The trial (NCT03391232), which is still recruiting, is testing the vaccine as an add-on to standard treatment for metastatic colorectal cancer and is expected to include 10 participants, between 18 and 75 years old. To be eligible, patients must have achieved a prior partial response or stable disease with first-line chemotherapy and biological therapy.
In addition to the vaccine’s safety and tolerability, investigators will also assess how the immune system behaves after treatment.
“While Treos has made great progress and we are proud to achieve this milestone of dosing the first patient in this first-in-man study of our precision cancer vaccine, we feel the urgency of patients with metastatic colorectal cancer in search of better therapeutic options,” Menghis Bairu, MD, executive chairman of London-based Treos, said in a press release.
PolyPEPI 1018 is a cancer vaccine that contains six synthetic proteins similar to those commonly found in colorectal cancer cells. This induces long-lasting immune responses against colorectal tumors, while sparing healthy cells. Because the immune system becomes primed for several cancer proteins, the vaccine is able to target multiple cancer cells.
Treos has also developed a companion diagnostic test that identifies patients who are likely to benefit from the vaccine. The test uses genetic data obtained from a saliva or blood sample to predict how each patient’s immune system will respond to the synthetic proteins in the vaccine.
“Treos has long worked to understand how to stimulate the human immune system to destroy tumor cells without attacking healthy cells,” said Franco Lori, MD, PhD, chief medical officer of Treos Bio. “As we treat the first patient in this study 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.”