GI-6207 is a Tarmogen that expresses a modified version of the human carcinoembryonic antigen (CEA) protein as the target cancer antigen.
CEA is over-expressed in a number of human epithelial cancers, including non-small cell lung cancer (NSCLC), colorectal, pancreas, breast, gastric and medullary thyroid cancer (MTC). We estimate CEA is over-expressed in approximately 500,000 new cancer cases in the United States each year. The American Cancer Society estimates that there are over 56,000 new thyroid cancer cases annually in the United States. We believe that CEA represents an attractive target antigen since it is over-expressed in many cancers. Because CEA is minimally or not expressed in normal cells, we believe GI-6207 can be used for targeted reduction of cancer cells with little or no effect on normal tissues.
A Phase 1 dose escalation clinical trial of GI-6207 has been completed at the National Cancer Institute (NCI).
- Twenty-five patients with Stage IV cancers expressing CEA were enrolled into three dose groups.
- Five subjects have had stable or decreased CEA levels and stable disease on treatment. Only one subject experienced a grade 3 toxicity, defined as an event severe enough to interfere with daily living activities. This subject had pleural and pericardial metastases, or cancer in the spaces surrounding the heart and lungs, at the beginning of the study. The trial investigator and sponsor believed the event was likely caused by a therapeutic immune response directed at the metastatic lesions. The grade 3 toxicity resolved with cessation of GI-6207 therapy and treatment with corticosteroids. The patient resumed treatment with chemotherapy.
- A Phase 2 clinical trial is being designed in collaboration with the NCI to treat patients with MTC tumors expressing CEA.