Immunotherapy treatment is already approved by the U.S. Food and Drug Administration (FDA) for pleural mesothelioma. It’s not yet approved for peritoneal mesothelioma, though.
In a recent study, the immunotherapy drug Keytruda proved effective at extending survival for patients who cannot have surgery.
According to a study published on the JAMA Network website, the immunotherapy treatment led to a median survival of nearly 21 months. The average survival for peritoneal mesothelioma is 1-2 years when surgery is not an option.
There were 24 patients in the study. Most of them (96%, or 23 of the 24) had a previous cycle of intravenous chemotherapy. Two-thirds (16 of 24) underwent cytoreductive surgery. Despite these treatments, the cancer returned.
At a median follow-up time of 29 months, the median progression-free survival was 4.9 months and the median overall survival was 20.9 months.
What Is Keytruda?
Keytruda is an immunotherapy drug approved for the treatment of pleural mesothelioma. Keytruda is the brand name for the immunotherapy drug pembrolizumab. It’s an immune checkpoint inhibitor that blocks two proteins (PD-1 and PD-L1) from connecting.
PD-1 is a protein on the surface of our immune system’s T cells. PD-L1 is a protein on the surface of mesothelioma cells. When these two proteins link together, the immune system’s T cells shut down and stop looking for cancer.
Keytruda blocks interactions between PD-L1 and PD-1 proteins, preventing the binding of the two proteins. By blocking the interaction, T cells remain active and alert, ready to fight off mesothelioma.
The FDA’s approval of Keytruda for pleural mesothelioma is for a segment of patients with a high volume of the PD-L1 protein.
Keytruda Helps for Cases of Non-Epithelioid Peritoneal Mesothelioma
These survival rates are similar to immunotherapy for pleural mesothelioma. Opdivo and Yervoy, for instance, are two other immunotherapy treatments. They led to a median survival of 18 months for malignant pleural mesothelioma.
In the aforementioned study, patients with non-epithelioid cell type (biphasic cell or sarcomatoid cell) did better with survival:
- 31.8 months for non-epithelioid cell type
- 17.5 months for epithelioid cell type
Most patients had the epithelioid cell type diagnosis of peritoneal mesothelioma. Most were also not positive for the PD-L1 protein, which is what Keytruda blocks to help the immune system find the tumors. Still, the treatment was helpful for patients.
There were three patients with a progression-free survival of at least two years.
Sources & Author
- Clinical Outcomes Associated With Pembrolizumab Monotherapy Among Adults With Diffuse Malignant Peritoneal Mesothelioma. JAMA Network. Retrieved by: https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2802254. Accessed: 03/17/2023.
Sources & Author