Treatment for pleural mesothelioma is reaching a turning point. For years, the only strategies with curative potential have been surgery and chemotherapy. Surgery has been especially important for extending life expectancies, but not all patients can benefit from surgery—it has little effect on those whose cancer has spread.
A lot of patients aren’t diagnosed with mesothelioma until their disease is advanced. In these situations, it’s up to the mesothelioma specialist and patient to decide on the best treatment plan. Researchers have recognized the need for more comprehensive, specialized treatments, and after years of clinical studies, several treatments may fill this role.
A report published online last month reviewed three promising treatments with the most likelihood to change the way mesothelioma patients are treated. The report, “Malignant pleural mesothelioma: New hope in the horizon with novel therapeutic strategies,” highlighted the burgeoning value of drugs that block the development of cancer stem cells, inhibit blood vessel growth in tumors and use the immune system to fight cancerous cells.
Targeting Mesothelioma Stem Cells
Last year, a new clinical trial was announced for patients who had already been treated with standard chemotherapy. The trial tested defactinib, a drug seen as a likely maintenance therapy for mesothelioma patients. Early evidence has shown encouraging survival rates in patients given the drug.
The theory behind this treatment is that cancer stem cells that aren’t eliminated during standard treatment can develop a resistance to chemotherapy. Doctors believe mesothelioma tumors won’t be able to continue growing by killing cancer stem cells, which starts with blocking FAK. This would allow patients to “maintain” the stability of their disease and live longer without it progressing.
The Phase I trial of defactinib was a success, proving it is safely tolerated in patients. Phase II studies are currently underway.
Cutting Off the Blood Supply to Tumors
Another angle researchers are taking toward treating mesothelioma is cutting off the blood supply to tumors. Blood vessels grow in and around mesothelioma tumors supplying them with the nutrients necessary to spread. The growth of blood vessels is known as angiogenesis.
There are a couple different angiogenesis inhibiting drugs in clinical trials. These drugs hold the most benefit for patients with advanced mesothelioma for whom treatment options are limited.
This drug gets its name from the proteins it blocks from signaling blood vessel growth. Already in Phase III clinical trials, NGR-hTNF is proving to have an excellent effect on survival rates in relapsed patients.
Combining standard chemotherapy and anti-angiogenic drugs may have a stronger effect than chemo alone. The angiogenesis inhibiting drug cediranib is being evaluated in over 150 locations across the United States.
Activating the Immune System
Treatments that work with the immune system to fight mesothelioma are on the rise. There are multiple immunotherapy treatments proven to be effective in other types of cancer that are now being tested in mesothelioma.
A good example of a recently developed immunotherapy is CRS-207, which uses a genetically altered bacteria to incite an attack by the immune system on mesothelioma cells.
Dr. Robert Cameron, one of the foremost authorities on mesothelioma, argues for an approach to treatment using “long-term maintenance therapy utilizing immunotherapy and a combination of other conventional and experimental treatments designed to stop the recurrence of the tumor.”
Dr. Cameron and his team favor an immunotherapy drug called interferon, which has been prescribed successfully in many patients for a number of years. Immunotherapy drugs like these allow doctors to treat mesothelioma as a chronic disease by preventing it from spreading.
In the video below, Dr. Cameron explains why he takes a maintenance approach to treating his patients and how it has been successful.
Embracing the Future
Each of these approaches to mesothelioma treatment could possibly change mesothelioma treatment forever. Many patients who participated in clinical trials have already reaped the benefits. Mesothelioma survivor Kendra Ferreira took advantage of immunotherapy after she was diagnosed and has outlived her prognosis by a decade.
Of course, there is no guarantee that experimental treatments will have a definitive effect on a patient’s cancer. Yet, patients can find comfort in knowing that these treatments are on the cusp of becoming effective standards. Staying hopeful and giving clinical trials a shot can make all the difference.
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