A possible new drug for mesothelioma has received FDA approval for the treatment of advanced epithelioid sarcoma.
Tazemetostat (Tazverik) is an oral medication made by a company called Epizyme. It is a brand new kind of drug that blocks a protein called EZH2. Tazemetostat is in testing for several different types of cancer, including malignant mesothelioma.
The recent FDA approval is an encouraging sign that it could one day be a new drug for mesothelioma.
In Search of a New Drug for Mesothelioma
Malignant mesothelioma is one of the most serious consequences of exposure to asbestos. Once asbestos fibers get into the lungs and other tissues, they never leave. Their presence sets up a cascade of cellular reactions that can result in mesothelioma years later.
Mesothelioma patients have few viable treatment options. There has not been a new drug for mesothelioma since Alimta (pemetrexed) received FDA approval in 2004. Alimta is an antifolate that is also approved for non-small cell lung cancer. For most mesothelioma patients, chemotherapy with Alimta is the first treatment they receive.
Unfortunately, fewer than half of mesothelioma patients respond to Alimta. Patients who have chemotherapy with pemetrexed only live about four months longer than patients who do not. Researchers around the world are trying to come up with a new drug for mesothelioma that will be more effective.
What is Tazemetostat?
Tazemetostat is a cancer pill that is still in development. It inhibits a protein called EZH2. EZH2 helps embryonic cells differentiate into all different types of cells. In mature cells, EZH2 inhibits the genes responsible for suppressing the growth of tumors. Mutation or over-expression of EZH2 has been linked to many forms of cancer.
Tazemetostat is still a long way from becoming a new drug for mesothelioma. Its first FDA approval is for patients with advanced epithelioid sarcoma that cannot be removed surgically. The FDA granted Epizyme accelerated approval for tazemetostat in January based on the results of early clinical trials in people with this cancer.
In the 62 patients tested, nearly 15 percent responded to the drug. Sixty-seven percent of those patients had a response that lasted more than six months.
Tazemetostat for Malignant Mesothelioma
According to the company, “Tazemetostat has demonstrated clinical activity and a generally well-tolerated safety profile in both patients with hematological malignancies and genetically defined solid tumors.”
In order for it to become a new drug for mesothelioma, tazemetostat will have to produce similar results in mesothelioma patients.
Patients in the mesothelioma clinical trial all have BAP1 loss. BAP1 stands for BRCA associated protein-1. People who have an inherited BAP1 gene mutation face a higher risk for several conditions, including malignant mesothelioma. These patients may be more responsive to treatment with tazemetostat.
Hoy, SM, “Tazemetostat: First Approval”, March 12, 2020, Drugs, Epub ahead of print, https://link.springer.com/article/10.1007%2Fs40265-020-01288-x
“FDA approves tazemetostat for advanced epithelioid sarcoma”, January 24, 2020, https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-tazemetostat-advanced-epithelioid-sarcoma
Tazemetostat information page, Epizyme website, http://www.epizyme.com/programs/tazemetostat/