Related Experiment Video
Updated: Jan 7, 2026
In Vivo Inhibition of MicroRNA to Decrease Tumor Growth in Mice
Published on: August 23, 2019
A phase 2 study of GI-6207 in patients with recurrent medullary thyroid cancer
Jaydira Del Rivero1, Renee N Donahue2, Jennifer L Marte2
1Developmental Therapeutics Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, United States.
Background:
Medullary thyroid cancer (MTC) accounts for approximately 4% of thyroid carcinomas. Patients with unresectable, metastatic disease are candidates for approved agent-targeted therapies such as vandetanib, cabozantinib, or selpercatinib, but toxicity is often an issue. Preclinical data supported the potential use of immunotherapy targeting carcinoembryonic antigen (CEA) in this indolent disease.
Methods:
Patients with advanced/recurrent MTC were randomly assigned in a 1:1 ratio to receive a Saccharomyces cerevisiae (yeast)-based immunotherapy (GI-6207) targeting CEA starting at the time of enrollment or 6 months after surveillance. The primary endpoint was to compare the calcitonin growth rate in the GI-6207 arm at 6 months with patients in the surveillance arm at 6 months.
Results:
Between March 2013 and May 2018, 34 patients were randomly assigned to receive the yeast-CEA vaccine (GI-6207) starting at the time of enrollment or 6 months after surveillance. The mean age was 51 years, and 82% of patients were diagnosed with sporadic MTC. There was no significant change in the calcitonin growth rates at 6 months when the immunotherapy group was compared with the surveillance group (-2.490042 vs -2.526385; P = .3760). Treatment with GI-6207 was associated with increased peripheral CEA-specific CD4 and/or CD8 T cells, with 15/26 (58%) patients displaying increases after 3 months of treatment. One patient had a significant inflammatory event 17 months after the last vaccine at a known lymph node, perhaps related to a delayed immune response. There were no grade 3 or 4 adverse events. Grade 1 injection site reactions were most common.
Conclusion:
The immunotherapy was well tolerated but did not have an impact on tumor growth rate at 6 months as measured by calcitonin kinetics.
Clinical Trial Identification:
NCT01856920.
Insights
A novel yeast-based immunotherapy targeting carcinoembryonic antigen (CEA) showed good tolerability in patients with medullary thyroid cancer (MTC). However, this immunotherapy did not significantly impact tumor growth rates at six months.
Area of Science:
- Oncology
- Immunotherapy
- Thyroid Cancer Research
Background:
- Medullary thyroid cancer (MTC) represents about 4% of thyroid carcinomas.
- Targeted therapies like vandetanib, cabozantinib, and selpercatinib are available for advanced MTC but can cause toxicity.
- Preclinical studies suggested immunotherapy targeting carcinoembryonic antigen (CEA) as a potential treatment for MTC.
Purpose of the Study:
- To evaluate the efficacy and safety of a Saccharomyces cerevisiae (yeast)-based immunotherapy targeting CEA in patients with advanced or recurrent MTC.
- To compare the calcitonin growth rate at six months between patients receiving immunotherapy and those under surveillance.
Main Methods:
- A randomized controlled trial involving 34 patients with advanced/recurrent MTC.
- Patients were assigned 1:1 to receive yeast-CEA immunotherapy (GI-6207) at enrollment or after six months of surveillance.
- The primary endpoint was the comparison of calcitonin growth rates at six months between the two groups.
Main Results:
- No significant difference in calcitonin growth rates was observed between the immunotherapy and surveillance groups at six months (p=0.3760).
- The immunotherapy increased peripheral CEA-specific CD4 and/or CD8 T cells in 58% of patients after three months.
- The treatment was well-tolerated, with most adverse events being Grade 1 injection site reactions; no Grade 3 or 4 events occurred.
Conclusions:
- Yeast-based CEA immunotherapy (GI-6207) was well-tolerated in patients with advanced MTC.
- The immunotherapy did not demonstrate a significant impact on tumor growth rate, as measured by calcitonin kinetics at six months.
- Further research may be needed to explore the role of immunotherapy in MTC management.
Related Concept Videos
01:11Clinical Trials: Overview
01:16Clinical Trials
There are four phases in a clinical trial. A phase one...