Keytruda
Keytruda (pembrolizumab) is an immunotherapy medication that’s used to treat many different types of cancer, including non-small cell lung cancer (NSCLC), breast cancer, and melanoma. This medication turns on your immune system so it can attack cancer cells. It's given as an intravenous (IV) infusion at a medical office or infusion center. Sometimes, Keytruda (pembrolizumab) can cause side effects, like diarrhea, rash, and trouble breathing, that might need to be treated with corticosteroids. Depending on the cancer, your treatment plan can consist of Keytruda (pembrolizumab) by itself or with other anticancer therapy.
What is Keytruda (pembrolizumab)?
What is Keytruda (pembrolizumab) used for?
Certain types of:
Non-small cell lung cancer (NSCLC)
Renal cell carcinoma (kidney cancer)
Endometrial carcinoma (uterine cancer)
Cancers with high tumor mutation burden (TMB-H), high microsatellite instability (MSI-H), or deficient mismatch repair (dMMR)
How Keytruda (pembrolizumab) works
Your immune system helps protect you from harm in many ways. For example, it can attack and kill cancer cells that it recognizes as abnormal. But some cancer cells can hide from your immune system using a process called the programmed death-1 (PD-1) pathway. When this happens, your immune system can’t find and attack the cancer cells as well, so the cancer can grow.
Keytruda (pembrolizumab) is an immunotherapy medication that blocks the PD-1 pathway. It’s also called a PD-1 inhibitor or checkpoint inhibitor.
By blocking the PD-1 pathway, Keytruda (pembrolizumab) helps the immune system find and recognize cancer cells again. As a result, the immune system can attack and kill the cancer cells and stop the cancer from growing.
Drug Facts
More on Keytruda (pembrolizumab) essentials
What are the side effects of Keytruda (pembrolizumab)?
Common Side Effects
- Higher blood sugar (52%)
- Anemia (43%)
- Higher liver enzyme levels (up to 33%)
- Electrolyte changes in blood (up to 31%)
- Lower white blood cells (30%)
- Tiredness (25%)
- Lower appetite (17%)
- Trouble breathing (17%)
- Cough (16%)
- Rash (15%)
- Diarrhea (12%)
- Constipation (12%)
- Nausea (12%)
Other Side Effects
- Pneumonia
- Weight loss
- Fever
- Hypothyroidism (low thyroid hormone levels)
Serious Side Effects
- Serious immune-related side effects: rash, diarrhea, trouble breathing, chest pain, severe stomach pain, mucus or blood in stool
- Serious reaction during infusion: chills, fever, itching, fast heartbeat, trouble breathing
Source: DailyMed
More on Keytruda (pembrolizumab) side effects
The following side effects have also been reported
Side effects that you should report to your care team as soon as possible:
- Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
- Dry cough, shortness of breath or trouble breathing
- Eye pain, redness, irritation, or discharge with blurry or decreased vision
- Heart muscle inflammation—unusual weakness or fatigue, shortness of breath, chest pain, fast or irregular heartbeat, dizziness, swelling of the ankles, feet, or hands
- Hormone gland problems—headache, sensitivity to light, unusual weakness or fatigue, dizziness, fast or irregular heartbeat, increased sensitivity to cold or heat, excessive sweating, constipation, hair loss, increased thirst or amount of urine, tremors or shaking, irritability
- Infusion reactions—chest pain, shortness of breath or trouble breathing, feeling faint or lightheaded
- Kidney injury (glomerulonephritis)—decrease in the amount of urine, red or dark brown urine, foamy or bubbly urine, swelling of the ankles, hands, or feet
- Liver injury—right upper belly pain, loss of appetite, nausea, light-colored stool, dark yellow or brown urine, yellowing skin or eyes, unusual weakness or fatigue
- Pain, tingling, or numbness in the hands or feet, muscle weakness, change in vision, confusion or trouble speaking, loss of balance or coordination, trouble walking, seizures
- Rash, fever, and swollen lymph nodes
- Redness, blistering, peeling, or loosening of the skin, including inside the mouth
- Sudden or severe stomach pain, bloody diarrhea, fever, nausea, vomiting
Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):
- Bone, joint, or muscle pain
- Diarrhea
- Fatigue
- Loss of appetite
- Nausea
- Skin rash
Pros and cons of Keytruda (pembrolizumab)
Pros
Recommended first-choice treatment for many types of cancers under certain situations
Less likely to cause nausea, vomiting, and hair loss (side effects that are common with traditional chemotherapy)
Given every 3 or 6 weeks, depending on the treatment plan
Uses your own immune system to attack cancer cells
Cons
Given as an injection through the veins
Might cause immune-related side effects like diarrhea, rash, and lung problems
Though rare, can cause infusion reactions
Might require you to take a break from treatment and take a corticosteroid to manage side effects
Pharmacist tips for Keytruda (pembrolizumab)
Contact your oncology care team right away if you have any immune-related side effects, like diarrhea, skin rash, or trouble breathing, at any time during your treatment with Keytruda (pembrolizumab). They could be signs that your immune system has become too active from taking the medication. You might need additional medical attention for these side effects.
Don’t take over-the-counter (OTC) medications to treat any side effects you have from Keytruda (pembrolizumab) without first contacting your oncology care team. OTC products that you might normally use won’t work as well to help with some side effects, like loperamide (Imodium-AD) for diarrhea. Instead, you might need to take a corticosteroid like prednisone to help manage side effects.
If you need to take a steroid for a few weeks to help with any side effects, don’t suddenly stop taking the steroid medication. Otherwise, you might experience uncomfortable symptoms like body aches or stomach cramps. Your care team will give you specific instructions to taper the steroid, or slowly lower the dose, to stop.
Make sure to get your lab tests done on time while you’re taking Keytruda (pembrolizumab). The lab results help your oncology care team check for possible side effects that don't typically cause symptoms, such as liver, kidney, or thyroid problems.
Though rare, you might have an infusion reaction when you’re taking Keytruda (pembrolizumab). Tell the nurse right away if you have symptoms such as chills, trouble breathing, itching, rash, or fever during your infusion. Your care team will be able to manage the reaction quickly.
Don’t breastfeed while you’re taking Keytruda (pembrolizumab) and for 4 months after your last dose. We don’t know whether the medication passes into human breast milk. But because of the risk to a nursing infant, it might be safer to find alternative feeding options.
More on Keytruda (pembrolizumab) tips
Frequently asked questions about Keytruda (pembrolizumab)
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What are the risks and warnings for Keytruda (pembrolizumab)?
Keytruda (pembrolizumab) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Immune-related side effects
Side effects from immunotherapy medications such as Keytruda (pembrolizumab) are called immune-related adverse events (irAEs). These side effects happen when your immune system becomes too active and doesn’t just attack cancer cells; it attacks healthy cells, too. Immune-related side effects can happen anywhere in your body and can happen at any time during treatment. They can range from being mild to very serious.
Some of these side events are found on your lab test results, such as liver or kidney problems. For this reason, it’s important to get your lab work done on time so your care team can monitor for these types of side effects that might not have noticeable symptoms.
Other side effects can cause recognizable symptoms, such as diarrhea, rash, and trouble breathing. Tell your care team right away if you have these symptoms or if you notice anything unusual happening to your body. Depending on how severe your symptoms are, you might need to pause or stop taking Keytruda (pembrolizumab) and take a corticosteroid to help manage them.
Infusion-related reactions
Rarely, people who take Keytruda (pembrolizumab) can have infusion reactions, including anaphylaxis. Your nurse will watch for these reactions during your infusion. But be sure to tell the nurse right away if you have chills, trouble breathing, flushing, itching, rash, or fever during your infusion.
Most of the time, pausing or slowing the infusion can help manage these infusion reactions enough that you can keep taking Keytruda (pembrolizumab). But you might need to stop taking the medication altogether if the reaction is severe.
Complications from stem cell transplants
Risk factors: People who’ve had a stem cell (bone marrow) transplant
Some people who’ve taken immunotherapy medications like Keytruda (pembrolizumab) and who’ve also had a stem cell transplant have experienced serious complications from the transplant. These problems can include veno-occlusive disease (VOD) and graft-versus-host disease (GVHD).
Before you start Keytruda (pembrolizumab), let your oncology care team know if you’ve had a stem cell transplant in the past. Also tell them if you have a stem cell transplant planned at any time after you’ve completed treatment with Keytruda (pembrolizumab). Your care team will follow up with you very closely to monitor you for signs and symptoms of these complications.
Harm to unborn baby
Risk factors: Pregnancy
Keytruda (pembrolizumab) hasn’t been studied during pregnancy in humans. But based on animal studies and the way this medication works, it could cause harm to an unborn baby when it’s given during pregnancy.
Your oncologist might ask that you take a pregnancy test before you start Keytruda (pembrolizumab) to make sure you’re not pregnant. If you’re able to become pregnant, you should use effective birth control while you’re taking this medication and for 4 months after your last dose. Let your care team know right away if you become pregnant at any time during treatment.
Keytruda (pembrolizumab) dosage forms
Typical dosing for Keytruda (pembrolizumab)
Keytruda (pembrolizumab) is given as an intravenous (IV) infusion at a medical office or infusion center. Your dose depends on your treatment plan.
Adults: The typical dose is either 200 mg given IV once every 3 weeks OR 400 mg given IV once every 6 weeks. Whether you take Keytruda (pembrolizumab) by itself or together with other anticancer therapies depends on your cancer.
Children (for certain cancers only): The dose is calculated based on body weight (kg). The typical dose is 2 mg/kg (up to a maximum of 200 mg) given IV once every 3 weeks.
What are alternatives to Keytruda (pembrolizumab)?
Certain types of:
Non-small cell lung cancer (NSCLC)
Renal cell carcinoma (kidney cancer)
Endometrial carcinoma (uterine cancer)
Cancers with high tumor mutation burden (TMB-H), high microsatellite instability (MSI-H), or deficient mismatch repair (dMMR)
Non-small cell lung cancer (NSCLC)
Pleural mesothelioma (cancer of the lining of the lungs)
Renal cell carcinoma (kidney cancer)
Certain skin cancers
Certain non-small cell lung cancers that have spread
What is the latest news about Keytruda (pembrolizumab)?
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References
Best studies we foundAmerican Cancer Society. (n.d.). Stem cell or bone marrow transplant.
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Li, K., et al. (2020). Microsatellite instability: A review of what the oncologist should know. Cancer Cell International.
Merck Sharp & Dohme LLC. (2024). Keytruda- pembrolizumab injection, powder, lyophilized, for solution; Keytruda- pembrolizumab injection, solution [package insert]. DailyMed.
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National Marrow Donor Program. (n.d.). Graft-versus-host disease basics.
Senzolo, M., et al. (2007). Veno occlusive disease: Update on clinical management. World Journal of Gastroenterology.
Zhao, P., et al. (2019). Mismatch repair deficiency/microsatellite instability-high as a predictor for anti-PD-1/PD-L1 immunotherapy efficacy. Journal of Hematology and Oncology.
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