Frontiers in Oncology provisionally accepted a case report Friday suggesting the use of first-line nivolumab and ipilimumab could be more effective than chemotherapy in malignant peritoneal mesothelioma (MPM) treatment. 

A team of researchers working in France reported a 74-year-old woman with MPM had a “major and sustained 12-month response” to the anti-PD-1 nivolumab and the anti-CTLA 4 ipilimumab. 

“Our findings suggest a role for ICI in non-resectable diffuse MPM exhibiting PD-L1 overexpression and loss of BP1 expression, and install new hope in their treatment,” the report stated. 

The researchers believe this is only the second recorded case of a major clinical response to the use of dual immunotherapy as a treatment for malignant pleural mesothelioma. 

Types of Peritoneal Mesothelioma Treatment 

Mesothelioma, a form of cancer whose only known risk factor is asbestos exposure, usually originates in the lining of the lungs. This variant of the disease is called pleural mesothelioma. However, peritoneal mesothelioma affects the membrane around the digestive tract. The prognosis is poor for both these variants, but peritoneal mesothelioma is studied even less because it is so rare.

Peritoneal mesothelioma patients can undergo surgery to remove tumors. Although it has proven successful when combined with chemotherapy, the procedure is incredibly invasive. Sometimes the peritoneum must be removed. In some cases, parts of the structures that the peritoneum adheres to, such as the ovaries, uterus and gall bladder, and even parts of the intestines are removed.

Another treatment option is chemotherapy. It isn’t very effective by itself when used for mesothelioma patients, but it works better in combination with surgery and/or radiation treatments. 

Immunotherapy is the Next Wave of Treatment

Immunotherapy is a promising new frontier in mesothelioma treatment. Its goal is to stimulate the body’s immune system to destroy mesothelioma cancer cells. 

Some immunotherapy drugs target proteins that inhibit the body’s natural ability to fight cancer. Other drugs, such as nivolumab and ipilimumab, use antibodies instead. The FDA approved the use of those two medications in 2020 to treat some patients with malignant pleural mesothelioma who either didn’t respond to surgery or weren’t surgical candidates. 

A 2021 study showed an overall 23.5% survival rate in malignant pleural mesothelioma patients given nivolumab. However, research into how nivolumab might help those with peritoneal mesothelioma has lagged behind. That’s why the case report published Friday is a crucial next step in helping these patients live longer.