Immunotherapy Showing Promise for Brain Metastases

As I have mentioned a few times in this blog, melanoma has a disconcerting tendency to spread to the lungs, liver, and brain when it enters into the metastasizing stages. And brain tumors like that are pretty darn hard to treat. Most of the current treatments don’t really provide much benefit to patients. And once melanoma metastasizes, only about half of the patients survive more than a year.

The rise of immunotherapy may help to change that. Immunotherapy helps boost the body’s own immune system in a targeted fashion. Over the past decade or so, researchers have been honing in on treatments that may increase the effectiveness of this type of treatment in relation to melanoma.

In a recently published study, researchers from Brigham and Women’s Hospital in Boston, MA reviewed data on 2,753 U.S. patients who were diagnosed between 2010-2015 with Stage 4 melanoma that had metastasized to the brain. They found that “checkpoint blockade immunotherapy” doubled median overall survival.

What is “checkpoint blockade immunotherapy”? Basically it’s the use of drugs called immune checkpoint inhibitors. These drugs block specific proteins created by the body’s immune cells and some cancer cells that effectively put the brakes on your killer T cells. How? OK, by way of example, on a T cell there is a protein called PD-1. This protein keeps your immune system from running rampant. However, in some cases of cancer, the cancer cells play a nasty trick by producing a protein called PD-L1, which binds with PD-1. This action prevents the T cells from killing cells, including cancer cells. An immune checkpoint inhibitor (anti-PD-L1 or anti-PD-1) blocks this binding process, which then allows the T cells free rein. In other words, blocking either one of these proteins unleashes the immune response in the body, making it easier to find and kill the tumor cells.

Getting back to the results of the study… Those who were treated with checkpoint blockade immunotherapy had a median survival of 12.4 months, versus 5.2 months for those who did not receive immunotherapy. That’s more than twice as long. Put it another way, slightly more than 28% of the people who received immunotherapy were alive 4 years later compared to just 11% of the other group who didn’t get that treatment. Which group would you rather be in?

The researchers noted that the benefit was “even more dramatic” for people whose melanoma had spread only to the brain (one location) and not to additional locations, such as the liver or the lungs. There’s obviously lots more research to be done, but these types of treatment options are building more and more evidence that immunotherapy works and it is worth funding research to develop it further.