conclusions for BiovaxID MCL Study:

At 11-years follow-up, post-vaccination GM-CSF producing anti-tumour T-cells were significantly associated with overall survival and time-to-next-treatment benefits.

Results suggest that post-vaccination GM-CSF producing T-cells induce clinically significant anti-tumor effects which could slow tumor growth and improve survival.

Pre-treatment GM-CSF producing anti-tumor T-cells correlated with post-treatment enhancement of immune response, suggesting a priming effect.

This is the first evidence that idiotypic vaccination may improve survival of MCL, an aggressive B-cell subtype of non-Hodgkin’s lymphoma for which there is no current consensus standard-of-care.

Biovest International, Inc. is an emerging leader in the field of active personalized immunotherapies. In collaboration with the National Cancer Institute, Biovest has developed a patient-specific, cancer vaccine, BiovaxID, with three clinical trials completed, including a phase III study, demonstrating evidence of safety and efficacy for the treatment of indolent follicular non-Hodgkin’s lymphoma.