Need to Combine Tremelimumab with Durvalumab for Mesothelioma

Immunotherapy for mesothelioma is most effective when a combination of two drugs are used to thwart two mechanisms of mesothelioma cells.

Another study confirms that durvalumab, another immunotherapy option for mesothelioma, works best when paired with tremelimumab.

A phase 2 study for patients with pleural mesothelioma tested durvalumab alone versus durvalumab with tremelimumab. Both groups received immunotherapy before aggressive surgery to remove the cancerous tumors.

The results show how durvalumab and tremelimumab working together is much better than them working alone.

 

How Do Durvalumab and Tremelimumab Work?

Durvalumab and tremelimumab are called immune checkpoint inhibitors. These types of immunotherapies block specific immune system-suppressing mechanisms of mesothelioma cells.

Mesothelioma cells express certain proteins that direct the immune system away from the cancer. These proteins are called PD-L1 and B7. They bind with proteins on T cells, which are soldiers of the immune system. T cells are responsible for defending the body against intruders, including cancer.

PD-L1 binds with the protein PD-1 on T cells, and B7 binds with CTLA-4.

Durvalumab blocks PD-1 from binding with PD-L1. Tremelimumab blocks B7 from binding with CTLA-4. When these immunotherapies separate the two pairs of proteins, the T cells remain active in their search for mesothelioma cells.

Durvalumab and tremelimumab are often paired together to treat cancer. In fact, the U.S. Food and Drug Administration has approved durvalumab and tremelimumab for lung cancer.

 

Study Results for Durvalumab and Tremelimumab

The study consisted of 20 patients: nine received just durvalumab while 11 received durvalumab and tremelimumab. All but three of the 20 patients underwent an aggressive mesothelioma surgery after immunotherapy treatment finished.

The median overall survival for patients receiving durvalumab and tremelimumab was much higher. Their median survival had not been reached at the 34-month follow-up point, meaning some of the patients were remarkably still alive. The median survival for patients receiving only durvalumab was 14 months.

The average survival for people with pleural mesothelioma is 12-16 months. Surgery can lengthen survival by one year.

The only concern with using both immunotherapy drugs was side effects. Durvalumab and tremelimumab together caused grade 3 or higher toxicities in 27% of patients (3 of 11), while durvalumab alone caused grade 3 or higher toxicities in 8% of patients.

However, top cancer centers can manage these toxicities and keep patients safe and comfortable. Additionally, studies show that side effects from immunotherapy treatment correlate to a longer survival, so experiencing toxicities could be a sign of effective treatment.

Each patient should decide what’s most important to them, but some feel improved survival is worth some discomfort during immunotherapy treatment.

Our team can provide more information about immunotherapy for mesothelioma, including how it works and where to find a treatment center. Email lead patient advocate and registered nurse Karen Ritter at karen@mesotheliomaguide.com for access to an expert.