For years, researchers have been trying to find a way to tackle cancer.
While surgery and radiation have helped some, those in advanced stages or other specific types of cancers have not seen positive results.
The idea of using the body's own immune system to fight the disease has been proposed for some time. However, it was the pioneering work of Professor James P. Allision of the U.S and Professor Tasuku Honjo of Japan that led to the creation of new drugs to fight cancer.
For their contribution to the world of medicine, the two were awarded the Nobel Prize in Physiology and Medicine last week.
The Immune System
Let's understand how the immune system works. When we fall ill from a viral (or bacterial) infection, our immune system steps up to defend our body.
When there is an infection, T-Cells are deployed to the site of the infection where they detect and destroy the virus-infected cells. T-Cells are a type of white blood cells that are always circulating in our bodies. These killer T-Cells are assisted by helper T-Cells that coordinate the attack and send chemical messages asking the killer T-Cells to multiply.
In the case of cancer, scientists observed that the immune system was not involved and therefore was not assisting the body in fighting the tumor cells. They realized that cancer cells were somehow putting a brake on the killer T-Cells and making them ineffective.
Understanding Cancer Cells
Professor Allison noticed that a protein known as CTLA-4 prevents the T-Cells from attacking the cancerous cells.
He then created an antibody (a protein) that could bind with the CTLA-4 so that it no longer inhibited the T-Cell's function. This antibody was injected into mice with cancer and resulted in cancer-free mice. After the successful experiments on mice, Allison injected the same antibody into humans with melanoma skin cancer, and the results were favorable.
Meanwhile, Professor Honjo discovered another protein, PD-1, which also acts as a brake and prevents the T-cell from doing its job. PD-1, however, uses a different mechanism. Antibodies that could turn off the PD-1 protein were found to be even more effective in different types of cancer (including the deadly lung cancer) and patients appeared to be in long term remission.
New studies show that combining the two strategies may be the best approach to fighting cancer. Thanks to efforts by Allison and Honjo, a new class of cancer-fighting drugs have been introduced in the market. This kind of therapy that uses drugs to assist our body's natural immune system is known as Immune Checkpoint Therapy.
Despite producing fantastic results, the solution does not work for all types of cancer and some patients have reported side effects. Regardless, the winners of the 2018 Nobel in Medicine have transformed the way researchers approach the search for a cure for cancer.
Sources: Nature, ASU.edu, Sciencemuseum.org, BBC, Nobelprize.org