What Is Immunotherapy?
Immunotherapy is an experimental treatment for mesothelioma. Many different types of drugs are being studied, but they all work by improving immune system function.
Results from clinical trials suggest that immune checkpoint inhibitors such as pembrolizumab (Keytruda), nivolumab (Opdivo) and ipilimumab (Yervoy) show the most promising results in pleural patients.
Immunotherapy does not offer a cure for mesothelioma, but it combines well with other therapies to manage pleural mesothelioma better as a chronic disease.
Types of Immunotherapy
The types of immunotherapy recently studied for pleural mesothelioma include cancer vaccines, immune checkpoint inhibitors, monoclonal antibodies and adoptive cell transfer.
Other types of immunotherapies studied on pleural patients in the past include cytokines — such as interleukin-2 — and Bacillus Calmette-Guerin, a bacterial immunotherapy.
Cancer vaccines help the immune system locate and kill cancer cells. Several vaccines are in development to prevent and treat pleural mesothelioma.
- A preventative vaccine called HIvax is under development at the University of Hawaii. It remains in the animal testing phase.
- A therapeutic stem cell vaccine called iPSC also remains in the animal testing phase at Stanford University School of Medicine.
- A phase II trial of a therapeutic vaccine called WT1 reported an overall survival of 22.8 months among pleural patients receiving the vaccine, while placebo patients survived 18.3 months. A phase III trial is waiting on funding.
Immune Checkpoint Inhibitors
Immune checkpoint inhibitors help the immune system identify and attack cancerous cells.
Several inhibitors are in development for pleural mesothelioma:
- Imfinzi (durvalumab)
Mesothelioma clinical trials are combining these drugs with each other and with chemotherapy drugs. While no immune checkpoint inhibitor has been proven to cure pleural mesothelioma, they have helped many patients live longer with the cancer.
Monoclonal antibody therapy activates cancer-killing pathways in the immune system. A few monoclonal antibodies have been tested on pleural mesothelioma patients.
- Tremelimumab is an immune checkpoint inhibitor and a monoclonal antibody. Clinical trials are combining it with other inhibitors and chemotherapy drugs. Preliminary results suggest the drug works for some pleural patients, but not all.
- Amatuximab made it to a phase II clinical trial in pleural mesothelioma patients. One patient responded well for years on the drug, but others only survived for 14.8 months.
Adoptive Cell Transfer
Adoptive cell transfer uses live immune cells to boost the immune system. A patient’s immune cells are extracted from a blood sample and multiplied or modified in a lab. Then the cells are transferred back into the patient, this time in much higher quantity to give the immune system a natural boost.
- CAR T-cell therapy is in the early phases of being tested on pleural mesothelioma patients. These trials are investigating how to safely apply the therapy in pleural patients.
- Dendritic cell therapy has been studied in pleural patients with mixed results. Most of these studies are taking place in Europe and Asia. The only dendritic cell therapy trial in the U.S. for mesothelioma is for the peritoneal type and is not open to pleural patients.
Side Effects of Immunotherapy
The side effects of immunotherapy on pleural mesothelioma patients include:
- Skin reactions near needle site
- Skin rash or blisters
- Nausea or vomiting
- Loss of appetite
- Shortness of breath
- High or low blood pressure
- Inflammation of the digestive tract
- Vision loss or retinal detachment
Patients who experience shortness of breath, yellowing of skin, blood in stool or urine, severe headache or vision problems should consult their mesothelioma doctor immediately.
Future of Immunotherapy for Mesothelioma
Immunotherapy will soon become part of standard care for mesothelioma rather than an experimental therapy. The extensive research underway now will eventually lead to effective immunotherapies approved by the U.S. Food and Drug Administration.
Immune checkpoint inhibitors are currently producing the best survival rates among pleural patients. Other types of immunotherapy are showing promise as well, especially when combined with other therapies.
Pleural patients with specific qualifications can access these therapies with the help of their oncologist.
The future of mesothelioma treatment will involve immunotherapy and likely several different types to control mesothelioma in diverse ways.