Immunotherapy for Mesothelioma
Immunotherapy has shown promising results as an emerging treatment option for patients with the terminal cancer.
Mesothelioma begins in the lining of the lungs and quickly spreads to the rest of the chest cavity and other vital organs. It generally affects individuals who have had prolonged exposure to asbestos. Asbestos fibers that get stuck in the lungs can lead to cancer 30 to 40 years after the initial exposure.
Researchers are constantly looking for new treatments that can extend the life span of mesothelioma patients. Immunotherapy could eventually become a more mainstream treatment for mesothelioma.
What is Immunotherapy?
Immunotherapy uses the body’s natural immune system to identify and destroy cancer cells. It differs from chemotherapy in that immunotherapy is a more targeted treatment which only kills abnormal cells, while chemotherapy also kills cells that are healthy. Immunotherapy side effects are also milder than side effects of other aggressive treatments.
Immunotherapy is usually administered via clinical trial because the treatment is still experimental. This means that while many patients see an improvement in their symptoms, some patient conditions may not improve.
Mesothelioma patients interested in immunotherapy should check with their doctor to determine if they are a good fit for clinical trials.
Types of Immunotherapy
There are several different types of immunotherapies, each with their own particular focus. The most common immunotherapies are listed below.
Cancer Vaccines
Researchers are currently working on preventative mesothelioma vaccines. CRS-207 is a listeria-based cancer vaccine that has had some success in clinical trials.
A Norwegian biotech firm, Targovax, has also had early signs of success in their ONCOS-102 trial testing mesothelioma vaccines in combination with standard chemotherapy in several patients.
Immune Checkpoint Inhibitors
Immune checkpoint inhibitors prevent cancer cells from hiding from the body’s immune system. This is done by targeting certain proteins on cancer cells called “checkpoints.” The checkpoints targeted by mesothelioma immunotherapies include CTLA-4, PD-L1 and PD-1.
Monoclonal Antibodies
Monoclonal antibodies focus on a particular site inside of a cancer cell, such as a protein or enzyme. Sometimes antigens on the surface of a cell are also targeted. Monoclonal antibodies used to treat mesothelioma include Tremelimumab and Amatuximab.
Benefits of Immunotherapy
One of the strongest benefits of immunotherapy is its targeted approach with fewer side effects than more traditional treatments.
Chemotherapy often leaves patients feeling weak and disoriented because the medicine used kills cancer cells and healthy cells alike. However, immunotherapy can target only abnormal cancer cells, leaving healthy cells alone.
When immunotherapy is successful, it can provide patients with a feeling of relief. Immunotherapy has the potential to increase life expectancy more than other mesothelioma treatments.
However, it is important to remember that immunotherapy remains experimental and none of these methods have a guarantee of success.
Can Immunotherapy Help Mesothelioma Patients?
Immunotherapy remains an experimental treatment, so there is no telling how effective it may be on any particular patient.
Patients should remember that immunotherapy is not a cure and most doctors view it as a form of management therapy for mesothelioma. However, doctors are optimistic that immunotherapy will become more readily available to the general public in the near future.
Many of the immunotherapy drugs being tested in mesothelioma patients have already received FDA approval for the treatment of other cancers.
Immunotherapy Drugs Used for Mesothelioma
The most common immunotherapy drugs used to treat mesothelioma include:
CRS-207
CRS-207 is a listeria-based cancer vaccine that has had encouraging results in treating mesothelioma in the past. However, Aduro Biotech, the company behind the treatment, has recently canceled the CRS-207 program because of concerns about listeria infections.
Tremelimumab
Tremelimumab is an AstraZeneca immunotherapy developed to identify and target cancer cells. It is classified as a monoclonal antibody treatment. The immunotherapy has yet to receive any FDA approval.
Anti-PD-1/Anti-PD-L1
PD-1 and PD-L1 are proteins which allow white blood cells to communicate with healthy cells in the body.
High levels of PD-L1 indicate that a cell is healthy and should be left alone by the immune system. Cancer cells use high PD-L1 levels to mask their cancer status and avoid detection.
Anti-PD-L1 drugs, also known as checkpoint inhibitors such as pembrolizumab, nivolumab and durvalumab block PD-L1 in mesothelioma cancer cells, allowing the immune system to recognize and attack mesothelioma.
Pembrolizumab, or Keytruda, has been approved by the FDA for treatment of metastatic non-small cell lung cancer in combination with chemotherapy.
Clinical Trials for Immunotherapy
Clinical trials allow for research into experimental treatments in a controlled environment. They are run by medical research teams and doctors who are regulated by the FDA.
Clinical trials are currently the best way to receive immunotherapy treatment because the medicine is not yet available to the general public. Each clinical trial has its own eligibility criteria, so it is important to talk with your doctor to determine your eligibility.
The research data gleaned from clinical trials helps doctors to establish better treatments for the future.
Is Immunotherapy an Option For You?
If you or a loved with mesothelioma are interested in immunotherapy, talk to your physician about the availability of clinical trials. The U.S. National Library of Medicine also offers a public government database of clinical trials for prospective patients to look through.
Immunotherapy may be able to reduce the spread of cancer and increase life expectancy in some patients. However, these methods remain experimental. There may be a risk of side effects, and treatments may not work as intended and fail to limit the growth and spread of cancer throughout the body.
Your doctor can help assess if you are eligible for a clinical trial and determine whether it is a good fit for you or your loved one with mesothelioma.
