Cancer immunotherapy by intratumoral injection of α-gal glycolipids.

UNLABELLED AIM/ BACKGROUND: To determine the feasibility and safety of intratumoral α-gal glycolipids injection for conversion of human tumors into autologous Tumor Associated Antigens (TAA) vaccine. α-Gal glycolipids bind anti-Gal--the most abundant antibody in humans. Pre-clinical studies indicated that injected α-gal glycolipids insert into tumor cell membranes, bind anti-Gal and target tumor cells to Antigen Presenting Cells, thereby converting tumors into autologous TAA vaccines. We hypothesized that α-gal glycolipids might have similar utility in humans. PATIENTS AND METHODS Eleven patients with advanced solid tumors received one intratumoral injection of 0.1 mg, 1 mg, or 10 mg α-gal glycolipids. The primary endpoint was dose-limiting toxicity (DLT) within 4 weeks. Secondary endpoints included long-term toxicity, autoimmunity, radiological tumor response and survival. RESULTS There were no DLT and no clinical or laboratory evidence of autoimmunity, or any other toxicity. Few patients had an unexpectedly long survival. CONCLUSION Intratumoral injection of α-gal glycolipids is feasible and safe for inducing a protective anti-tumor immune response.