NEW YORK – ImmunityBio said on Tuesday that it has launched a clinical trial to evaluate its investigational Tri-Ad5 vaccine combination (Adenovirus 5 CEA/MUC1/brachyury) plus its interleukin-15 superagonist immune enhancer as an intervention to prevent cancer among people with Lynch syndrome.
In the Phase IIb trial, which is sponsored by the National Cancer Institute, 186 participants with Lynch syndrome — defined as having either a mutation in MLH1, MSH2/EPCAM, or MSH6 with a prior history of adenoma, advanced adenoma, or colon cancer, or having a PMS2 mutation with a prior history of colon cancer — will receive the three-vaccine combination plus the immune enhancer, dubbed N-803.
The three vaccines involved in Tri-Ad5 each target different proteins associated with cancer and precancer cells. The goal is to activate dendritic cells and train the immune system to recognize the proteins so it can attack precancerous cells before they develop into full-fledged cancer. The immune enhancer is supposed to increase the proliferation and activation of natural killer cells and T cells.
The primary endpoint of the Tri-Ad5 trial is the cumulative incidence rate of adenomas, advanced adenomas, and colon cancers that develop among the participants after 104 weeks. The rate will be compared to that of a group of participants who receive a placebo.
According to Culver City, California-based ImmunityBio, the trial will be the largest Lynch syndrome cancer prevention study in the US to date.
"Currently, there is no treatment that prevents the development of cancer in these patients," Patrick Soon-Shiong, ImmunityBio's executive chairman and global chief scientific and medical officer, said in a statement. "We hope to change that with this innovative study developed by the NCI."