This product is manufactured by Merck Canada using the ingredient pembrolizumab.

This product is taken via intravenous injection.

Why is it prescribed?

Pembrolizumab is used for treatment of certain cases of metastatic non-small cell lung cancer where tumours express PD-L1; when the cancer has spread or cannot be removed by surgery or where  tumours have an abnormal "EGFR" or "ALK" gene, and chemotherapy that contains platinum and an EGFR or ALK inhibitor medicine have already been tried.


Contact your health care provider immediately, if you should experience any of the following symptoms:

  • Fever of 100.4° F (38° or higher, chills)
  • Signs of reaction to the drug (wheezing, chest tightness, itching, bad cough, swelling of the face, lips, tongue or throat)
  • New or worsening cough, chest pain, or shortness of breath
  • Diarrhea or severe abdominal pain, especially right side
  • Blood in your stools or dark stools
  • Skin or the whites of your eyes turn yellow
  • Persistent or unusual headache, extreme weakness, dizziness or fainting, or vision changes

The following symptoms require medical attention, but are not an emergency.:

  • Unable to eat or drink for 24 hours or have signs of dehydration: tiredness, thirst, dry mouth, dark and decrease amount of urine, or dizziness
  • Urine turns dark or brown (tea color)
  • Decreased appetite
  • Skin rash with or without itching
  • Sores in the mouth
  • Skin blisters and/or peels
  • Numbness or tingling in hands or feet
  • Bleed or bruise more easily than normal
  • Nausea (interferes with ability to eat and unrelieved with prescribed medication)
  • Vomiting (vomiting more than 4-5 times in a 24 hour period)


See other products used in the treatment of •non-small cell lung cancer •

For previously untreated and treated Metastatic Non Small Cell Lung Cancer the recommended dose is 200 mg.

Keytruda® is administered through an infusion into a vein (IV) for about 30 minutes. It is usually given every 3 weeks. Your doctor will decide how many treatments you need.


Pembrolizumab is a monoclonal antibody. used as a type of “targeted” cancer therapy.

Antibodies are an important part of the body’s immune system. Normally, the body creates antibodies in response to an antigen (a foreign substance) that has entered the body. The antibodies attach to the antigen. The immune system then knows that this should be destroyed.

Scientists have identified specific antigens on the surface of certain lung cancer cells and have created a specific antibody that will attach to those antigens. When given to the patient, these monoclonal antibodies will attach to matching antigens like a key fits a lock. Since monoclonal antibodies target only specific cells, they may cause less toxicity to healthy cells than the traditional cancer treatments.  Monoclonal antibody therapy is usually only given for cancers in which antigens (and the respective antibodies) have been identified already.

Pembrolizumab is a highly selective monoclonal antibody that is used to treat very specific types of non-small cell lung cancer.  

Very common:

  • diarrhea, nausea
  • itching, rash
  • joint pain
  • feeling unusually tired or weak
  • fever
  • feeling less hungry
  • shortness of breath
  • patches of skin which have lost colour (vitiligo)

Common :

  • flu-like illness
  • dry mouth
  • headache
  • change in your sense of taste
  • cough
  • lack of white blood cells
  • rapid heart beat
  • cold sores
  • upper respiratory tract infection
  • stuffy nose
  • stomach pain, constipation, vomiting, inflammation of the mucous membrane in the mouth dry skin, redness of the skin, red raised skin rash
  • back pain, muscle aches
  • chills
  • swelling of the face, legs or arms

Do not use pembrolizumab if you allergic to any components of the medication.

Discuss use of pembrolizumab with your health-care providers because of potential problems if:

  • you have an autoimmune disease (a condition where the body attacks its own cells), such as Crohn’s disease, Ulcerative Colitis or Lupus
  • you have pneumonia or inflammation of your lungs
  • you had an allergic reaction to other monoclonal antibody therapies
  • you have or have had chronic viral infection of the liver, including hepatitis B (HBV) or hepatitis C (HCV)
  • you have HIV infection or AIDS
  • you have liver damage or have had a liver transplant
  • you have kidney damage or have had a kidney transplant
  • you have had a solid organ transplant or a bone marrow (stem cell) transplant that used donor stem cells (allogeneic)

Drug interactions:

  • Discuss use of pembrolizumab with your healthcare team if you take other medicines that make your immune system weak such as prednisone.

Use in pregnancy: Pembrolizumab may be hazardous to the fetus and should not be used in pregnancy. Women must use effective contraception while being treated with pembrolizumab and
for at least 4 months after the last dose.

Use in breastfeeding: Use is not recommended if breastfeeding.



Page Last Updated: 05/10/2016