International Study Confirms Keytruda Improves Mesothelioma Life Expectancy

Keytruda, an immunotherapy for mesothelioma, improved the survival of pleural mesothelioma patients in an international phase 3 clinical trial. The study confirms Keytruda can benefit patients by extending their life expectancy.

The study, which tested Keytruda and chemotherapy together for mesothelioma compared to chemotherapy alone, was held in three countries: Canada, France and Italy. The study included 440 patients across 51 hospitals and is one of the largest studies ever held in the world to test Keytruda for mesothelioma.

In the clinical trial, the 440 patients were nearly evenly split between the two groups: Keytruda combined with chemotherapy; and chemotherapy alone. Patients who received Keytruda had a median survival of 17.3 months. Patients who didn’t receive Keytruda had a median survival of 16.1 months.

Other statistics were:

• 25% 3-year survival rate for the Keytruda group
• 17% 3-year survival rate for the chemotherapy group

Patients who received Keytruda had more adverse events than those who didn’t receive the immunotherapy. However, most of the adverse events were manageable side effects of immunotherapy, and only 18% of the patients who received Keytruda were admitted to a hospital for serious side effects.

“In patients with advanced pleural mesothelioma, the addition of pembrolizumab to standard platinum–pemetrexed chemotherapy was tolerable and resulted in a significant improvement in overall survival,” the study authors wrote.

 

What is Keytruda?

Keytruda is the brand name of the drug pembrolizumab. It is an immunotherapy that blocks the activity of a specific protein on T cells and cancer cells. This type of immunotherapy is called an immune checkpoint inhibitor.

Immune checkpoint inhibitors like Keytruda block the linking of a protein on T cells and mesothelioma cells. T cells have a protein called PD-1, and mesothelioma cells contain a protein called PD-L1.

These two proteins connect, which tells the T cells to “stand down” and not attack the mesothelioma cells. It’s a trick the cancer cells use to make the T cells think they’re normal, healthy cells.

Immune checkpoint inhibitors block the two proteins from connecting. The drug creates a wall that separates the two proteins, which allows T cells to correctly identify mesothelioma cells with PD-L1 as dangerous to the body.

 

Is Keytruda Approved for Mesothelioma in the United States?

Keytruda is approved by the U.S. Food and Drug Administration (FDA) for a small group of patients with malignant pleural mesothelioma. The patients must have a specific genetic mutation and a high volume of PD-L1 proteins expressed by the cancer cells.

Pleural mesothelioma is the most common type of mesothelioma cancer. It forms in the small lining of the lungs, and the only known cause is exposure to asbestos. Approximately 80% of people with mesothelioma have this type.

Keytruda is one of a few immune checkpoint inhibitors approved for or tested for mesothelioma. Others are:

• Opdivo (nivolumab), which is FDA-approved for malignant pleural mesothelioma
• Yervoy (ipilimumab), which is FDA-approved for malignant pleural mesothelioma
• Imfinzi (durvalumab), which is not approved but has been in several clinical trials

Keytruda is not yet approved for malignant peritoneal mesothelioma, but there have been several studies testing it in patients. Peritoneal mesothelioma forms in the lining of the abdominal cavity, and approximately 20% of patients have this type.

Patients in the U.S. diagnosed with pleural mesothelioma can receive immunotherapy for their cancer. If you have mesothelioma or your loved one has been diagnosed, please contact our patient advocates to learn about treatment and where to find a doctor who specializes in this cancer. Email our patient advocate and registered nurse Karen Ritter at karen@mesotheliomaguide.com.