Keytruda®, Lung Cancer, and Mesothelioma

Merck's Keytruda shows promise for mesothelioma

Keytruda® (also known as pembrolizumab) is a new cancer-fighting drug that is making a big splash. Introduced by the pharmaceutical company Merck, Keytruda® belongs to a class of drugs known as monoclonal antibodies. Unlike traditional chemotherapy drugs Monoclonal antibodies are specialized proteins that are part of the body’s own immune system.

So how does it work? Researchers have known for awhile that some cancers contain a specific protein called PD-L1 that helps to protect them from attack. Keytruda® blocks this protein, allowing the immune system to attack and destroy the cancer cells.

Keytruda® Shows Promise in Clinical Studies

In the summer of 2014, Merck launched a new study called KEYNOTE-024 whose goal was to see if Keytruda® could do a better job of fighting cancer cells than some of the more traditional medications that are currently used. The study followed 305 patients with metastatic non-small cell lung cancer (NSCLC) who were previously untreated and whose tumors expressed high levels of the PD-L1 protein. Some of the patients received the standard chemotherapy treatment, which was usually a combination of carboplatin, cisplatin, pacilatexel and pemetrexed, while the rest were given Keytruda®.

About 11 months later, researchers followed up with all the patients and discovered the following results:

  • Keytruda® reduced the risk of cancer progression or death by 50% compared to the standard chemotherapy treatment.
  • The median (progression-free) survival for Keytruda® was 10.3 months compared to 6 months with standard chemotherapy.
  • Even at six months into the trial, 62.1% of patients treated with Keytruda® were alive and had no disease progression compared to 50.3% of those receiving standard chemotherapy.

By all measures, the results of this study were extremely impressive. Stefan Zimmermann of Lausanne’s University Hospital told reporters at a conference where the results were presented, “Remember this day. It’s a new day for lung cancer treatment.”

What Keytruda® Means for Mesothelioma Research

Lung cancer is the biggest cause of cancer deaths globally, so it’s a logical starting point for many researchers to begin with when trying new drugs for cancer treatment . But the work doesn’t stop there. With the success of Keytruda® in this trial, it is expected that research will expand to include its use in other types of cancer like mesothelioma.

In fact, clinical trials involving the use of Keytruda® in patients with Mesothelioma are already underway. One trial in particular, called KEYNOTE-028, is looking at patients with malignant pleural mesothelioma – a cancer of the lining of the lungs that is caused by exposure to asbestos – to see if these patients have better outcomes with Keytruda® than with standard treatments alone.

Keytruda® is especially important because it is a drug that mesothelioma patients who have exhausted all other treatment could potentially turn to as a last resort. Although the trial is still in its beginning phase, early results are promising.

Dr. Roger M. Perlmutter, the president of Merck Research Laboratories said of the initial Keytruda® trial, “These studies may represent a turning point in worldwide efforts to control lung cancer.” Only time will tell if these words prove to be prophetic, and it is hoped that with the Food and Drug Administration’s recent approval of Keytruda® for the treatment of metastatic NSCLC that the same may soon happen for mesothelioma.