Clinical trials involving immunotherapy are standard in the mesothelioma treatment world.
Another one just finished the first phase of testing — and showed hope for pleural mesothelioma patients.
The trial involves immunotherapy and chemotherapy, a combination often called chemoimmunotherapy. According to an article posted on the Clinical Cancer Research website, the opening phase concluded with an 89 percent disease control rate, which is excellent news for patients.
The trial tested CRS-207, which induces anti-tumor immune responses to prevent mesothelioma’s growth in the body and attack the cancerous cells. First, let’s explain how CRS-207 fends off mesothelioma tumors.
How CRS-207 Works
Pleural mesothelioma is the most common of the three types of mesothelioma, which forms in the protective membrane lining specific areas of the human body. This membrane includes mesothelial cells and surrounds the lungs, abdomen and heart. When asbestos fibers are inhaled or ingested, they can enter these three pathways and aggravate cells, which then turn into tumors.
Mesothelin is a protein expressed in these mesothelial cells, and high levels of this protein is one sign of mesothelioma’s presence since the mesothelial cells mutate, grow and duplicate throughout the body.
CRS-207 is, according to the Clinical Cancer Research website, a live-attenuated Listeria monocytogenes. A bacterium, it enters the body and triggers the immune system to react to its presence. Cancer is dangerous because the disease suppresses the immune system, an act which allows the tumors to metastasize without any resistance.
The theory of immunotherapy is if a bacterium or other virus enters the body, then the immune system could activate its defenses and fend off all unwanted inhabitants inside the body. For many of this clinical trial’s participants, the CRS-207 infusions did just that.
Results of the Immunotherapy Trial
Participants in the study received not only CRS-207 but also the chemotherapy combination of pemetrexed and cisplatin, which is the principal pairing for mesothelioma patients. Chemoimmunotherapy for mesothelioma is a rising trend among clinical trials.
Patients received two priming infusions of CRS-207, followed by the chemotherapy drugs and a CRS-207 booster infusion. Of the 35 participants, 31 (89 percent) had disease control, meaning their mesothelioma didn’t worsen. If mesothelioma exists in a person’s body but never metastasizes to any vital organs, then the person can live with the cancer for the rest of their life. This phenomenon is called “dormant mesothelioma.”
One of the 31 people had a complete response, meaning their mesothelioma decreased significantly in size. Ten of the participants had a stable disease, meaning their cancer neither grew nor reduced in size. Nineteen others experienced a partial response, meaning their mesothelioma decreased in size. These results were included in the Clinical Cancer Research page about the study.
The scientists concluded the Clinical Cancer Research article by saying the combination of immunotherapy and the chemotherapy drugs “induced significant changes in the local tumor microenvironment and objective tumor responses” in most of the participants. In other words, this phase of the trial was a success.
There are numerous ongoing clinical trials, and new ones surface regularly. Mesothelioma patients may receive new and promising treatment options to manage or even kill their cancer. Our patient advocate, Jenna Campagna, has connections throughout the medical community and can help you sign up for a clinical trial that fits your diagnosis. Contact her at firstname.lastname@example.org to learn about the next immunotherapy trials for mesothelioma.
Show Sources & Author
- Live-Attenuated, Listeria monocytogenes Expressing Mesothelin (CRS-207) with Chemotherapy for Treatment of Malignant Pleural Mesothelioma. Clinical Cancer Research. Retrieved from: https://www.cancer.gov/publications/dictionaries/cancer-drug/def/live-attenuated-listeria-monocytogenes-cancer-vaccine-adxs11-001. Accessed: 07/12/19.