Keytruda (pembrolizumab) is a brand-name prescription medication. The Food and Drug Administration (FDA) has approved it to treat certain types of cancer in adults and some children.

Keytruda belongs to a class of biologic drugs called monoclonal antibodies. Specifically, it’s a type of monoclonal antibody called a PD-1 inhibitor. Keytruda isn’t available in a biosimilar form.

Keytruda comes as a liquid solution. Your doctor or another healthcare professional will give the drug to you by IV infusion.

For information about the dosage of Keytruda, including its strength and how the drug is given, keep reading. For a comprehensive look at Keytruda, including details about its uses, see this article.

This article describes typical dosages for Keytruda provided by the drug’s manufacturer. However, your doctor will prescribe the Keytruda dosage that’s right for you.

The information below describes typically recommended dosages for Keytruda.

Keytruda form

Keytruda comes as a liquid solution you’ll receive by IV infusion. (For details, see the “How it’s given” section below.)

Keytruda strength

Keytruda is available in one strength: 100 milligrams per 4 milliliters (mg/mL).

Typical dosages

The following information describes dosages that are commonly used or recommended. However, your doctor will prescribe the Keytruda dosage that’s right for you.

Dosage for certain cancers in adults

Keytruda is used to treat several types of cancer in adults. The recommended dosage for all Keytruda’s uses is a total of 400 mg every 6 weeks. To achieve this dosage, your doctor may give you 200 mg every 3 weeks or 400 mg every 6 weeks. Your doctor will determine the dosing schedule that’s best for you.

Depending on your condition, your doctor may give you Keytruda by itself or with other cancer treatments, such as chemotherapy. Your doctor will determine whether you’ll take Keytruda by itself or with other cancer treatments.

Children’s dosage

Keytruda is approved to treat certain cancers in children.* The recommended dosage in children is 2 mg per kilogram† of body weight (mg/kg) every 3 weeks.

Your child’s doctor will determine your child’s Keytruda dose per kg of body weight. For example, if your child weighs 18 kg (about 40 pounds [lb]), they’ll receive 36 mg every 3 weeks.

The maximum dosage is 200 mg every 3 weeks.

* Keytruda is used to treat melanoma in children ages 12 and older. For other cancers that Keytruda is used to treat in children, the drug’s prescribing information does not specify the age. To learn more about Keytruda’s approved uses in children, see this article.
† For reference, 1 kg equals about 2.2 lb.

Long-term treatment

The length of time you’ll receive Keytruda depends on certain factors. These include how your body responds to the drug and your condition.

Typically, Keytruda is not given for more than 2 years. This is because clinical trials haven’t looked at whether the drug is safe or effective if it’s used for longer than 2 years. However, if you and your doctor determine that Keytruda is safe and effective for your condition, you’ll likely continue treatment.

To find out how long you can expect to take Keytruda, talk with your doctor.

Below are some common questions about Keytruda’s dosage.

Is one dose of Keytruda more effective than the others? What are the signs Keytruda is working?

No, one dose of Keytruda is not more effective than the other doses. Both dosages* are effective at treating cancer. The choice of dosing every 3 weeks or every 6 weeks depends on your specific situation. It may be a matter of scheduling convenience.

Your doctor will monitor your condition for signs that Keytruda is working. These signs vary by the type of cancer but can include a smaller tumor size or certain blood test results.

If you have questions about Keytruda dosages or effectiveness, talk with your doctor. You can ask them how they’ll know that Keytruda is working for your condition. For details about how effective the drug is at treating different types of cancer, you can read this article.

* The recommended Keytruda dosage in adults is 200 milligrams (mg) every 3 weeks or 400 mg every 6 weeks. To learn more, refer to the “Keytruda dosage” section above.

Does Keytruda have a recommended dosing schedule?

Yes, Keytruda has a recommended dosing schedule. You’ll receive the drug every 3 weeks or every 6 weeks. Your schedule depends on the dose your doctor prescribes. To learn more, refer to the “Keytruda dosage” section above.

If you have questions about your Keytruda dosing schedule, talk with your doctor.

Keytruda comes as a liquid solution for IV infusion. Your doctor or another healthcare professional will give the drug to you at an infusion center or a hospital. The infusion takes about 30 minutes.

If you have questions about how Keytruda is given, talk with your doctor.

If you miss an appointment for your Keytruda dose, call your doctor’s office right away. They can reschedule your appointment and adjust your dosing schedule if necessary.

To help make sure that you don’t miss an appointment, try using a medication reminder. This can include setting an alarm or using a timer. You could also download a reminder app on your phone.

The dosages in this article are typical dosages provided by the drug manufacturer. If your doctor recommends Keytruda for you, they’ll prescribe the dosage that’s right for you.

If you have questions about the dosage of Keytruda that’s best for you, talk with your doctor.

Besides learning about dosage, you may want other information about Keytruda. These additional articles might be helpful:

  • More about Keytruda. For information about other aspects of Keytruda, refer to this article.
  • Side effects. To learn about side effects of Keytruda, see this article. You can also look at the Keytruda prescribing information.
  • Drug comparison. Find out how Keytruda compares with Opdivo and Imfinzi.
  • Cost. For information about the price of Keytruda, see this article.
  • Details about your condition. For details about certain cancers, see our cancer hub.

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.