Immunotherapy for Mesothelioma
Immunotherapy has shown promising results as a treatment option for patients with mesothelioma. Rather than using external methods like surgery, chemotherapy, and radiation, immunotherapy medications help the body’s immune system fight cancer on its own.
In October 2020, the U.S. Food and Drug Administration (FDA) approved two chemotherapy drugs as a treatment for pleural mesothelioma: nivolumab (brand name Opdivo®) and ipilimumab (brand name Yervoy®).
Scientists continue to study other immunotherapy drugs in clinical trials.
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.
Before the approval of Opdivo® and Yervoy®, immunotherapy was usually administered via clinical trial because the treatment was 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 the combination of Opdivo® and Yervoy® or 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.
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 its 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 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 other 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 also has the potential to increase life expectancy more than other mesothelioma treatments.
The FDA noted that pleural mesothelioma patients who received nivolumab and ipilimumab lived for 18 months on average, compared to 14 months for those treated with chemotherapy.
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 with the FDA approval of Opdivo® and Yervoy®.
In addition, some of the other immunotherapy drugs being tested in mesothelioma patients in clinical trials 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 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 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.
Nivolumab – also known by its brand name Opdivo® — allows the body’s T-cells, which destroy cancer cells, to recognize cancer more effectively. This is done by blocking a protein called PD-L1 in mesothelioma cancer cells.
PD-1 and PD-L1 are proteins that allow T-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.
Other anti-PD-L1 drugs, such as pembrolizumab (brand name Keytruda®) and durvalumab, also block PD-L1. These immunotherapy drugs are known as checkpoint inhibitors, as they prevent cancer cells from escaping detection.
Pembrolizumab has been approved by the FDA for the treatment of metastatic non-small cell lung cancer in combination with chemotherapy.
Ipilimumab (more commonly known by its brand name Yervoy®) complements anti-PD-L1 drugs by activating T-cells in the body, meaning that more mesothelioma cells will die.
Typically, only a certain number of T-cells are active in the body. This is done so that your body does not attack healthy cells by accident. T-cells are inactivated when immune-regulating cells administer a protein called CTLA-4.
Ipilimumab prevents CTLA-4 from reaching T-cells, allowing more to stay active.
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 a great way to receive immunotherapy treatment because many treatments (other than Opdivo® and Yervoy®) are 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 Opdivo®, Yervoy®, and 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, 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 immunotherapy and determine whether it is a good fit for you or your loved one with mesothelioma.