Written By: Camryn Keeble
Keytruda for Mesothelioma
Keytruda is a type of mesothelioma immunotherapy approved for the treatment of pleural mesothelioma. It has been shown to improve overall survival compared with chemotherapy alone. Keytruda can improve survival and life expectancy for some patients.
Medically Reviewed By
Karen Ritter, RN BSN
Registered Nurse
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Important Facts About Keytruda for Mesothelioma
- The FDA approved Keytruda for the treatment of unresectable, malignant pleural mesothelioma in September 2024.
- Keytruda is the brand name of the checkpoint inhibitor immunotherapy drug pembrolizumab.
- Keytruda is now approved as one of the first-line treatment options when given in combination with chemotherapy.
- Since Keytruda stimulates the immune system, side effects can occur when the immune system attacks healthy tissues. These side effects can range from mild to more severe.
FDA Approval of Keytruda for Mesothelioma
The U.S. Food and Drug Administration (FDA) approved Keytruda in September 2024 as a first-line option to treat unresectable, malignant pleural mesothelioma. This type of mesothelioma forms in the lining of the lungs.
The FDA approval requires patients to use Keytruda in combination with chemotherapy. “Unresectable” means surgery is not an option to treat the cancer.
Keytruda is not yet approved for peritoneal mesothelioma (mesothelioma of the abdominal cavity lining).
How Keytruda Works for Mesothelioma
Keytruda is a type of mesothelioma immunotherapy called a checkpoint inhibitor. These types of immunotherapies boost the immune system’s ability to respond to cancer cells.
In more technical terms, Keytruda blocks PD-1 protein receptors on immune system T-cells. This prevents cancer cell proteins from attaching to the receptors and shutting down the immune response. As a result, the immune system can continue to recognize and attack cancer cells.
PD-1 and PD-L1
The immune system has soldier cells, called T-cells, that attack and kill diseases. However, mesothelioma cells have surface proteins that subdue or prevent the T-cells from doing their job.
Mesothelioma tumors have a protein called PD-L1, which can bind to the PD-1 protein receptor found on T-cells. When PD-L1 and PD-1 bind together, T-cells no longer recognize mesothelioma tumors as a threat to the body. This means they cannot actively fight off the disease, allowing cancer to spread freely.
Keytruda Blocks PD-L1
Keytruda blocks interactions between the PD-L1 proteins and PD-1 protein receptors, preventing them from binding. By blocking the interaction, T-cells remain active and alert, ready to fight off mesothelioma.
This therapy helps the immune system to attack, helping to kill mesothelioma cancer cells and preventing them from growing and spreading throughout the body.
Mesothelioma Survival and Keytruda
Mesothelioma survival after receiving Keytruda is promising. Keytruda in combination with chemotherapy performed better in terms of overall survival than chemotherapy alone.
A phase 3 clinical trial called KEYNOTE-483 included 440 people with unresectable, malignant pleural mesothelioma. Half of the patients received Keytruda with chemotherapy. The other half received only chemotherapy.
- Median survival for patients receiving Keytruda with chemotherapy was 17.3 months.
- Chemotherapy alone led to a median survival of 16 months.
- Approximately 52% of patients had a positive anti-tumor response from Keytruda and chemotherapy.
- Only 29% of patients had a positive anti-tumor response after only chemotherapy.
- Keytruda and chemotherapy stopped mesothelioma from spreading for at least a year in 26% of cases.
- Chemotherapy alone had a lower percentage.
Side Effects of Keytruda
Safety of a medication is often measured by the frequency and severity of side effects. Chemotherapy’s side effects range from mild fatigue to severe nausea. Chemotherapy for mesothelioma can also weaken bones, lower red and white blood counts, and cause neuropathies (nerve damage) in extremities.
Like many cancer treatments, Keytruda can cause side effects. Most are manageable but some can become more serious if not treated promptly. Common side effects for Keytruda include:
- Fatigue
- Muscle pain
- Rash/itching
- Diarrhea
- Fever
- Cough
- Decreased appetite
- Joint pain
- Shortness of breath
- Abdominal pain
- Nausea
- Low levels of thyroid hormone
More serious side effects are possible but less common. Keytruda can cause immune-related side effects that can affect the lungs, liver, kidneys, intestines and thyroid gland.
If you experience any new or worsening side effects, contact your doctor immediately. Early identification and treatment of side effects can minimize the risk of severe complications. Side effects may result in a change in your treatment options.
How Patients Receive Keytruda for Mesothelioma
When used to treat pleural mesothelioma, Keytruda is given as an intravenous (IV) infusion along with chemotherapy. Patients receive Keytruda, pemetrexed, and either cisplatin or carboplatin during their treatment regimen. The medications are typically scheduled for once every three weeks. The exact treatment schedule may vary depending on the patient’s specific treatment plan, overall health, response to treatment, and side effects.
Mesothelioma patients typically receive the chemotherapy portion for 4 to 6 cycles but may continue Keytruda for an extended length of time as a maintenance treatment. Some patients have received Keytruda every few weeks for multiple years. The length of treatment depends on how tumors respond to the immunotherapy and whether the patient experiences any severe side effects.
How to Get Keytruda for Mesothelioma
The first step to get Keytruda for mesothelioma is to receive a confirmed medical diagnosis. This involves an initial consultation with a doctor, imaging tests to look for evidence of cancer, and a tissue biopsy to get a detailed pathology report.
If your mesothelioma is in an early stage, you may be a candidate for surgery. For patients who are eligible, surgery is often associated with better long-term disease control. Keytruda is not currently FDA-approved for patients who can have surgery.
If you are diagnosed with pleural mesothelioma and surgery is not possible, then you may qualify for treatment with Keytruda plus chemotherapy.
Mesothelioma patients are encouraged to see a mesothelioma specialist to determine the best treatment plan for their specific type of cancer.
Mesothelioma Guide has free resources to help you learn more about Keytruda and other treatments for mesothelioma. Contact our registered nurse Karen Ritter at karen@mesotheliomaguide.com for personalized help.
Frequently Asked Questions About Keytruda for Mesothelioma
Is Keytruda approved for mesothelioma?
Yes, Keytruda is approved by the FDA as a first-line treatment option for unresectable, malignant pleural mesothelioma. “Unresectable” means surgery is not an option to treat the cancer. Keytruda is approved for use in combination with mesothelioma chemotherapy.
How does Keytruda work?
Keytruda is an immunotherapy drug that stimulates the immune system’s ability to respond to cancer and other diseases. It blocks a protein from the mesothelioma cancer cell from binding to a protein receptor on the immune system T-cell. This blockade helps the immune system target and kill mesothelioma cells more accurately.
What are the side effects of Keytruda?
Side effects of Keytruda may include fatigue, muscle pain, diarrhea, cough, rash, fever, decreased appetite, itching, shortness of breath, constipation, bone pain, joint pain, abdominal pain, nausea and low levels of thyroid hormone. Side effects are often manageable when treated promptly. If you experience any new or worsening side effects, contact your doctor immediately.
Sources & Author
- FDA approves pembrolizumab with chemotherapy for unresectable advanced or metastatic malignant pleural mesothelioma. U.S. Food and Drug Administration. Retrieved from: https://www.fda.gov/drugs/resources-information-approved-drugs/fda-approves-pembrolizumab-chemotherapy-unresectable-advanced-or-metastatic-malignant-pleural. Accessed: 06/15/2026.
- How Does Keytruda Work? Keytruda (pembrolizumab). Retrieved from: https://www.keytruda.com/how-does-keytruda-work/. Accessed: 06/15/2026.
AI Summary of Keytruda for Mesothelioma
Keytruda is a medication that has been approved by the U.S. Food and Drug Administration (FDA) to treat a specific form of mesothelioma called pleural mesothelioma, which develops in the lining of the lungs. It is a type of immunotherapy, meaning it helps the body's immune system better recognize and fight cancer cells. This treatment is typically used along with chemotherapy for patients whose cancer cannot be removed through surgery, known as unresectable mesothelioma. While Keytruda offers hope and may improve survival for some patients, it is not yet approved for all types of mesothelioma, such as those affecting the abdomen, called peritoneal mesothelioma.
Keytruda works by blocking proteins on cancer cells that hide them from the immune system. Specifically, it targets a protein called PD-L1 on mesothelioma cells, preventing it from attaching to a protein called PD-1 on immune cells. When these proteins bind, immune cells, known as T cells, often fail to recognize the cancer as a threat. By blocking this interaction, Keytruda helps T cells remain active and better able to attack mesothelioma tumors. This enhancement of the immune response can slow the spread of the disease and, in some cases, shrink tumors. Treatment involves receiving the medication through an intravenous (IV) infusion every three weeks, and the duration of treatment varies based on individual responses and side effects.
Clinical studies have shown promising results, with some patients experiencing extended survival times and tumor control after treatment with Keytruda combined with chemotherapy. The median survival time for patients on this combined therapy was approximately 17 months, slightly longer than those receiving chemotherapy alone. Additionally, many patients responded positively, with a better ability for their immune system to target the cancer. While side effects are generally mild, some patients may experience fatigue, rash, muscle pain, digestive issues, or other symptoms. It is important for individuals receiving this treatment to be closely monitored by their healthcare team, who can manage any side effects that occur. Overall, Keytruda offers an important option for those with advanced pleural mesothelioma when surgery is not feasible, providing hope for a better quality of life and potentially lengthening survival."