If you have cancer, you know it may be tough to sort through your treatment options with your health care team and figure out what’s best for you. You may discover new options you want to consider.
One of those options is pembrolizumab (Keytruda). Crystal Lee, a pharmacist with Banner MD Anderson Cancer Center, shared some information you should know if you’re prescribed this medication as part of your cancer treatment plan.
What is pembrolizumab (Keytruda)?
Pembrolizumab is an immunotherapy drug. It helps your body's immune system detect and eliminate cancer cells. It belongs to a class of drugs called immune checkpoint inhibitors and it works by blocking the PD-1 pathway, which helps keep immune cells from harming normal cells. By blocking it, pembrolizumab allows your immune system to recognize and destroy cancer cells more effectively.
Dr. Lee explained that pembrolizumab works by training your immune system to better recognize cancer in the body. “It’s like cancer can hide from your immune system by waving a flag that says that it’s a normal part of your body. When your immune system sees this flag, it is tricked into believing that the cancer belongs where it is, so it ignores the cancer,” she said.
Pembrolizumab covers the flag, so your immune system sees cancer cells as something your body needs to eliminate.
Benefits of pembrolizumab
Pembrolizumab is approved to treat several different types of cancer. It can be used alone or in combination with other cancer treatments, such as chemotherapy, depending on the stage and type of cancer.
You may be a candidate for pembrolizumab if you have:
- Advanced or metastatic melanoma, non-small cell lung cancer, head and neck cancers, Hodgkin lymphoma, kidney cancer or bladder cancer.
- Not responded well to or been able to tolerate other treatments like chemotherapy or radiation.
- Cancer with the biomarker PD-L1 (the flag in the example above).
“Talk to your oncologist to find out if this is the right medication for you. Pembrolizumab cannot be used for every cancer type — it must be used for specific types of cancer. You may need additional testing to make sure you are a good candidate,” Dr. Lee said.
How to use pembrolizumab
Pembrolizumab is administered via intravenous (IV) infusion in a health care center. Most people are scheduled for an infusion every three or six weeks. The infusion itself takes about 30 minutes, so you may want to bring a book, music or other type of entertainment.
Drink plenty of water before and after your session so you stay hydrated and let your health care team know if you have any new or unusual symptoms afterward.
Possible side effects
Like all medications, pembrolizumab can cause side effects which may range from mild to severe.
“Side effects are caused by your immune system accidentally harming normal cells in your body. They can occur anywhere in the body,” Dr. Lee said. “The timing of side effects may be different from what you usually expect from medications. It often can take several weeks to start to see side effects. Some side effects tend to occur earlier in therapy, but others could take months to appear.”
Common side effects include:
- Fatigue
- Rash or itching
- Diarrhea
- Thyroid problems
- Liver inflammation (hepatitis)
“Keep track of any side effects in a journal,” Dr. Lee said. “Things that may feel minor but last over time may need follow-up from a provider to see whether they could be related to pembrolizumab.”
Serious but less-common immune-related side effects include:
- Lung inflammation (pneumonitis)
- Kidney irritation (nephritis)
- Inflammation of the intestines (colitis)
- Pancreas irritation (pancreatitis)
If you experience symptoms of serious side effects like shortness of breath, severe abdominal pain or symptoms of infection like fever or chills, contact your health care provider right away.
Precautions and warnings
Before you start taking pembrolizumab, discuss your full medical history with your health care provider. Let your provider know about any prescription or over-the-counter (OTC) medications, supplements or herbal products you take, since some can interact with the drug.
People with autoimmune diseases like lupus or rheumatoid arthritis or who have had an organ transplant should be cautious since this medication could make these conditions worse.
“Because pembrolizumab could cause hepatitis, avoid things that could harm your liver, such as excessive alcohol, more than four grams of acetaminophen (Tylenol) per day and some herbal supplements or alternative medications,” Dr. Lee said.
You’ll need to have regular check-ups to see how your body is responding to the treatment. Your provider may recommend blood tests or scans to see how well the medication is working.
Make sure any providers you see know you are taking pembrolizumab in case they are considering prescribing medications. For example, steroids that you take by mouth or IV, like prednisone, methylprednisone or dexamethasone, might reduce the effectiveness of the drug. “Providers usually recommend avoiding them unless there is no other alternative,” Dr. Lee said.
Steroid creams, ointments, inhalers and joint injections are generally OK to use when you’re taking pembrolizumab.
Lifestyle tips during cancer treatment
Pembrolizumab can help treat cancer but you can also take steps to manage your overall health during treatment:
- Focus on a balanced diet rich in fruits, vegetables, whole grains and lean proteins to help support your immune system.
- Stay active. Gentle exercise like walking or yoga can help manage fatigue and improve your mood. But listen to your body and rest when you need to.
- Consider joining a support group or speaking with a counselor to manage stress. Cancer treatment can be emotionally challenging.
The bottom line
Pembrolizumab (Keytruda) is a promising immunotherapy medication that may help treat some types of advanced cancer. It boosts your body’s natural defenses, so it’s different than other cancer treatments like chemotherapy or radiation.
If you think pembrolizumab might be an option for you, talk to your health care provider or an expert at Banner Health to discuss your options and create a personalized treatment plan.
Other useful articles
- Cancer: Understanding Remission, Cancer-Free and Other Terms
- Understanding Common Side Effects of Cancer Treatments
- Sticking with Medication When Side Effects Get in the Way
The content in this article is for informational use only. Always discuss any medication with your health care provider or pharmacist before taking it. Also, refer to the medication package insert supplied by the pharmaceutical manufacturer with your prescription.
