GI-6207 / CEA


GI-6207 targets carcinoembryonic antigen (CEA), a protein that is over-expressed in a large number of epithelial cancers

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 cancers.  We estimate that CEA is over-expressed in approximately 500,000 new cancer cases in the United States each year.  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.

In July 2015, Celgene exercised its option to obtain an exclusive license to the GI-6200 program, including GI-6207.

Clinical Program

Phase 2 – Medullary Thyroid Cancer (MTC)

The American Cancer Society estimates that there were approximately 60,220 new thyroid cancer cases in the United States in 2013. We believe MTC accounts for 8% of thyroid cancer cases annually in the United States. Studies show that CEA is over expressed in over 60% of MTC. Surgery is currently the only curative treatment for MTC. Patients who develop metastatic MTC have a poor prognosis, with approximately 25% and 10% alive at five and ten years, respectively. Furthermore, metastatic MTC is largely unresponsive to conventional chemotherapy and radiotherapy. The only approved drugs for metastatic disease have demonstrated limited clinical benefit and substantial toxicity.

GI-6207-02 is a randomized Phase 2 study being performed at the National Cancer Institute (NCI) that is planned to enroll a total of 34 subjects in a cross-over trial design. Subjects will be treated with either GI-6207 for one year or be observed for six months and then treated with GI-6207 for one year. The primary endpoint for the trial will be the effect of GI-6207 on changes in calcitonin levels. Calcitonin is a tumor marker that can be measured in a patient’s circulating blood that correlates with tumor burden in MTC. Elevated calcitonin values after surgery indicate persistent or recurrent disease.)

Phase 1 – Safety Study

The NCI has completed a dose escalation Phase 1 clinical trial of GI-6207 in 25 subjects with Stage IV cancers expressing CEA.