Clapper, Patti, Schweizer and Mason

Research continues into immunotherapy that targets specific proteins as an effective treatment for mesothelioma.  Researchers have long understood that the presence of abnormally high levels of mesothelin, a protein that’s expressed on the surface of cells, is associated with the presence of malignant mesothelioma.  Several tests have been developed as preliminary diagnostic tools for potential mesothelioma patients that revolve around serum levels of mesothelin (the levels of the protein in free-flowing blood.) Several current studies are experimenting with using mesothelin as a target for various agents in hopes to discover a more effective treatment than currently exists.

Immunotherapy is a relatively new discipline in which scientists find ways to either assist the body’s own immune system or fool it into attacking specific cells that it would otherwise ignore.  A clinical trial  for mesothelioma reported in the August bulletin of the National Cancer Institute (NCI) centered on a mesothelin-targeted treatment which revolved around Adoptive Cell Transfer, or ACT.

This type of therapy involves the harvesting of T Cells, a naturally occurring white blood cell that plays multiple roles in the chorus of a healthy immune system.  These cells are then replicated in a laboratory environment and then these large doses of a patient’s own cells are then returned to the body where it is hoped their numbers will overwhelm cancer cells. 

Dr. Steven Rosenberg postulated that it would be possible to build on this ACT therapy by actually altering T Cells to specifically target mesothelin.  This would effectively make those T Cells hunter-killers specifically honing in on cells with higher than normal levels of mesothelin, such as mesothelioma cells. 

Rosenberg’s research has progressed to the clinical trial stage.  During the first round of studies, patients will be monitored in a hospital environment and be treated for up to two weeks.  They will have their own T Cells harvested, altered in a laboratory, and then re-injected.  There is no real precedent for this type of study with mesothelioma patients though the theory is sound.  Rosenberg expects that the study, which is currently enrolling volunteers, will take up to six years to complete. 

If the results are as hoped, this trial may indeed lead to a new type of treatment for mesothelioma and other cancers that express mesothelin.  This new treatment could be used in conjunction with chemotherapy but would share none of the side effects.  Because this treatment involves the body’s own immune system and uses mesothelin as a very specific target, normal cells would not be affected.  This means that treatments could progress without the negative side effects of chemotherapy or radiation therapy.

Source: Treating Cancer With Anti-mesothelin Modified Lymphocytes