Treos Bio Limited, an immuno-oncology company developing next-generation, off-the-shelf precision cancer vaccines coupled with companion diagnostics, today said it had successfully activated its clinical trial site at the Mayo Clinic in Rochester, Minnesota for its Phase 1 trial of PolyPEPI™ 1018, its investigational precision cancer vaccine for patients with metastatic colorectal cancer (mCRC).

The Mayo Clinic will serve as the only U.S. site for the Phase 1 trial, which will investigate the safety, tolerability, and immunogenicity of the PolyPEPI 1018 CRC Vaccine as an add-on treatment to the standard-of-care maintenance therapy in patients with metastatic colorectal cancer. Vaccine induced T cell immune responses and tumor-infiltrating lymphocytes will be determined by bioassays and the correlation with the predicted T cell immune responses will also be assessed.

“While progress has been made in treating colorectal cancer and improving outcomes, metastatic colorectal cancer is today the second leading cause of cancer death in the United States,” said Dr. Menghis Bairu, Executive Chairman of Treos. “There is an urgent need for new therapeutic options.”

A total of 10 adult patients between the ages of 18 and 75, who have experienced either a partial response or stable disease during first‑line treatment with a systemic chemotherapy regimen and one biological therapy regimen, will be enrolled in the study. Patients interested in participating in the study can find a fuller description of the enrollment criteria on the ClinicalTrials.gov website [ClinicalTrials.gov Identifier: NCT03391232].

“Treos has long worked to understand how to stimulate the human immune system to destroy tumor cells without attacking healthy cells,” said Franco Lori, M.D, Ph.D., Chief Medical Officer of Treos Bio. “As the pieces are now in place to begin enrolling patients in this first-in-man clinical trial of our off-the-shelf, precision cancer vaccine, it moves us one step closer to addressing an unmet need of patients and combatting this deadly disease.”

About PolyPEPI™ 1018 CRC Vaccine
The vaccine contains six synthetic peptides that are precisely selected to induce T cell responses against 12 epitopes from seven cancer testis antigens (CTAs) most frequently expressed in colorectal cancers. These peptides are optimized with the PEPI biomarker to induce robust and lasting CRC specific T cell responses.

About Colorectal Cancer
Colorectal cancer is the third most common cancer worldwide, accounting for 9.7 percent of all cancers apart from non-melanoma skin cancers with nearly 700,000 deaths in 2012 from colorectal cancer worldwide, according to GLOBOCAN. While improvements in cancer care have boosted survival rates for all stages of colorectal cancer in the past two decades, the prognosis for patients with metastatic colorectal cancer remains grim. The five-year relative survival rate for patients with metastatic colon cancer is just 11 percent. For patients with metastatic rectal cancer, the five-year relative survival rate is just 12 percent, according to the American Cancer Society.