Can This Discovery To Make Precision Immunotherapy Treatments Help You?
A recent study published by researchers from Cancer Research UK has shown a new method to provide more precise cancer immunotherapy. This type of therapy enhances the patients immune system’s efforts to find and kill the cancer cells. The discovery is a new way to help the immune system identify the cancer cells based on the cell complexity and the antigens it is vulnerable to and then destroy them.
When cancer cells spread, their mutations allow them to avoid the normal immune response and evolve to resist drugs. This makes them virulent and challenging to treat. If a way could be found to mark the cancer cells based on their antigens, which are proteins on the cancer damaged cells, then scientists would be better equipped to find new methods of improving the immune system response. Moving forward, as they gain a deeper understanding of antigens, researchers may be able to create special cells in the labs that can target these specific proteins. Cancer Research UK notes that these cells could form a “fearsome cancer-fighting force, with the potential to target every cancer cell in the body.” (See the video below)
“We have been using analysis to predict what sorts of mutations are present across the tumor, so we wondered whether we could use it to look for antigens shared on all tumor cells. We had suspected that the diversity of mutations we see in the tumo, evolution would be reflected by the antigens present on the cancer cells — but until now we had no proof.” -Dr. Nicholas McGranahan, researcher involved in the Cancer Research UK study.
Immunotherapy is a broad area of study and treatment that is accelerating. Current research has shown that 70 percent of patients dealing with multiple myelomas recovered better using immunotherapy. Several types of immunotherapies have been shown to improve and potentially cure melanomas including: B-cell chronic lymphocytic leukemia, non-hodgkin lymphoma and are being studied to treat almost every kind of cancer.
There is a broad variety of treatments that fall into the category of immunotherapy. One form of immunotherapy is know as immune checkpoint inhibitors which uses drugs to suppress the immune system’s ability to keep itself in balance during an immune response. This allows the body to release an explosive response to cancer when the normal balanced approach won’t be effective. This first FDA approved drug of this type is ipilimunab, also known as Yervoy, which is used to treat advanced melanoma.
The missing immunotherapy piece: Antigens
Researchers have found that the particular pattern of antigens could help find the most effective immunotherapy treatment. This would provide a much more precise treatment instead of the broad attack of general cancer therapies. They found this key through a several tests and a sequence of discoveries.
The initial step was using The Cancer Genome Atlas data which examined 200 patients who had lung caner if the form of adenocarcinoma or squamous cell carcinoma. It was found that the adenocarcinoma had a far more visible antigen pattern. This made it easier for the immune system to attack and patients generally did better then those with squamous cell. This was an effective antigen prediction tool which allows the immune cells to find similar antigens on cancer cells.
Another finding showed that tumors with a lot of antigens had a way of suppressing the immune system by using PD-L1, a molecule which turns off attacking immune cells. This is the tumors way of neutralizing the immune system’s normal attempts to destroy the cancer.
Lastly, another experiment identified one more important key. Examining data from a study on checkpoint inhibitor known as Keytruda showed that the drug turned off the tumor’s use of PD-L1. This means it stopped the immune surpassing effect of the tumor. They looked at the results of that study vs their antigen-prediction plan, which showed how their tumors display antigens. It was found that 12 of 13 patients who had shared antigens had better outcomes then those who had many different antigens.
In summary, it is clear that there are many precise points for immunotherapy treatments varying on tumor antigen expression. Treatments will need to be improved to allow them to be used mainly when tumor cells share multiple antigens.
“Since the true genetic complexity of a growing tumor began to be revealed a few years ago, we’ve all been scratching our heads trying to work out a way round it,” said Professor Charlie Swanton of the Francis Crick Institute, this may lead to “…truly effective treatments for advanced disease that exploit the underlying order in the chaos,” he adds. “It’s incredibly exciting, and although it’s early days, it offers hope that we might just be able to turn the tide against advanced cancer — something we desperately want for our patients.”
