Immunotherapy is a growing area of research in the treatment of all types of cancer. But for mesothelioma, which is among the most difficult cancers to manage, treat, or cure, these new therapies that harness the immune system are especially promising. They are offering new hope to patients diagnosed with this deadly, asbestos-related cancer. The most recent research is showing that a potent combination of a vaccine and chemotherapy could have good results for mesothelioma patients.
The TroVax Vaccine
A vaccine is biological material that is injected into a person to stimulate the immune system to fight back against a particular pathogen. Vaccines have traditionally been used to prevent transmission of viral diseases like the flu, but they are now being developed to treat cancer.
A cancer vaccine works by training the immune system to recognize and kill cancer cells. These cells have substances on their surfaces called antigens. Immune cells recognize antigens, but they need to be coached to do so. Vaccines that treat cancer maybe general, but they can also be made to target the specific antigens and cells in an individual patient.
A new vaccine called TroVax has been developed specifically for mesothelioma patients. It is a virus that has been genetically engineered to target a protein called 5T4 that is found in the cells of most mesothelioma tumors. Even the types of mesothelioma that are the most difficult to treat usually contain this protein.
Phase II Clinical Trial
TroVax has recently been tested in clinical trials. These are studies of new drugs or therapies in human patients. With TroVax, the results were promising. The researchers found that it could control cancer in 87 percent of participants with mesothelioma. In 17 percent of the patients, tumors were actually reduced in size.
The trial researchers did not just use the new vaccine in participants, though. The vaccine was given two weeks prior to regular chemotherapy using cisplatin and pemetrexed. As compared to patients who only received chemotherapy, those who got the vaccine as well had a greater chance of living longer. Eight patients in the study were still living after 24 months, a result significantly better than what is seen with chemotherapy treatment alone.
Mesothelioma is very challenging to treat, and chemotherapy is the only approved treatment for it. Clinical trials like the one with TroVax are attempting to find and test therapies that can improve upon the success rates of traditional chemotherapy.
With mesothelioma, surgery is often not a treatment option, making chemotherapy the best and most effective choice for extending life. Even so, most patients don’t live longer than 18 months after diagnosis. By adding other kinds of therapies to chemotherapy, researchers hope to improve those odds.
The phase II clinical trial for TroVax was considered successful, but it is not the end of the research. TroVax will likely be moved into phase III trials, now that researchers know it is relatively safe and may provide a good solution for mesothelioma patients. Current patients will have to wait a while for this treatment to become approved, but in the meantime they can look for this and other clinical trials to join.