Two medical researchers, James Allison of the U.S. and Tasuku Honjo of Japan, were awarded the Nobel Prize for medicine this week for their breakthrough research in harnessing the body’s own immune system to fight cancer.
Allison and Honjo’s breakthroughs came way back in the 1990s. Their research eventually led to the production of immunotherapy drugs such as Yervoy in 2011 and later the well-known drug Keytruda.
Immunotherapy unleashes the body’s own immune system to attack cancer cells rather than chemotherapy. It tends to not have as many side-effects as chemotherapy and for certain kinds of cancers, such as melonoma, it has provided astounding results. Keytruda is most famous for being known as “The Jimmy Carter” drug because Carter was given the drug on an experimental basis several years ago when he had advanced melanoma and brain cancer. And Jimmy is still around today to talk about it.
Keytruda has shown success in treating certain kinds of small cell lung cancer (if patients have certain gene markers). While there are some reports that people with melanoma have been literally cured by Keytruda, it’s not a cure for lung cancer. However, for some patients, they live much longer on the average than with traditional chemo and have much better quality of life.
From a Scientific American article:
Allison, a professor at The University of Texas M. D. Anderson Cancer Center in Houston, discovered that a molecule called CTLA-4 (cytotoxic T-lymphocyte antigen 4) acts as a “brake” on the immune system; remove the brake and—in many cases—immune cells are unleashed to fight the cancer. Allison spent 17 years convincing others that this approach could work, leading to approval in 2011 of the drug Yervoy, which showed near-miraculous results for a fraction of patients with a lethal form of skin cancer.
The pharmaceutical industry is vigorously pursuing immunotherapy, and hundreds of trials are currently underway based on CTLA-4, PD-1 and other immune approaches.
For decades researchers had been trying to figure out effective ways to use the body’s own immune system against cancer. They tried vaccines and other approaches for ramping up immune activity. Allison’s insight, Perlmann said, was to trigger the brakes instead. “It represents a completely new principle because, unlike the previous strategies, it is not based on targeting the cancer cells but rather the brakes, the checkpoints of the host immune system,” he said. “It represents a paradigmatic shift and a landmark in the fight against cancer.”
Honjo’s research was completely separate from Allison’s, but used a similar approach.
From the article:
Meanwhile Honjo, of Kyoto University in Japan, was studying a different immune brake called PD-1 (programmed cell death 1), according to Thomas Perlmann, secretary general of the Nobel Committee, who spoke about the findings amid the prize announcement early Monday. Allison’s success with CTLA-4 in cancer persuaded Honjo to consider his molecule in cancer as well—and he found PD-1 therapy was even safer and more effective against a number of cancers, including lung cancer, which kills about 150,000 Americans a year. Drugs based on his findings also work in combination with Yervoy against a number of types of cancer.
Keytruda is not quite a miracle drug, unfortunately. Not everyone has the gene markers for it, but it has gained a massive reputation thanks to Jaimmy Carter. From a Times Now article:
While in theory it should work for most forms of cancer, it’s most effective on those with the highest numbers of mutations such as melanomas, lung cancer and smoking, he added.
And it has sometimes been met with too much enthusiasm by patients. In the US, some have reportedly asked their doctors to immediately use immunotherapy instead of traditional treatments like chemotherapy, even when they are more effective.
After his big win on Monday, Allison warned that immunotherapy will not replace all other cancer treatments. Instead, it is “going to be part of therapy that potentially all cancer patients will receive in five years,” he told a press conference in New York. Honjo, meanwhile, said he wanted to continue his research “so that this immune therapy will save more cancer patients than ever”.