The seven mice in the therapeutic pilot study were given tamoxifen at week 9 and subsequently monitored via colonoscopy weekly. Once the presence of adenoma was identified, mice received six doses of TetMYB and four doses of anti-PD1 antibody.
In both the prophylactic and therapeutic study, the mice survival rates were higher than expected. In the prophylactic study, the treatment groups’ median survival time was 356 days, nearly double the control group (183 days). More impressively, all mice in the therapeutic group were alive at 235 days.
“The mice were only expected to live for a couple of days or weeks. But, about 50% of them, they lived for more than 2 years,” said Dr. Pham. “Additionally, when the cured mice from the original study were later rechallenged with the same treatment, it was immediately rejected, thus proving there is an immune memory induced by the vaccine.”
With the positive results of the mouse trial, Dr. Pham spoke to the ongoing human clinical trial and the future of this vaccine.