What Is Keytruda?
Pembrolizumab, under the brand name Keytruda, was first invented by scientists Gregory Carven, Hans van Eenennaam, and John Dulos. While the FDA hasn’t approved Keytruda for mesothelioma treatment, the medication has been approved to treat melanoma, head and neck cancer, metastatic bladder cancer, metastatic non-small cell lung cancer, and colorectal cancer. Researchers are currently testing Keytruda on mesothelioma patients in clinical trials.
In September of 2014, the FDA approved pembrolizumab under the Fast Track Development Program, which accelerates the availability of a new or non-approved drug. Doctors administer pembrolizumab as a first or second-line treatment by aiding the body’s immune system to fight cancer cells.
How Keytruda Works
Immunotherapy drugs like Keytruda help the immune system, which is the body’s natural defense against disease. The body uses T-cells, sent by the immune system, to detect and fight cancer cells. Cancer cells may hide from T-cells using the PD-1 pathway, a type of protein found in the body’s immune cells.
Antibodies are proteins produced by plasma cells and used by the immune system to eliminate viruses, bacteria, and cancer cells. The pembrolizumab binds to and blocks PD-1, so the T-cells can continue to eliminate cancer cells.
Malignant mesothelioma tumors consist of cells that often contain high levels of PD-L1, Researchers use Keytruda to block the PD-1 and PD-L1 pathway, which would allow the patient’s immune system to recognize and attack mesothelioma cells.
Patients receive Keytruda via intravenous therapy (IV) for 30-minute increments every three weeks. Cancer patients who tolerate Keytruda will typically continue treatment for up to two years, or until the dug continues to be effective.
Pembrolizumab Side Effects
Patients who receive pembrolizumab may experience mild-to-severe side effects. Side effects can occur at the site of infusion or immune-related in response to treatment. Common reactions can include:
- Decreased appetite
- Dry skin
- High blood pressure
- Joint Pain
- Mouth sores
- Shortness of breath
In rare situations, Keytruda may cause the immune system to attack normal organs and tissues, affecting their ability to function properly. Serious reactions typically affect the lungs, intestinal tract, kidneys, liver, and some hormone glands.
Less-common side effects may include:
- Abdominal pain
- Chest pain (myocarditis)
- Colon inflammation
- Decreased appetite
- Diabetic ketoacidosis
- Distortion of the sense of taste
- Dry eye
- Dry mouth
- Eye pain (sarcoidosis)
- Inflammation of the pituitary gland
- Kidney failure
- Kidney inflammation
- Liver inflammation
- Lung inflammation
- Muscle pain
- Myasthenia gravis
- Pain in a limb
- Severe skin reactions
Cancer patients taking Keytruda can receive medications or therapies to eliminate side effects or keep them under control.
Keytruda In Clinical Trials
Pembrolizumab has been tested in clinical trials on multiple types of cancer. Some trials have shown success in treating certain cancers, but trails testing the drug on mesothelioma patients haven’t shown as much success.
Early trials testing Keytruda on advanced or unresectable melanoma in 2014 lead to the drug’s approval by the FDA as a second-line treatment. Some study participants experienced increased survival, tumor reduction, and reduced risk of disease progression.
In 2015, Keyturda was approved as a first-line treatment of melanoma after a successful phase 3 trial. The drug was previously approved by the European Commission earlier that year. Keytruda as a first-line treatment for non-small cell lung cancer was approved by the FDA in 2016, and for metastatic non-squamous non-small cell lung cancer in 2017.
Researchers at the European Thoracic Oncology Platform (ETOP) completed a phase 3 trial on pembrolizumab for mesothelioma treatment in 2019. The randomized trial, called PROMISE-meso, compared pembrolizumab with standard chemotherapy in patients with progressive malignant pleural mesothelioma.
Researchers hoped that the drug would improve the performance of single-agent immunotherapy as a second-line treatment for patients who successfully completed first-line, standard chemotherapy treatment.
The leading study author, Sanjay Popat, Ph.D., demonstrated in a presentation that the drug had failed to change disease outcomes on study subjects. Although results weren’t successful, the study provided researchers with new hope for combining immunotherapy with chemotherapy as a beneficial first-line treatment for malignant mesothelioma.
While treatment options like chemotherapy, radiation, and surgery continue to be the standard treatment, researchers believe immunotherapy shows promise in treating mesothelioma. Multiple clinical trials testing immunotherapy drugs like Keytruda. To learn more about treating mesothelioma, download our free mesothelioma guide.