New research conducted by a team of German and Austrian scientists could help make personalized immunotherapy for mesothelioma possible.
Mesothelioma is an incurable cancer caused by exposure to asbestos. Immunotherapy is one of the most promising treatment approaches.
But immunotherapy drugs like Keytruda do not work for all patients. Scientists do not know exactly why this is. The new study suggests that understanding biomarkers could lead to better outcomes through personalized immunotherapy for mesothelioma.
How Does Immunotherapy Work?
Immunotherapy is a broad term that means using the patient’s own immune system to fight their cancer. There are many different types of immunotherapy. Some involve stimulating an immune response. Others involve turning off the mechanism that lets mesothelioma cells hide from the immune system.
That is how Keytruda (pembrolizumab) works. Keytruda is an immune checkpoint inhibitor. It represents a step toward personalized immunotherapy for mesothelioma. Only patients with a certain kind of gene expression respond to Keytruda.
Patients with higher levels of the protein PD-L1 on their cells can take Keytruda, but it does not work for all of them. Other immunotherapy drugs being tested for mesothelioma include Yervoy and Opdivo. None of them have been FDA-approved specifically for mesothelioma.
Toward More Personalized Immunotherapy for Mesothelioma
The new Austrian study focuses on PD-L1 as a path toward personalized immunotherapy for mesothelioma. Other studies show mesothelioma patients with high PD-L1 expression do not live as long as other patients. The scientists wondered what role biomarkers like PD-L1 play in prognosis and now that could impact treatment.
They looked at the levels of PD-L1, C-reactive protein (CRP) and Ki-67 protein in 123 cancer patients. CRP and Ki-67 influence cancer growth and spread.
“Interestingly, Ki-67 index and CRP influenced the prognostic power of PD-L1,” the authors write.
Patients on an immune checkpoint inhibitor like Keytruda lived longer. But among these patients CRP had more influence on survival than PD-L1 level did. Knowing that could help doctors create personalized immunotherapy for mesothelioma.
“In summary, histological and circulating biomarkers should also be taken into account as potential biomarkers in immune checkpoint inhibitor therapy and they may have an impact on the prognostic power of PD-L1,” they write.
Malignant pleural mesothelioma is usually fatal within a year, even with the best standard cancer treatment. Personalized immunotherapy for mesothelioma could change the outlook for the 2,500 Americans diagnosed each year.
Ghanim, B, et al, “Tumour Cell PD-L1 Expression Is Prognostic in Patients With Malignant Pleural Effusion: The Impact of C-reactive Protein and Immune-Checkpoint Inhibition”, April 1, 2020, Scientific Reports, https://www.nature.com/articles/s41598-020-62813-2