Key takeaways
- Imfinzi (durvalumab) and Keytruda (pembrolizumab) are prescription drugs used to treat various forms of cancer.
- Both drugs are administered as intravenous (IV) infusion into a vein.
- Your dosage for each drug varies depending on the cancer being treated.
This article explains some ways Imfinzi and Keytruda are alike and different. Your doctor can discuss the benefits and risks of these and other treatment options based on your individual diagnosis and medical history.
Imfinzi and Keytruda are immunotherapy medications, available only by prescription. They work by activating your immune system to recognize and attack cancer cells.
Imfinzi and Keytruda are also biologic drugs. A biologic is made from parts of living organisms. At this time, there are no biosimilar forms for Imfinzi or Keytruda. Biosimilars are like generic drugs. But unlike generics, which are made for nonbiologic drugs, biosimilars are made for biologic drugs.
- Imfinzi:
- Available as a biosimilar: no
- Active ingredient: durvalumab
- Keytruda:
- Available as a biosimilar: no
- Active ingredient: pembrolizumab
Imfinzi and Keytruda are used to treat some of the same types of cancers in adults. These cancers are:
- non-small cell lung cancer (NSCLC), the most common type of lung cancer
- some forms of biliary tract cancers, including gallbladder cancer
- hepatocellular carcinoma (HCC), the most common type of liver cancer
- some forms of endometrial cancer (the most common type of uterine cancer)
- gastroesophageal junction adenocarcinoma (a type of cancer the forms where the esophagus meets the stomach)
In addition, Keytruda is used to treat additional types of cancer in adults
- bladder cancer
- certain skin cancers
- head and neck cancer
- certain lymphomas
- stomach cancer
- esophageal cancer
- cervical cancer
- endometrial cancer
- liver cancer
- kidney cancer
- triple-negative breast cancer
- colorectal cancer
- solid tumors with certain genetic changes
- malignant pleural mesothelioma
Imfinzi and Keytruda aren’t recommended for all types of each of the cancers listed above. Additional factors will decide whether Imfinzi or Keytruda are good options for you.
Keytruda is used to treat some types of cancer in children. Imfinzi is not used in children.
For more information about Keytruda and children, talk with your child’s doctor.
You’ll receive Imfinzi or Keytruda at your doctor’s office or hospital. It’s given as an intravenous (IV) infusion. With IV infusions, medications are slowly injected through a needle placed in your vein.
Both drugs come in vials of solution that a healthcare professional uses to prepare your IV infusion.
Imfinzi infusions are generally repeated every 2, 3, or 4 weeks. Each Imfinizi infusion will take about an hour.
Keytruda infusions are typically given every 3 or 6 weeks. With Keytruda, each IV infusion will last around 30 minutes.
Your doctor will discuss the details of your dosage with you. Your schedule may depend on the type of cancer you’re getting treated for and if you’re also receiving chemotherapy.
Some people taking Imfinzi and Keytruda may experience mild to serious side effects. For more information about possible side effects, see the prescribing information for Imfinzi and Keytruda.
Mild side effects
Imfinzi and Keytruda may cause mild side effects in some people. The following tablet lists examples of mild side effects that can occur with these drugs.
| Imfinzi | Keytruda | |
| fatigue | X | X |
| feeling weak | X | X |
| muscle or bone pain | X | X |
| constipation | X | X |
| decreased appetite | X | X |
| nausea | X | X |
| swelling in arms or legs | X | |
| urinary tract infection (UTI) | X | |
| cough | X | X |
| upper respiratory tract infection | X | |
| shortness of breath | X | X |
| rash | X | X |
| hair loss | X | X |
| itchy skin | X | X |
| diarrhea | X | X |
| fever | X | X |
| belly pain | X | X |
This chart may not include all mild side effects of these drugs. Other mild side effects may occur if you’re receiving Imfinzi or Keytruda with other cancer treatments.
For more information on mild side effects of these drugs, see the prescribing information for Imfinzi and Keytruda.
Serious side effects
Serious side effects may occur in people receiving Imfinzi or Keytruda. The following table includes serious side effects reported with these drugs.
| Imfinzi | Keytruda | |
| severe immune system reactions | X | X |
| severe infusion reactions | X | X |
| serious infections, such as pneumonia | X | X |
| severe skin rash | X | X |
If you have questions about your specific risk for side effects of Imfinzi or Keytruda, talk with your doctor.
Allergic reactionFor some people, Imfinzi and Keytruda can cause an allergic reaction.
It’s not clear whether this side effect occurred in the Imfinzi drug’s studies. But it is reported in the Keytruda drug studies.
In general, symptoms of an allergic reaction can be mild or serious.What might help
If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms and can determine whether you should keep taking Imfinzi or Keytruda.
If you have symptoms of a severe allergic reaction, such as swelling or difficulty breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.
If your doctor confirms you’ve had a serious allergic reaction to Imfinzi or Keytruda, they may have you switch to a different treatment.
You may wonder whether Imfinzi or Keytruda would help your condition.
Whether you have health insurance or not, cost may be a factor when you’re considering these drugs.
For more details about the cost of these drugs, see the Imfinzi cost article and Keytruda cost article.
Keep in mind that what you’ll pay for either drug will depend on your treatment plan, health insurance, and the location where you receive the drug.
Imfinzi or Keytruda may not be right for you if you have certain medical conditions or other factors that affect your health. Talk with your doctor about your health history before you take either drug.
Before taking Imfinzi or Keytruda, talk with your doctor if you have any of the following conditions or health factors.
- Warnings for both Imfinzi and Keytruda:
- autoimmune disease
- organ transplant
- stem cell treatment
- lung or liver problems, including breathing problems
- previous radiation history
- pregnancy
- breastfeeding
- Warnings for Imfinzi:
- current infection
- Warnings for Keytruda:
- certain multiple myeloma treatments
- nervous system problems, such as myasthenia gravis
The short answer: It’s not likely.
Details: There aren’t any studies on switching between Imfinzi and Keytruda. So it isn’t known if it’s safe and effective to switch between these drugs.
Imfinzi and Keytruda both stay in your system for several months after your last dose. It could be harmful to have both of these drugs in your system at the same time.
If you have a severe immune system reaction to one of these drugs, it’s possible that you would have a similar reaction to the other. Studies are needed to learn more about the safety of switching these medications.
You should not switch drugs or stop your current treatment unless your doctor tells you it’s fine to do so. Discuss the risks and benefits with your doctor if there’s a reason that you’re interested in switching your medication.
Disclaimer: Healthline 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.