A phase II clinical trial comparing anetumab ravtansine to the chemotherapy drug vinorelbine did not have promising results for treating mesothelioma like researchers had hoped. Anetumab ravtansine is an immunotherapy drug that is a monoclonal antibody, which is an engineered antibody that can be used to fight cancer. Researchers found that anetumab ravtansine did not improve the overall survival or progression free survival of mesothelioma patients. The study was performed at the University of Chicago and looked at pleural mesothelioma patients whose cancer had relapsed after treatment. Once someone’s pleural mesothelioma reoccurs after treatment, the person only has a few months of survival left.
Anetumab ravtansine is a monoclonal antibody, which is a protein made in a laboratory that sticks to specific targets like antigens on cancer cells, helping the immune system. Anetumab ravtansine is specifically made to target mesothelin, which is a protein that can be found on mesothelioma cells. The antibodies bind to mesothelin on mesothelioma cells, preventing them from dividing and growing out of control. This can help prevent cancer development.
Cells naturally die, which is called apoptosis. Before this happens, they replicate to maintain a healthy level of cells. Cancer cells usually do not undergo apoptosis, so when they replicate, they can grow out of control and form tumors. Anetumab ravtansine fixes this by entering cells and releasing a cytotoxic agent called DM4, killing the cells that express mesothelin.
Mesothelioma patients did not improve when they were administered anetumab ravtansine. There were 248 patients in the study who either received anetumab ravtansine or vinorelbine chemotherapy. The chemotherapy group received 30 mg/m2 once a week while the immunotherapy group received 6.6 mg/kg2 once every three weeks. Vinorelbine is a proven good option for relapsed mesothelioma patients, but it is not currently approved for the use on mesothelioma patients. Survival can be improved to four to five months after relapse
There were less serious side effects for the immunotherapy groups, which is a positive aspect of the treatment. There were 48 percent of patients who received mild or severe side effects when they were administered anetumab ravtansine versus 74 percent of patients who were administered vinorelbine. The most common side effect for patients who took anetumab ravtansine was difficulty breathing while neutropenia was the most common side effect for the vinorelbine patients. Grade three pneumonia occurred in four percent of monoclonal antibody patients while it occurred in seven percent of vinorelbine patients. Even though the monoclonal antibody treatment was not found to be effective by itself, it is possible that this treatment could be useful if combined with another treatment.
Source:
Matthew Stanger, “Anetumab Ravtansine vs Vinorelbine in Relapsed Mesothelin-Positive Advanced Malignant Pleural Mesothelioma” Ascopost (May 10). [Link]
