Non-Epithelioid Mesothelioma: Immunotherapy Combo Could be the New Standard of Care

Two immunotherapy drugs could become the new standard of care for people with non-epithelioid mesothelioma. 

All forms of malignant mesothelioma are deadly. But people with a non-epithelioid mesothelioma subtype are less likely to respond to standard treatments. Their variety of mesothelioma is especially resistant to chemotherapy with cisplatin and Alimta. This has been the mainstay of pleural mesothelioma treatment since 2004.

But a new trial shows two immunotherapy drugs extended mesothelioma survival better than chemotherapy. This could be especially good news for patients with non-epithelioid mesothelioma. 

Checkpoint Inhibitors for Mesothelioma

Most people with pleural mesothelioma start with chemotherapy. Chemotherapy can often extend life by a few months. It is most beneficial for patients with epithelioid mesothelioma.

But this approach does not work as well for non-epithelioid mesothelioma. Data presented this week at IASLC’s World Conference on Lung Cancer suggests these patients may have another option. 

The new treatment combines two checkpoint inhibitors. Nivolumab (Opdivo) and ipilimumab (Yervoy) complement each other. They activate the immune system and help keep mesothelioma cells from escaping attack. 

Comparing Chemotherapy & Immunotherapy

The Phase 3 trial is called CheckMate-743. It included 303 patients with epithelioid or non-epithelioid mesothelioma. All patients were inoperable and had not yet had any treatments. 

One group of patients received chemotherapy with cisplatin and pemetrexed (Alimta). Another group received immunotherapy with Opdivo and Yervoy.

For the first eight months, patients in the chemotherapy group seemed to do better. But then the paths switched. At 12 months, 68 percent of the immunotherapy patients were still alive. Fifty-eight percent of the chemotherapy patients were alive. 

At two years, 41 percent of the immunotherapy group was alive, compared to 27 percent of the chemotherapy group. 

Non-Epithelioid Mesothelioma Patients Benefited Most

Immunotherapy was especially helpful for non-epithelioid mesothelioma patients. These patients had an overall survival of just 8.8 months with chemotherapy. Epithelioid mesothelioma patients in the chemotherapy group lived for more than 16 months. 

Lead Investigator Paul Bass, MD, PhD, of the Netherlands Cancer Institute says nivolumab and ipilimumab “should be considered as a new standard of care” for patients with non-epithelioid mesothelioma. 

Both groups of patients had about the same number of serious complications. Three of the immunotherapy patients died as a result of the treatment. One of the chemotherapy patients died. 

This is the first randomized trial of dual immunotherapy as a first-line treatment for pleural mesothelioma. 

Sources:

“Opdivo (nivolumab) Plus Yervoy (ipilimumab) Demonstrates Durable Survival Benefit vs. Chemotherapy in Patients with Previously Untreated Malignant Pleural Mesothelioma”, Bristol Myers Squibb, Press Release, August 8, 2020, https://news.bms.com/press-release/corporatefinancial-news/opdivo-nivolumab-plus-yervoy-ipilimumab-demonstrates-durable-s

Fowler, Matthew, “Nivolumab Plus Ipilimumab Improves OS in Malignant Pleural Mesothelioma”, August 10, 2020, Cancer Network, https://www.cancernetwork.com/view/nivolumab-plus-ipilimumab-improves-os-in-malignant-pleural-mesothelioma