Keytruda for Mesothelioma and Lung Cancer

Keytruda is a brand name for the drug pembrolizumab, developed, manufactured, and sold by Merck to treat certain types of cancer. It was first approved by the U.S. Food and Drug Administration (FDA) in 2014 to treat metastatic melanoma and other types of cancer, including non-small cell lung cancer in patients with certain genetic features, called biomarkers. This is the first time has approved a cancer drug based on genetics.

What is exciting about Keytruda for people affected by asbestos is that early studies are showing it may prove a useful chemotherapy drug for mesothelioma. More research is needed but the results are promising and could lead to a new therapy for mesothelioma patients who have few other options for effective treatment.

Pembrolizumab and Immunotherapy

Keytruda is an immunotherapy drug designed to help the immune system of the body attack and kill cancer cells. Immunotherapy is a newer line of treatment for cancer that harnesses the natural power of the immune system. The immune system works when cells, like white blood cells, recognize and attack foreign invaders in the body, like viruses. They recognize these pathogens because of receptors called antigens on their surfaces. Healthy, normal cells in the body have receptors on their surfaces that signal to immune cells that they are healthy and not to be attacked.

Some types of cancer cells express these receptors, called PD-1 proteins. These allow the cancer cells to appear like healthy cells to the immune system, so they do not get attacked and continue to grow and thrive. Pembrolizumab acts on those receptors on the cancer cells, blocking their message and allowing the immune system to recognize them as foreign and to attack and destroy them. The strategy is referred to as immune checkpoint blockade.

Indications and Side Effects

The FDA approved Keytruda for specific types of cancers, for cancers in certain stages or with certain characteristics, and for cancers in patients with certain biomarkers. For instance, it is approved for melanoma, but only melanoma that has spread throughout the body and cannot be treated surgically. For other cancers, like non-small cell lung cancer, it is approved only in cases in which the patient’s cancer worsened after attempting to treat it with standard chemotherapy drugs.

Side effects with pembrolizumab can be serious, but the most common are fatigue, rash, diarrhea or constipation, nausea, decreased appetite, shortness of breath, coughing, and itching. More serious, but less commonly, patients may experience bruising, anemia, numbness, dizziness, hot flushes, flu-like symptoms, hair loss, edema, irregular heartbeat, pain, kidney failure, infections, insomnia, diabetes and jaundice. Chest pains, shortness of breath, and a cough may indicate a serious reaction that should be addressed immediately.

Keytruda for Mesothelioma

Right now the indications for Keytruda do not include treating mesothelioma, but studies are underway to determine if it could be an effective and safe treatment for this cancer. Most recently, a study was published in The Lancet Oncology, and showed promising results. The study has shown that while other chemotherapy drugs are failing to treat this difficult type of cancer, immune checkpoint drugs may be a better alternative.

The clinical trial is called KEYNOTE-028 and it involves 13 research teams in six different countries. The trial includes patients with various types of advanced cancer, including 25 patients with pleural mesothelioma. All of these patients had either received unsuccessful chemotherapy treatment prior to the trial or were not eligible for chemotherapy.

The 25 mesothelioma patients received an injection of pembrolizumab every two weeks and the results were that 14 of the patients saw reductions in tumor size. They experienced an average of six months of reduction or lack of progression of the cancer. The average survival time was 18 months. Four patients are still alive and undergoing treatment with pembrolizumab, two years later.

While 18 months survival may not sound that encouraging, it is a major improvement. Most patients with pleural mesothelioma that receive some type of second-line treatment will only survive an additional six months. With four patients surviving past the two-year mark, the treatment with Keytruda shows great promise over other options for mesothelioma patients. While there were common side effects in the participants, like fatigue and nausea, none had to stop because of the severity of these side effects.

Keytruda for Asbestos Lung Cancer

Pembrolizumab is now showing promise for mesothelioma patients, but it is already approved for treating non-small cell lung cancer, another type of cancer that can be triggered by asbestos exposure. Approval for treating this kind of cancer came after results from clinical trials showed it to be safe and effective. More recent studies have shown that it may actually be better than standard chemotherapy drugs like cisplatin and carboplatin.

The study examined the results of the KEYNOTE-024 clinical trial of pembrolizumab in non-small cell lung cancer patients. The data showed that this drug had several advantages over traditional chemotherapy. Patients given pembrolizumab saw better overall survival rates, fewer side effects, less severe side effects, and better quality of life. Some side effects were worse with pembrolizumab, but overall adverse effects were lower and less severe. The benefits of pembrolizumab were seen in using it as a first-line treatment. This could mean that patients with lung cancer may be able to use the drug instead of cisplatin or carboplatin and avoid the adverse effects, getting better results sooner.

The promise of immunotherapy drugs for treating cancer is overwhelmingly positive, and Keytruda in particular is leading the way in finding a new strategy for better treating mesothelioma in victims of asbestos exposure. Researchers are getting on board and there are now more than 90 clinical trials ongoing using Keytruda to treat various types of cancers.

Two new mesothelioma trials are expected to start later this year. If you are struggling with mesothelioma, pembrolizumab is not currently approved for treatment, but you may be able to participate in a clinical trial. Talk to your doctor about how you can get involved if you qualify because this could prove to be a revolutionary and life-saving, or at least life-extending treatment for this difficult type of cancer.