BACKGROUND:
* CEA is overexpressed in multiple malignancies, including medullary thyroid cancer where CEA is universally expressed on tumor cells.
* There is no standard treatment for patients with asymptomatic or minimally symptomatic, metastatic medullary thyroid cancer. The only effective FDA-approved therapy (vandetanib) comes with significant toxicity, so it is not used until patients have symptomatic or rapidly progressing disease.
* Preclinical studies have shown that GI-6207 can induce a strong immune response to CEA as well as therapeutic anti-tumor responses.
* A previous Phase I GI-6207 study has demonstrated safety and enhanced immune response in some patients.
* Preliminary data suggests that tumor growth rates can be calculated in medullary thyroid cancer patients within 3 months
* Retrospective data from prostate cancer studies suggest that vaccines can alter tumor growth rates within 3-4 months
OBJECTIVES:
Primary:
-To determine the effect of GI-6207 on calcitonin growth rate kinetics after 6 months of therapy in patients with medullary thyroid cancer
ELIGIBILITY:
* Patients will have evidence of metastatic medullary thyroid cancer including disease that is evaluable on bone or CT scan.
* Patients with minimal or no disease related-symptoms (minimal symptoms will include those that do not affect activities of daily living or pain that does not require regularly schedule narcotics.)
* ECOG 0-1
* No previous chemotherapy
* No previous vandetanib
* Should have no autoimmune diseases; no evidence of being immunocompromised; no serious inter-current medical illness; no cardiac disease; no prior splenectomy. (History of previous thyroid autoimmune disease will be allowed as these patients will have had total thyroidectomy.)
* No brain metastasis, history of seizures, encephalitis, or multiple sclerosis
* No pericardial-based masses greater than 1 cm or thoracic lesions larger than 2 cm
Design:
* Randomized, phase 2 study to determine the effect of GI-6207 on calcitonin growth rate after 6 months of GI-6207
* Patients will be randomized to either initial GI-6207 therapy or 6 months of surveillance followed by GI-6207 therapy.
* GI-6207 will be administered subcutaneously at 4 sites at dose of 10 yeast units per site, biweekly for 7 visits (day 1, 15, 29, 43, 57, 71, 85), then monthly up to 1 year of treatment. (For patients randomized to surveillance and then GI-6207, they will get a full year of GI-6207 after a 6 month surveillance period.)
* Once patients have completed one year of therapy with GI-6207, patients without radiographic progression will have the option to receive vaccine every 3 months for an additional 12 months. Patients who remain on vaccine will continue to be scanned every 3 months.
* Immune monitoring via apheresis will be done prior to enrollment and at 6 months for all appropriate and consenting patients. Patients who are evaluable for immunologic response by the ELISPOT Assay (HLA 02, 03 and 24) will have apheresis at start of GI-6207 therapy and then every 3 months while on GI-6207 treatment when feasible.