by Kylie Chen | October 5, 2020
Imagine being part of a civil war you didn’t even know you were fighting. The war is corrupting your side, and by the time anyone notices this damage, it could be too late. Your opponents may have already infiltrated you without you realizing, waiting for the right time to strike and destroy your side.
This war is between your body and cancer. Cancer cells mutate from your cells, sometimes managing to spread through your body undetected until your death is imminent. Over time, scientists have come up with multiple ways of treating cancer, including surgery, radiation therapy, chemotherapy, immunotherapy, and CAR T-cell therapy. However, such solutions can be physically, financially, and emotionally taxing, even potentially posing other health risks.
But what if your body could fight the cancer with nothing more than a mass-producible, generalizable, immune-boosting solution?
Fiction became reality on September 10, 2020: the Wistar Institute published a press release about its nanoparticle antitumor vaccine, which successfully stimulated CD8 T-cell immunity while controlling the growth of melanoma, a type of skin cancer.
So, what is a nanoparticle antitumor vaccine, and how does it work?
To understand this, we first need to investigate cancer and the immune system’s response to cancer. Cancer occurs due to gene mutations in particular cells, causing those cells to grow uncontrollably. Normally, they clump together to form a tumor. Sometimes, the cancer cells trigger the immune system to send in T-cells, designed to kill malignant bodies. The tumor cells may also manage to completely hide themselves from the immune system, continuing the spread of mutant cells throughout the body.
If the tumor is localized, then surgery or radiation therapy combined with chemotherapy may eradicate the cancer cells. However, once the cancer spreads to other parts of the body and becomes stage IV cancer, surgery and radiation therapy will not help. While immunotherapy and CAR T-cell therapy may treat advanced cancer stages, like IIIb and IV, both are expensive: immunotherapy costs over $100,000 per round, and CAR T-cell therapy is even pricier, nearing half a million dollars. Although these two treatments work for some, they are not guaranteed to eradicate the cancer or prolong life.
The nanoparticle vaccine, on the other hand, boosts the immune system’s response against cancer by triggering CD8 T-cells. When injected into a patient, the vaccine releases tiny particles bound with model tumor antigens. These antigens prompt the immune system into action, effectively stripping away the cancer cells’ disguise and making the immune system aware of the tumor’s presence. The immune system then sends T-cells to kill the malignant cells.
If approved as a cancer treatment, a nanoparticle vaccine would be used in the way that immunotherapy and CAR T-cell therapy are applied to stage IV cancer. What differentiates them? For one, it should be much cheaper than CAR T-cell therapy, which is personalized per patient. It takes a lot of effort to reprogram a person’s T-cells and inject them back into the person to fight off the cancer. In addition, a nanoparticle vaccine, like immunotherapy, may be used on anyone who has previously had the same type of tumor.
Although this vaccine has only been studied in preclinical models, if successful on a larger scale, it could change how we see and treat cancer. Nanoparticle vaccines could change the course of medicine and save the lives of the tens of millions affected by cancer around the world.