Initial results from a clinical trial led by Merck and the Canadian Cancer Trials Group (CCTG) show that the immunotherapy drug Keytruda® (pembrolizumab) improved overall survival for pleural mesothelioma patients when combined with chemotherapy.

The KEYNOTE-483 trial included 440 patients with late-stage pleural mesothelioma who were not eligible for surgery.

Patients who received the immunotherapy drug pembrolizumab alongside chemotherapy had higher overall survival rates. The combination of treatments appears to be more effective than chemotherapy alone.

Mesothelioma is an incredibly aggressive cancer with an average prognosis of 12-16 months in its later stages. However, new and emerging treatment options are helping patients live longer.

The preliminary findings from the KEYNOTE-483 study provide more supporting evidence of the benefits of immunotherapy as part of a multimodal treatment plan — and good news for those battling late-stage pleural mesothelioma.

“There have been few treatment advances for patients with malignant pleural mesothelioma, which can be challenging to treat through surgery and radiation alone,” said Dr. Quincy Chu, chair of the study. “The results from the trial have the potential to make a difference for patients with this disease who have had limited treatment options available to them.

Merck and the CCTG will release detailed survival rates from the trial after presenting the full results at an upcoming medical meeting.

Keytruda® Could Join Other Immunotherapy Drugs as an Effective Mesothelioma Treatment Option

Since the U.S. Food and Drug Administration (FDA) approved Opdivo® (nivolumab) and Yervoy® (ipilimumab) for unresectable (not treatable through surgery) pleural mesothelioma in October 2020, immunotherapy has shown growing promise as an effective treatment for mesothelioma.

Did You Know?

When a specific protein found on immune cells known as PD-1 binds with another protein called PD-L1, it makes it easier for cancer cells to sneak past the immune system without triggering a response. Keytruda works by blocking PD-L1, which increases the immune system’s ability to identify and kill cancer cells.

Based on the outcomes of the KEYNOTE-483 study and other mesothelioma clinical trials, immunotherapy drugs may eventually become a standard treatment for mesothelioma.

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Get Help Accessing Immunotherapy Treatment for Mesothelioma

Not every mesothelioma patient is a suitable candidate for immunotherapy. Factors such as your age, overall health, and cancer stage all affect your eligibility for treatments.

Additionally, since immunotherapy drugs affect the body’s ability to identify all types of cells, it is possible for the immune system to attack healthy cells. Some patients may experience what doctors call “toxicity” to various immunotherapy treatments, which can cause adverse reactions.

For this reason, it is important to speak with a specialist about the potential risks and benefits of available treatment options. Use our free Mesothelioma Doctor Match today to get help connecting with specialists near you.

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Laura WrightWritten by:

Lead Editor

Laura Wright is a journalist and content strategist with more than 15 years of professional experience. She attended college at the University of Florida, graduating magna cum laude with a bachelor’s degree in journalism in 2008. Her writing has been featured in The Gainesville Sun and other regional publications throughout Florida.

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  1. Banks, K. C., Ossowski, S., Hung, Y., et al. (2022). “Comparison of Survival by Multimodal Treatment Regimen Among Malignant Pleural Mesothelioma Patients in an Integrated Health System.” Clinical Lung Cancer, 23(8), 694-701. Retrieved April 14, 2023, from

  2. Merck and Canadian Cancer Trials Group. (2023). “KEYTRUDA® (pembrolizumab) Plus Chemotherapy Significantly Improved Overall Survival Versus Chemotherapy Alone as First-Line Treatment for Advanced Malignant Pleural Mesothelioma.” Retrieved April 14, 2023, from

  3. Mesothelioma Applied Research Foundation. (2023). “Immunotherapy for Mesothelioma: What’s Next?” Retrieved, April 14, 2023, from

  4. National Cancer Institute. (n.d.). PD-1. Retrieved April 13, 2023, from

  5. Shah, R., Klotz, L. V., & Glade, J. (2022). “Current Management and Future Perspective in Pleural Mesothelioma.” Cancers. Retrieved April 14, 2023, from

  6. U.S. Food & Drug Administration. (2020). FDA Approves Drug Combination for Treating Mesothelioma. Retrieved April 14, 2023, from

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