Tremelimumab
Earlier in the spring of 2017, scientists and researchers from the University of Salford in the UK published a special report questioning the effectiveness of the new immunotherapy treatment known as tremelimumab. Trials of the check point inhibitor did not show promising results and there was concern about the drug’s effectiveness, safety, and tolerability.
Tremelimumab binds to the protein called CTLA-4 and is designed to help the immune system locate and attack the cancerous cells by interfering with the way cancerous cells conceal themselves. In this double-blind, placebo-controlled, Phase 2b trial, 571 patients were recruited across 19 countries in December 2014. These patients all had unresectable mesothelioma, both pleural and peritoneal. Patients were randomly assigned to either receive the placebo or tremelimumab, once a month for 7 months, and then once every 3 months after that. All the patients had received chemotherapy previously without much success.
Results showed that 80% of those who were part of the tremelimumab group and 81% of the placebo group had died, indicating that the median overall survival did not really differ between the two groups.
The future of tremelimumb is questionable and won’t be considered for second or even third-line treatment, but research is on-going to see if it can be used as combination therapy treatment.
High-dose Palliative Radiation Treatment
Radiation treatment for mesothelioma is not the most effective, but headway has been made with the use of Intensity Modulated Radiation Therapy (IMRT) and Radio-immunotherapy. However, when it comes to palliative therapy, high-doses of radiation were found to take a toll on the already fragile state of a mesothelioma patient’s health.
After 2 years of chemotherapy, seventy-one patients with pleural mesothelioma were irradiated with 45-60Gy. Split into two groups, seventeen had conformal radiotherapy to the lower hemithroax, or half of the chest, and 54 patients experienced IMRT to the entire chest area. Unfortunately, results were disappointing. While 90% of patients were able to complete the treatment, progression-free survival was only 4.9 months and severe toxicity to the radiation treatment occurred in over half of the patients. Eighty-seven percent of patients died or had disease progression within 2 years of the treatment. The study concluded that high-doses of radiotherapy did not improve survival and was toxic to most patients.
Mesothelioma continues to be an aggressive cancer that is difficult to treat. At times, negative study results can be discouraging, but doctors, scientists, and researchers use all test results, good and bad, to further study and analyze parts of the treatments that do work, in hopes to create a treatment that is most effective.
Sources:
Foroudi F, et.al. “High-dose Palliative Radiotherapy for Malignant Pleural Mesothelioma,” Journal of Medical Imaging and Radiation Oncology (June 20, 2017). [Link]
Majo, M, et. al. “Tremelimumab As Second-Line Or Third-Line Treatment In Relapsed Malignant Mesothelioma (Determine): A Multicentre, International, Randomised, Double-Blind, Placebo-Controlled Phase 2b Trial,” The Lancet Oncology (July 17, 2017). [Link]
