OBI-866

OBI-866 is an investigational **therapeutic cancer vaccine** developed by OBI Pharma that targets **stage-specific embryonic antigen-4** on tumor cells. It is a **glycoconjugate vaccine** composed of the tumor-associated carbohydrate antigen **SSEA-4** chemically linked to **keyhole limpet hemocyanin**, and it has been designed for use with the adjuvant **OBI-821** to stimulate **SSEA-4-specific IgM and IgG antibody responses**. The intended mechanism is active immunization against SSEA-4-expressing cancers, thereby enabling the patient's immune system to recognize and attack malignant cells. OBI-866 received Taiwan regulatory clearance for Phase 1 testing, but the program was subsequently terminated by 2025.

Other names

SSEA-4-KLH conjugate vaccineSSEA4-KLH conjugate vaccineSSEA 4-KLH conjugate vaccine