OBI-866 is an active immunotherapeutic cancer vaccine targeting SSEA-4, a tumor associated carbohydrate antigen highly expressed in many cancers. OBI-866 is a conjugate of SSEA-4 and carrier protein Keyhole limpet hemocyanin (KLH). OBI-866 is designed to be used in combination with the adjuvant OBI-821, to elicit SSEA-4 specific IgM and IgG immune responses therapeutically.
The advantage of OBI-866 lies within the inherent property of a vaccine—activating patients’ own immune system to fight diseases, in this case fighting cancers. When patients’ immune system has the ability to exert cytotoxic killing effect on SSEA-4 expressing tumor cells , it provides long-term protection against the disease. Compared to conventional chemotherapy, immunotherapy reduces damaging normal cells and further lowers the degree of toxicity related side effects. As targeted tumor cells typically have higher SSEA-4 expression, the required level of SSEA4 antibody for effective anti-cancer therapy can be induced at low dose of OBI-866. OBI-866 thus can potentially be a safer and more effective treatment than standard chemotherapy and targeted therapy for cancer treatment.
OBI-866 in currently in pre-clinical stage.