Generex Biotechnology Corporation (Nasdaq:GNBT) announced on October 9 that Dr. Minzhen Xu, Vice President of Biology at Antigen Express, Inc., the company's immunotherapy subsidiary, will present "Inhibition of MHC class II-associated Invariant Chain Generates Potent Tumor Cell Vaccine" at the 12th World Congress on Advances in Oncology.

The talk by Dr. Xu will present pre-clinical studies that Antigen Express has performed in preparation for clinical trials in China. Robust anti-tumor immunity has been demonstrated in a variety of mouse tumor models as well as safety using the RNAi approach developed at Antigen Express. The trials in China will be performed in collaboration with Dr. Daopei Lu and the Beijing Daopei Hospital in Beijing, China. Dr. Lu is a world-renowned hematologist-oncologist who has conducted many clinical trials and has authored over 200 articles in peer-review journals.

The strategy being developed by Antigen Express is to force tumor cells to express tumor associated antigens in a way that makes them more visible to the immune system. This is done by suppressing expression of the MHC class II-associated invariant chain in tumor cells using RNAi. MHC class II molecules are naturally expressed in many cells of the body including some types of cancer cells. The invariant chain prevents class II molecules from associating with antigenic peptides in the cytoplasm of cells (where tumor associated antigens are found) and presenting them for recognition by T helper cells. Antigen-specific stimulation of T helper cells is pivotal in allowing the immune system to recognize novel pathogenic agents. While a number of groups have demonstrated the efficacy of this strategy in pre-clinical models, Antigen Express has developed proprietary methods using RNAi that make this approach feasible in the clinic.

Antigen Express is focused on developing active immunotherapy products for serious diseases and unmet medical needs. Currently the company has an immunotherapeutic peptide in Phase II clinical trials for breast cancer and in Phase I trials for the potentially pandemic H5N1 avian influenza.