Key Takeaways

  • Imfinzi (durvalumab) is a prescription drug used to treat certain types of cancer.
  • More common side effects in people receiving Imfinzi include fatigue, nausea, skin rash, and abdominal pain.
  • In rare cases, some people may experience serious side effects from Imfinzi, such as difficulty breathing.

Specifically, Imfinzi is prescribed for certain adults with:

The active ingredient in Imfinzi is durvalumab. Imfinzi comes as a liquid solution that’s given as an intravenous (IV) infusion. This is an injection into a vein over a period of time. You’ll receive Imfinzi infusions at a clinic or in the hospital.

Imfinzi is an immunotherapy drug, which means it works with your immune system to attack cancer cells. It belongs to a group of medications called biologics, which are drugs made from living cells.

Keep reading to learn about common, mild, and serious side effects that Imfinzi can cause.

Here are some of the more common side effects reported by people who were treated with Imfinzi.

These side effects can vary depending on what condition the drug is being used to treat. The side effects can also vary depending on whether Imfinzi is used alone or in combination with other drugs.

More common side effects in people receiving Imfinzi include:

  • fatigue (lack of energy)
  • nausea
  • skin rash (see “Tips for managing side effects”)
  • abdominal pain

Imfinzi can cause mild side effects in some people. These side effects can vary depending on the condition Imfinzi is being used to treat.

Examples of mild side effects that have been reported with Imfinzi include:

  • cough (see “Tips for managing side effects”)
  • muscle pain
  • fever
  • diarrhea
  • nausea
  • abdominal pain
  • hair loss (see “Tips for managing side effects”)
  • hyperthyroidism (overactive thyroid)
  • hypothyroidism (underactive thyroid)
  • mild skin rash (see “Tips for managing side effects”)

In most cases, these side effects should be temporary. And some may be easily managed, too. But if you have any symptoms that are ongoing or that bother you, talk with your doctor or pharmacist. And don’t stop using Imfinzi unless your doctor recommends it.

Imfinzi may cause mild side effects other than the ones listed previously. See Imfinzi’s prescribing information.

In rare cases, some people may experience serious side effects from Imfinzi. Serious side effects that have been reported with Imfinzi include:

For more information, you can refer to Imfinzi’s prescribing information.

If you develop serious side effects while using Imfinzi, call your doctor right away. If the side effects seem life threatening or if you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. Sharing your experience helps make medication safer for everyone by giving doctors and researchers more information about how the drug works in real life. If you develop a side effect while receiving Imfinzi and want to tell the FDA about it, visit MedWatch or call 800-FDA-1088.

Allergic reaction

For some people, Imfinzi can cause an allergic reaction. But it’s not clear whether this side effect occurred in 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 continue Imfinzi treatment.

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, they may have you switch to a different treatment.

There may be things you can do to help make certain Imfinzi side effects more manageable. If you have ongoing, worsening, or bothersome side effects, talk with your doctor or pharmacist. They can suggest tips for managing them or recommend other available treatment options for your condition.

Note: The side effects reported in studies occurred in people who received Imfinzi with chemotherapy. So it’s unknown whether Imfinzi or the chemotherapy caused certain side effects. If you have questions, talk with your doctor.

Hair loss

Some people may experience hair loss during Imfinzi treatment. In studies, this was a common side effect reported in people receiving Imfinzi along with chemotherapy for small cell lung cancer.

According to studies, hair loss also did not occur during Imfinzi treatment for hepatocellular carcinoma or biliary tract cancer.

Chemotherapy drugs often cause hair loss. So, it’s not known whether Imfinzi caused the hair loss or whether it was due to the chemotherapy.

In studies, hair loss wasn’t reported in people receiving Imfinzi for non-small cell lung cancer.

What might help

If you experience hair loss that concerns you during your Imfinzi treatment, talk with your doctor. They may be able to help you determine the cause and the best ways to treat it.

Skin rash

Some people may develop a rash during Imfinzi treatment. According to studies, rash was one of the most common side effects that people reported.

In some rare cases, Imfinzi may cause a very serious rash, such as SJS or drug rash with eosinophilia and systemic symptoms (DRESS). These conditions can even be life threatening, so it’s important to treat them right away. Symptoms may include:

  • fever
  • blistering in your mouth, nose, or eyes
  • blistering rash that’s red, purple, or discolored

What might help

If you develop symptoms of a rash, see your doctor right away. They can recommend creams or other medications to treat the rash so it doesn’t get worse. They can also determine how serious your rash is.

If you develop a more serious rash, such as SJS or DRESS, you may need to receive treatment in a hospital. That’s because these conditions can be life threatening. Your doctor may also have you stop treatment with Imfinzi and switch to a different treatment.

If you have questions or concerns about developing a rash during Imfinzi treatment, talk with your doctor.

Infusion reactions

In rare cases, Imfinzi may cause infusion reactions. These are reactions that cause symptoms similar to those of an allergic reaction. They may occur during or after your infusion.

Keep in mind that Imfinzi is given as an intravenous (IV) infusion. This is an injection into a vein over a period of time.

In some cases, these reactions may be serious or even life threatening. Symptoms may include:

What might help

If you experience symptoms of an infusion reaction during or after an infusion, tell your doctor right away. In some cases, these reactions can be serious or even life threatening.

Your doctor may recommend that your current infusion be slowed down or stopped until your symptoms ease. In some cases, your doctor may recommend that you stop Imfinzi treatment and switch to a different medication.

Cough

Imfinzi may cause a cough in some people. According to studies, coughing was a common side effect reported in people receiving Imfinzi.

What might help

If you develop a cough, talk with your doctor right away. They’ll check to make sure your cough isn’t from an immune system condition called pneumonitis (swelling in your lungs). Your doctor can determine the cause of your cough and the best way to treat it.

If you have concerns about developing a cough during Imfinzi treatment, talk with your doctor.

Keeping track of side effects

During your Imfinzi treatment, consider keeping notes on any side effects you’re having. Then, you can share this information with your doctor. This is especially helpful when you first start taking new drugs or using a combination of treatments.

Your side effect notes can include things such as:

  • what dose of drug you were receiving when you had the side effect
  • how soon after starting that dose you had the side effect
  • what your symptoms were from the side effect
  • how it affected your daily activities
  • what other medications you were also taking
  • any other information you feel is important

Keeping notes and sharing them with your doctor will help your doctor learn more about how this drug affects you. Your doctor can use this information to adjust your treatment plan if needed.

Get answers to some frequently asked questions about Imfinzi’s side effects.

Will I have side effects after stopping Imfinzi?

It’s not likely. Withdrawal symptoms weren’t reported in Imfinzi’s studies. These are symptoms that happen when you stop taking a drug your body has become dependent on. (With dependence, your body needs a drug in order to function as usual.)

That said, your condition may worsen if you stop treatment with Imfinzi before your doctor advises doing so. Be sure to talk with your doctor before stopping treatment. They can recommend whether this is best for you.

How long will I have side effects from Imfinzi?

That can differ between people. After you receive your last dose of Imfinzi, the drug can stay in your body for about 3 months. During this time, your body will break down and clear most of the drug from your system.

Most side effects of Imfinzi may go away before this length of time. But some people may have certain side effects until their body fully clears the drug.

If you have questions about how long you might have side effects from Imfinzi, talk with your doctor or pharmacist.

Is there a higher risk of side effects if Imfinzi is used with other medications, such as chemotherapy drugs?

It depends. Imfinzi is usually given with other chemotherapy drugs. In studies of Imfinzi, the reported rates of side effects were in people who received Imfinzi with chemotherapy. But if you’re receiving a different type of chemotherapy than the one used in studies, you may have different side effects. You may also have a higher risk for certain side effects.

If you have questions about your risk for side effects with your specific treatment plan, talk with your doctor.

Before using Imfinzi, discuss your health history with your doctor. Imfinzi may not be right for you if you have certain medical conditions or other factors affecting your health. Be sure to talk with your doctor if any of the following apply to you: