Keytruda (pembrolizumab)

Reviewed by: HU Medical Review Board | Last reviewed: August 2023

Keytruda® (pembrolizumab) is an immunotherapy that is used to treat certain cases of non-small cell lung cancer (NSCLC) in adults. Keytruda may be used:1

  • With the chemotherapy drugs carboplatin and either paclitaxel or paclitaxel protein-bound as your first treatment when your lung cancer:
    • Has spread (advanced NSCLC), and
    • Is a type called squamous
  • Alone as your first treatment when your lung cancer:
    • Has not spread outside your chest (stage III) and you cannot have surgery or chemotherapy with radiation or
    • Your NSCLC has spread to other areas of your body (metastatic), and
    • Your tumor tests positive for PD-L1, and
    • Does not have an abnormal EGFR or ALK gene
  • Alone when:
    • You have received chemotherapy that contains platinum to treat your advanced NSCLC and it did not work or it is no longer working, and
    • Your tumor tests positive for PD-L1, and
    • If your tumor has an abnormal EGFR or ALK gene, you have also received an EGFR or ALK inhibitor medicine, and it did not work or is no longer working
  • Along with chemotherapy that contains platinum and another chemotherapy medicine:
    • Before surgery when you have early-stage NSCLC that can be removed by surgery, and
    • Then continued alone after surgery to help prevent your lung cancer from coming back
  • Alone as a treatment in adults for your lung cancer:
    • To help prevent your lung cancer from coming back after your tumor(s) has been removed by surgery and you have received platinum-based chemotherapy, and
    • You have Stage IB and your tumor(s) is 4 cm or greater in size, Stage II, or Stage IIIA NSCLC

Your doctor will perform a genetic test to find out whether Keytruda is right for you.1

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What are the ingredients in Keytruda?

The active ingredient in Keytruda is pembrolizumab.1

How does Keytruda work?

Keytruda works with your immune system to find and attack lung cancer cells. It does this by sticking to and blocking a protein called PD-L1, which plays a key role in disguising cancer cells from the immune system. By binding to and blocking PD-L1, Keytruda helps your immune system find and attack the cancer cells.1

What are the possible side effects?

The most common side effects of Keytruda when used alone include:1

  • Feeling tired (fatigue)
  • Abdominal, bone, joint, and muscle pain
  • Rash
  • Diarrhea
  • Fever
  • Cough
  • Decreased appetite
  • Shortness of breath
  • Constipation
  • Nausea
  • Low levels of thyroid hormone

The most common side effects of Keytruda with certain chemotherapy drugs include:1

  • Feeling tired (fatigue)
  • Nausea, vomiting
  • Constipation
  • Diarrhea
  • Decreased appetite
  • Rash
  • Cough
  • Trouble breathing
  • Fever,
  • Hair loss
  • Pain, weakness, and paralysis in the arms and legs
  • Swelling of the lining of the mouth, nose, eyes, throat, intestines, or vagina
  • Mouth sores
  • Headache
  • Weight loss
  • Abdominal, joint, and muscle pain
  • Trouble sleeping

These are not all the possible side effects of Keytruda. Talk to your doctor about what to expect when taking Keytruda. You also should call your doctor if you have any changes that concern you when taking Keytruda.

Other things to know

Keytruda can affect your immune system and cause it to attack normal organs and tissues. These problems may become severe or life-threatening. Before starting treatment with Keytruda, tell your doctor if you have:1

  • Immune system problems, such as Crohn's disease, ulcerative colitis, or lupus
  • Received an organ transplant
  • Received or plan to receive a stem cell transplant that uses donor stem cells (allogeneic)
  • Received radiation treatment to your chest area
  • A condition that affects your nervous system, such as myasthenia gravis or Guillain-Barré syndrome

Keytruda can harm an unborn baby. If you or your partner can become pregnant, you should use birth control during treatment and for some time after the last dose of Keytruda. You should also not breastfeed during treatment with Keytruda and for some time after the last dose. Talk to your doctor about your options for birth control and breastfeeding while taking Keytruda.1

Before beginning treatment for lung cancer, tell your doctor about all your health conditions and any other drugs, vitamins, or supplements you are taking. This includes over-the-counter drugs.

For more information, read the full prescribing information of Keytruda.