Straight Talk about Mesothelioma, a blog series created by Michael T. Milano, M.D., Ph.D., a radiation oncology specialist, as a resource for mesothelioma patients and their loved ones.
While chemotherapy and surgery are among the most common treatment methods for mesothelioma, immunotherapy drugs are now being tested as a potential alternative or supplement to standard chemotherapy.
One of the largest immunotherapy trials to date, which is being conducted in France, suggests these drugs may have some advantages over standard treatment regimens.
New Mesothelioma Cases Call for New Approaches to Care
The deadly cancer mesothelioma is exclusively caused by exposure to asbestos, and incidents have been on the rise in recent years. Mesothelioma is a particularly devastating disease, since after diagnosis patients live only 13-15 months on average. Chemotherapy does not provide prolonged control of mesothelioma, and the cancer regrows after a duration of time, often in less than half a year. Thus, alternative mechanisms are needed to slow its progress.
A recent study conducted at several treatment facilities in France involved 125 patients whose cancer had resumed growth after 1 or 2 rounds of chemotherapy. These individuals were given either the immunotherapy drug nivolumab, or a 2-drug combination of nivolumab and ipilimumab, until the tumors began spreading again. About 70 percent of those involved with the study were able to have at least 3 rounds of these drugs.
After a treatment period of 12 weeks, the cancer had not worsened in 44 percent of patients who were taking only nivolumab, and in half of the patients taking nivolumab and ipilimumab. This is better than the typical response rate of 30 percent with most chemotherapy regimens.
Additionally, in 17 percent of patients who were given nivolumab and in 26 percent of the patients given nivolumab and ipilimumab, the mesothelioma tumors became smaller. Researchers continued to track the patients after immunotherapy, and found that on average the tumors started growing again after 4 months for patients on nivolumab, and after 5.6 months for patients who took nivolumab and ipilimumab.
The latter group also experienced more side effects, such as skin rashes and colon inflammation, but in general these problems were not very severe.
How Immunotherapy Works
Additional studies of these and other drugs are underway, as researchers investigate whether immunotherapy would be an effective treatment after surgery and chemotherapy, or even before. The negative aspect of chemotherapy is that while it kills cancer cells, it also kills noncancerous cells. At the same time, mesothelioma is very difficult to combat since the tumors protect themselves against the body’s immune system.
Mesothelioma cells have checkpoints, or proteins on the cell that prevent white blood cells system from attacking them. Many of the newer immunotherapy drugs are checkpoint inhibitors, since they stop the proteins from deterring the white blood cells. Researchers are now testing a few different kinds of immunotherapy drugs, because mesothelioma has several checkpoint inhibitors.
While immunotherapy is not certain to work for all patients, the range of drugs now being tested may help doctors find the best combination for different types and stages of mesothelioma. This growing knowledge about the deadly disease is moving us forward in our understanding of mesothelioma and how to slow it, with every step getting us closer to more effective treatment protocols, and perhaps a cure.