The use of certain immunotherapy drugs for mesothelioma is based on whether specific proteins are on the cancer cells.
A recent study proved peritoneal mesothelioma often has a protein that can be treated with a class of immunotherapy drugs called immune checkpoint inhibitors. The protein is called PD-L1. This protein makes cancer treatable with immune checkpoint inhibitors like Opdivo and Keytruda. These are also called checkpoint blockade immunotherapy drugs.
One of the authors in the study is Dr. Richard Alexander. He’s a peritoneal mesothelioma doctor at Rutgers Cancer Institute and one of the best experts for peritoneal mesothelioma. The information in the study may open more opportunities for immunotherapy treatment for peritoneal mesothelioma.
Explaining How PD-L1 Affects Mesothelioma Treatment
PD-L1 is an immune checkpoint protein. It binds with a protein on T cells called PD-1. T cells are immune system cells supposed to fight cancer.
When the two proteins bind together, the T cells do not attack cancer cells. The PD-L1 protein essentially tricks the T cells.
Opdivo, the brand name for nivolumab, is a PD-L1 immune checkpoint inhibitor drug. Keytruda, the brand name for pembrolizumab, is another PD-L1 blockade immunotherapy drug.
Opdivo is approved by the FDA for many cases of pleural mesothelioma, which forms in the lining of the lungs (the pleura). This type of cancer expresses PD-L1 at high volumes, which makes it prone to treatment with PD-L1 blockades. Patients can receive Opdivo and a different type of immune checkpoint drug called Yervoy, which blocks the proteins B7 and CTLA-4 from binding.
The question for researchers and mesothelioma doctors has been whether peritoneal mesothelioma also expressed PD-L1. The answer would determine whether it was treatable with Opdivo, Keytruda and other similar immunotherapies.
Most Peritoneal Mesothelioma Tumors Have PD-L1
There were 21 samples obtained from peritoneal mesothelioma patients for the study. Sixteen of the 21 (76%) were positive for PD-L1 after histology staining. As the volume of PD-L1 increased, researchers noticed the survival worsened.
A few clinical trials are investigating use of immunotherapy for peritoneal mesothelioma. A trial at MD Anderson Cancer Center in Houston, Texas, used atezolizumab and bevacizumab. Exactly 80% of the 20 enrolled patients lived for at least one year from starting the treatment.
A clinical trial at the University of Chicago Medicine is exploring Opdivo and Yervoy prior to cytoreduction and HIPEC surgery. This surgery is the preferred way to treat peritoneal mesothelioma. Combining immunotherapy with it may help survival even more.
You may be eligible to join this trial or another one for peritoneal mesothelioma. Talk with our lead patient advocate and registered nurse about immunotherapy for this type of mesothelioma. Karen Ritter is available by email at email@example.com.
Sources & Author
- Expression of PD-L1 in Patients With Malignant Peritoneal Mesothelioma: A Pilot Study. Journal of Surgical Research. Retrieved from: https://pubmed.ncbi.nlm.nih.gov/35489218/. Accessed: 07/02/2022.
Sources & Author