An immune system-boosting cancer treatment that recently demonstrated astounding results in mice is now advancing to human testing.
Published less than two months ago in Science Translational Medicine, a study by Stanford University researchers showed that injection of two immune-stimulating agents directly into a tumor caused T-cells to recognize and destroy cancerous cells in both the local tumor as well as a distantly located secondary mass.
Because the combination treatment provokes an immune response and can be easily administered by an injection, the scientists have referred to it as a cancer “vaccine”, although technically speaking it is not a true vaccine.
Normally, T-cells are infective against tumors because the malignant cells within are either too similar to healthy cells to be recognized or the cancerous cells actually excrete chemicals that allow them to go undetected.
Existing antibody-based cancer treatments get around this by targeting cancerous cells through highly specific mutations, but consequently only work on certain cancers. The newly approved CAR T-cell therapies also work by boosting T-cell function, yet the treatment requires each individual patient’s immune cells to be genetically engineered.
Thus, the Stanford team’s finding that a simple injection of two agents caused mouse T-cells to mobilize themselves against genetically identical nearby cancer cells – plus far away ones that mimic metastasized cells – is quite remarkable. Moreover, the treatment was effective against multiple types of cancer. The best results, a whopping 97 percent cure rate, were seen against lymphoma.
Now, the researchers will evaluate the injection in humans with a subtype of lymphoma called low-grade B-cell Non-Hodgkin.
Dr Ronald Levy, leader of the planned phase 1 trial and senior author of the mouse study, told the SF Gate that he and his colleagues hope to enroll a total of 35 adult patients for two study groups by the end of this year.
Each participant will first receive low-dose radiation therapy to kill some cancer cells and weaken those that remain, followed by two rounds of treatment injection.
The aim of the trial will be to determine the optimal dose and examine the treatment’s side effects.
"The two drugs we are injecting are made by two different companies and have already been proven safe for people," Levy said. "It's the combination we are testing."
One of the treatment’s components is an antibody called anti-OX40 that activates both CD4 T-cells, helper cells that communicate with other immune cells, and CD8 killer cells, which, as the name suggests, release chemicals that destroy targeted cells.
The other ingredient is a short strand of synthetic DNA that tells immune cells to express a cell surface protein called TLR9 ligand – this, in turn, boosts antibody production and leads to the creation of specialized memory cells whose purpose is to quickly sound the alarm if the same threatening cell reappears in the future.