According to a story from Oral Cancer News, a class of immunotherapy drugs called immune checkpoint inhibitors can play a critical role in treating a number of common and rare cancers, particularly when metastasis has begun (the spreading of cancer to other areas). However, when doctors prescribe these drugs to patients, they often must do so with only limited certainty that they will work. However, the latest research has uncovered a method that can help predict if these drugs will be effective or not.
Immunotherapy and Tumor Mutational Burden (TMB)
In a recent study released in Nature Genetics, a team of scientists found that a measure called tumor mutational burden (TMB) can help doctors predict how well a patient will respond to immune checkpoint inhibitors. When patients failed to respond to immunotherapy, doctors didn’t really have a good explanation for patients, but the study found that tumors that had a greater number of mutations and DNA alterations were more likely to be affected by immune checkpoint inhibitors.
Study Results
There was some understanding that TMB could be used to predict response for patients with melanoma and certain lung cancers, but this larger study shows that it is applicable for many others as well. This research involved DNA from 1,662 patients with advanced cancer that had been treated with immune checkpoint inhibitors and DNA from 5,371 patients who had not been treated with these drugs.
The researchers determined that the top 20 percent of cases who had the most mutated tumors responded better to these drugs in comparison to the rest of the data sample.
With that being said, there were a few types of cancer where response did not improve with increased TMB. The scientists found that there was no correlation gliomas, a type of tumor that originated in glioma cells found in the brain or spine. TMB also did not predict response in patients with breast cancer. However, there were relatively few breast cancer patients in the study and immune checkpoint inhibitors are not a common treatment for breast cancer in the first place.
This larger scale study provides more solid evidence that TMB can predict response to immune checkpoint inhibitors for most types of cancer in which they may be used. Check out the original study here.
