Imfinzi (durvalumab)

Medically Reviewed By Dena Westphalen, Pharm.D.

About Imfinzi

Imfinzi is a brand-name prescription medication. It’s approved by the Food and Drug Administration (FDA) to treat the following lung cancers in adults.

  • Small cell lung cancer (SCLC). SCLC is a fast-growing type of lung cancer. Doctors prescribe Imfinzi as the first treatment for extensive SCLC. (With this type of SCLC, the cancer has spread to both lungs or areas of the body outside of the lungs.) For this purpose, Imfinzi is used in combination with certain chemotherapy drugs.
  • Non-small cell lung cancer (NSCLC). NSCLC is a slow-growing type of lung cancer. Doctors prescribe Imfinzi to treat stage 3 NSCLC that cannot be removed with surgery. (With this type of NSCLC, the cancer has spread to the lymph nodes and other areas of the body outside of the lungs.) In addition, the NSCLC must not have worsened after treatment with radiation and certain chemotherapy drugs.

For details about these conditions and how the drug treats them, see the “Imfinzi: Uses” section below.

Key points

The following table provides key facts about Imfinzi.

Active drug durvalumab
Drug class immunotherapy drug, which means it works with the immune system to fight off cancer
Form solution that’s given as an IV infusion

Finding a healthcare professional

If you’re interested in taking this drug, search here to find a doctor who might prescribe it.

Imfinzi: Generic or biosimilar

Imfinzi is a brand-name medication. It contains the active drug durvalumab, which is a biologic drug

It isn’t currently available in a biosimilar form. A biosimilar is a drug that’s similar to its brand-name parent drug.

Traditional drugs are made from chemicals. They have generics, which are identical copies of the active drug found in brand-name medications.

However, biologics are made from parts of living cells. As a result, it’s not possible to make exact copies of biologics. So instead of generics, biologic drugs have biosimilars.

Biosimilars are considered as effective and safe as their parent drugs. As with generics, biosimilars may cost less than brand-name drugs.

Imfinzi: Side effects

As with most drugs, it’s possible to have side effects with Imfinzi. These can include some mild side effects but also some serious ones.

To learn more about Imfinzi’s side effects, talk with your doctor or pharmacist. They may also provide information about managing certain side effects of this drug.

Note: The Food and Drug Administration (FDA) tracks side effects of drugs it has approved. If you would like to notify the FDA about a side effect you’ve had with Imfinzi, you can do so through MedWatch.

Mild and serious side effects

Mild and serious side effects of Imfinzi are listed below. This article does not include all of Imfinzi’s possible side effects.

Mild side effects

Mild side effects* of Imfinzi may include:

  • fatigue or weakness
  • cough
  • upper respiratory infection, such as sinus infection or the common cold
  • shortness of breath
  • digestive problems, such as loss of appetite, abdominal pain, nausea, constipation, vomiting, or diarrhea
  • hair loss
  • rash
  • mild allergic reaction

Most times, mild side effects of a drug go away within a few days or a couple of weeks. Talk with your doctor or pharmacist if any side effects become severe or don’t go away.

* This is not a complete list of Imfinzi’s mild side effects. To learn about other mild side effects of this drug, ask your doctor or pharmacist. Or you can view the drug’s prescribing information.
† To learn more about allergic reaction, see below. An allergic reaction is possible after taking Imfinzi. However, this side effect wasn’t reported in clinical studies.

Serious side effects

Serious side effects of Imfinzi may include:

Serious side effects from Imfinzi aren’t common, but they are possible. If you have serious side effects, call your doctor right away. However, if you’re having a medical emergency or your symptoms feel life threatening, call 911 or a local emergency number.

* To learn more about allergic reaction, see below. An allergic reaction is possible after taking Imfinzi. However, this side effect wasn’t reported in clinical studies.

Allergic reaction

As with most drugs, some people can have an allergic reaction after taking Imfinzi. A more severe allergic reaction is rare but possible.

Although this side effect wasn’t reported in clinical studies of Imfinzi, it can still happen.

Possible symptoms of mild and serious allergic reactions are listed in the table below.

Mild allergic reaction symptoms Serious allergic reaction symptoms
flushing • swelling under your skin, possibly in your hands, feet, lips, or eyelids
rash • swelling in your throat or mouth
• itching trouble breathing

If you have an allergic reaction to Imfinzi, call your doctor right away. This is important because the reaction could become severe.

However, if you’re having a medical emergency or your symptoms feel life threatening, call 911 or a local emergency number.

Imfinzi: Uses

Prescription drugs, such as Imfinzi, are approved by the Food and Drug Administration (FDA) to treat certain conditions. Doctors sometimes prescribe drugs off-label for other conditions. With off-label use, doctors prescribe a drug for a purpose other than what it’s approved for.

Using Imfinzi for small cell lung cancer (SCLC)

The FDA has approved Imfinzi to treat a certain type of small cell lung cancer (SCLC) in adults.

Doctors prescribe Imfinzi as the first treatment for extensive SCLC. (With this type of SCLC, the cancer has spread to both lungs or areas of the body outside of the lungs.) For this purpose, Imfinzi is used in combination with certain chemotherapy drugs. These include etoposide and either cisplatin or carboplatin.

About SCLC

SCLC is a fast-growing type of lung cancer. It’s called “small cell” because the cancer cells are small when viewed under a microscope.

Possible symptoms of SCLC include:

  • persistent cough that worsens over time
  • wheezing
  • fatigue
  • hoarse voice
  • weight loss

Using Imfinzi for non-small cell lung cancer (NSCLC)

The FDA has approved Imfinzi to treat a certain type of non-small cell lung cancer (NSCLC) in adults.

Doctors prescribe Imfinzi to treat stage 3 NSCLC that cannot be removed with surgery. (With this type of NSCLC, the cancer has spread to the lymph nodes and other areas of the body outside of the lungs.) In addition, the NSCLC must not have worsened after treatment with radiation and certain chemotherapy drugs known as platinum-based chemotherapy. Examples of these drugs include oxaliplatin, carboplatin, and cisplatin.

About NSCLC

NSCLC is a slow-growing type of lung cancer. It’s called “non-small cell” because the cancer cells appear larger than those of small cell lung cancer (SCLC)* when viewed under a microscope.

Symptoms that may occur with NSCLC include:

  • persistent cough that worsens over time
  • wheezing
  • fatigue
  • hoarse voice
  • weight loss

* For details about SCLC, see “Using Imfinzi for small cell lung cancer (SCLC)” above.

Using Imfinzi with other drugs

When used to treat SCLC, doctors typically prescribe Imfinzi in combination with certain chemotherapy drugs. These include etoposide and either cisplatin or carboplatin.

For NSCLC, your doctor can recommend whether Imfinzi will be used alone or in combination with other treatments.

Using Imfinzi in children

Doctors typically won’t prescribe Imfinzi for children. The drug is only approved for use in adults.

Finding a healthcare professional for Imfinzi

If you’re interested in using Imfinzi for your condition, you can find a doctor who might prescribe it by searching here. You can also prepare for your appointment by visiting Healthgrades’ appointment guide for lung cancer.

Imfinzi: How it works

Imfinzi is used to treat small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) in adults. To learn more about these conditions, see the “Imfinzi: Uses” section above.

Imfinzi is an immunotherapy drug. Its mechanism of action (how it works) is to help your immune system to fight lung cancer. Imfinzi does this by attaching to certain receptors (attachment sites) on cancer cells.

When certain proteins attach to these receptors, cancer cells can hide from your immune system. By attaching to these receptors, Imfinzi keeps other proteins from attaching to them. This helps make cancer cells more visible to your immune system. As a result, your immune system is better able to recognize and attack cancer cells. This is how Imfinzi works with your immune system to fight off lung cancer.

How long does Imfinzi take to start working?

Imfinzi starts working in your body when you receive your first IV infusion. However, you won’t notice Imfinzi working in your body. Your doctor will give you tests during treatment to check if Imfinzi is working to treat your lung cancer.

How long does Imfinzi work?

How long Imfinzi will work can depend on many factors, including which type of lung cancer you’re using it to treat.

In clinical studies, the length of time Imfinzi worked varied between people with SCLC and NSCLC. In these studies, people taking Imfinzi generally lived longer than people taking other cancer treatments or a placebo. (A treatment with no active drug is called a placebo.)

Keep in mind that everyone’s situation is unique, and how long Imfinzi will work may not match the results seen in clinical studies. If you have questions about how long Imfinzi will work, talk with your doctor.  

How long does Imfinzi stay in your system?

Imfinzi likely stays in your system for about 3 months.

This is based on Imfinzi’s half-life. (A drug’s half-life is the amount of time it takes your body to get rid of half of a drug’s dose.) Imfinzi’s half-life is about 18 days. This means it takes about 18 days for your body to get rid of half of a dose of Imfinzi.

It usually takes about five half-lives for your body to get rid of a drug completely. For Imfinzi, this means the drug stays in your system for about 90 days.

Imfinzi: Alternatives

Doctors may prescribe drugs other than Imfinzi for your condition. Certain drugs may work better for you than others.

Imfinzi is used to treat certain types of lung cancer. Here’s a summary of other drugs that doctors sometimes prescribe for this condition.

Imfinzi vs. Keytruda and other drugs

To learn more about some alternatives of Imfinzi, view the following articles:

For additional information about alternatives to Imfinzi, ask your doctor. They can tell you about other medications they could prescribe for your condition.

Imfinzi: Cost

As with other medications, prices for Imfinzi may vary. The drug’s price will depend on factors such as:

Cost considerations for Imfinzi

Here are some things to consider when looking into the cost of Imfinzi.

Need for prior authorization. Before insurance coverage for Imfinzi is approved, your insurance company may require prior authorization. In this case, your doctor and insurance company will communicate about your prescription for Imfinzi. Then, the insurance company will decide if the drug will be covered. To find out if you need prior authorization for Imfinzi, contact your insurance company.

Possible cost assistance options. Financial assistance to help lower the cost of Imfinzi is available. The Access 360 program for Imfinzi may help reduce its cost. To learn more and see if you’re eligible for support, call 844-ASK-A360 (844-275-2360) or visit the program website. Also, check out this article to learn about ways to save on prescription drugs.

Use of a specialty pharmacy. Imfinzi is only dispensed from specialty pharmacies. These pharmacies are authorized to handle certain drugs considered specialty medications. These medications may be expensive or require help from healthcare professionals to be used safely and effectively. Ask your doctor which specialty pharmacy they’ll prescribe Imfinzi through.

Availability of a biosimilar form. Imfinzi doesn’t come in a biosimilar form. A biosimilar is a drug that’s similar to a brand-name biologic drug. Biosimilars may cost less than brand-name drugs.

Imfinzi: Dosage

Below, you’ll find dosages that are commonly recommended for Imfinzi. However, you should take the dosage your doctor prescribes for you. They’ll recommend the dosage that’s best for your needs.

The dosage of Imfinzi that your doctor prescribes will depend on factors such as:

  • your body weight
  • the side effects you may have
  • the condition you’re using Imfinzi to treat and the severity of the condition

Imfinzi’s forms and strengths

Imfinzi is available as follows.

  • Form: solution that’s given as an IV infusion
  • Strengths:
    • 120 milligrams (mg) per 2.4 milliliters (mL)
    • 500 mg per 10 mL

Imfinzi’s recommended dosages

Imfinzi is approved to treat small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) in adults. To learn more about these conditions, see the “Imfinzi: Uses” section above.

Recommended dosages for Imfinzi are described below. Certain dosages are based on a person’s weight in kilograms (kg). One kg is about 2.2 pounds (lb).

Dosage for SCLC

Recommended dosages of Imfinzi for SCLC are as follows.

Body weight Starting dosage Maintenance dosage
less than 30 kg (about 66 lb) 20 mg/kg* once every 3 weeks for 4 doses 10 mg/kg† once every 2 weeks
30 kg (about 66 lb) or more 1,500 mg once every 3 weeks for 4 doses 1,500 mg once every 4 weeks

* For example, a person weighing 25 kg (about 55 lb) would receive a dose of 250 mg.
† For example, a person weighing 25 kg (about 55 lb) would receive a dose of 250 mg.

Dosage for NSCLC

When used for NSCLC, Imfinzi may be given biweekly (once every 2 weeks) or monthly. Your doctor can recommend the dosing schedule that’s right for you.

Recommended dosages of Imfinzi for NSCLC are as follows.

Body weight Biweekly dosage Monthly dosage
less than 30 kg (about 66 lb) 10 mg/kg* once every 2 weeks not recommended
30 kg (about 66 lb) or more 10 mg/kg† once every 2 weeks 1,500 mg once every 4 weeks

* For example, a person weighing 25 kg (about 55 lb) would receive a dose of 250 mg.
† For example, a person weighing 75 kg (about 165 lb) would receive a dose of 750 mg.

Dosage considerations

Below are some things to consider about Imfinzi’s dosage.

  • Missing a dose. If you miss an appointment to receive your Imfinzi infusion, call your healthcare professional to reschedule. Try these medication reminder options to help avoid missing doses. You could also set an alarm, use a timer, or download a reminder app on your phone.
  • Length of treatment. Doctors may prescribe Imfinzi as a long-term treatment. You may take it long term if you and your doctor feel it’s safe and effective for your condition. For SCLC, your doctor will advise on the length of time you’ll receive Imfinzi infusions. For NSCLC, you may receive Imfinzi infusions for up to 1 year.

Imfinzi: Questions you may have

Here are some common questions about Imfinzi and brief answers to them. If you’d like to know more about these topics, ask your doctor.

Do doctors prescribe Imfinzi for bladder cancer?

Imfinzi is no longer approved to treat bladder cancer.

In the past, Imfinzi had received accelerated approval from the Food and Drug Administration (FDA) to treat bladder cancer in certain situations. (Accelerated approval means that Imfinzi was made available to the public for this use before its clinical studies were completed. The FDA sometimes allows this for medications used to treat conditions without many treatment options, such as bladder cancer.)

However, the results of a later clinical study showed Imfinzi was not effective for bladder cancer. As a result, Imfinzi’s manufacturer and the FDA removed bladder cancer as an approved use of the drug. For this reason, doctors aren’t likely to prescribe Imfinzi to treat bladder cancer.

If you have bladder cancer, talk with your doctor about other treatment options for your condition.

How long can you take Imfinzi?

How long you’ll take Imfinzi depends on the condition you’re using the drug to treat. It also depends on how effective the drug is and the side effects you may have.

For small cell lung cancer, your doctor will prescribe Imfinzi for as long as it’s effective for your condition. Or they’ll prescribe it for as long as you don’t have serious side effects.

For non-small cell lung cancer, your doctor will prescribe Imfinzi for a maximum of 1 year. They may prescribe the drug for a shorter time if it’s not effective for your condition or if you have serious side effects.

To learn more about how long you’ll take Imfinzi, talk with your doctor.

Imfinzi: How it is administered

Your doctor will recommend how Imfinzi will be administered to you. It’s important to receive the drug exactly as your doctor instructs.

Imfinzi is given as an IV infusion by a healthcare professional. They’ll give you the drug as a slow injection into your vein. Each Imfinzi infusion lasts about 1 hour.

Imfinzi infusions may be given in a clinic, hospital, or infusion center. You won’t give yourself Imfinzi infusions.

Questions about receiving Imfinzi

Here’s a list of common questions related to receiving Imfinzi.

  • When should I receive Imfinzi? You’ll receive Imfinzi infusions every 2 weeks, every 3 weeks, or monthly. Your doctor can recommend the dosing schedule that’s right for you. Try these medication reminder options to help avoid missing doses of Imfinzi. You could also set an alarm, use a timer, or download a reminder app on your phone.
  • Do I need to receive Imfinzi with food? You can receive Imfinzi infusions with or without having eaten food.
  • Is there a best time of day to receive Imfinzi? No, there isn’t a best time of day to receive Imfinzi. You can receive an infusion any time of day.

Imfinzi: Consuming alcohol during treatment

There isn’t a known interaction between alcohol and Imfinzi.

However, keep in mind that drinking alcohol could worsen certain side effects of Imfinzi. Examples include fatigue and digestive problems, such as nausea and vomiting.

If you drink alcohol, your doctor can advise you on the amount that’s safe to consume during treatment.

Imfinzi: Interactions

Imfinzi isn’t known to interact with other medications, supplements, or foods. However, this doesn’t mean interactions can’t occur with Imfinzi.

Different interactions can cause different effects. Some interactions can interfere with a drug’s effectiveness. Others can increase a drug’s side effects or cause them to be severe.

Before you start Imfinzi, be sure to tell your doctor about any medications, herbs, vitamins, or supplements you take. They can check for any possible interactions between these products and Imfinzi.

For information about drug-condition interactions, see the “Imfinzi: Precautions” section below.

Imfinzi: Using while pregnant

Imfinzi is not safe to use while pregnant. The way Imfinzi works in the body could cause harm to a fetus if the drug is used during pregnancy.

In addition, animal studies have shown harm to offspring born to animals given the drug during pregnancy. However, keep in mind that animal studies will not always predict what happens with humans.

To be safe, doctors typically will not prescribe Imfinzi during pregnancy. If you’re able to become pregnant, your doctor will give you a pregnancy test to rule out pregnancy before Imfinzi treatment is started. And they’ll also recommend that you use birth control during treatment. See the “Imfinzi: Birth control needs” section below for details.

If you’re pregnant or planning to become pregnant, talk with your doctor. They’ll likely prescribe a treatment other than Imfinzi for your condition.

Imfinzi: Birth control needs

It’s not safe to use Imfinzi during pregnancy. Talk with your doctor about your birth control needs with Imfinzi if you’re sexually active and you or your partner can become pregnant. Your doctor can recommend an effective form of birth control to use with this medication.

If you’d like to learn more about taking Imfinzi during pregnancy, see the “Imfinzi: Using while pregnant” section above.

Note: Sex and gender exist on spectrums. In this article, use of the terms “male” and “female” refers to sex assigned at birth.

For females taking Imfinzi

If you’re a female who’s able to become pregnant, your doctor can recommend an effective form of birth control to use with Imfinzi. They’ll likely recommend you use birth control during Imfinzi treatment and for at least 3 months after your last dose of the drug.

For males taking Imfinzi

The manufacturer of Imfinzi hasn’t supplied birth control recommendations for males using Imfinzi.

If you’re a male using Imfinzi and you’re sexually active with a partner who’s able to become pregnant, talk with your doctor. They can advise whether you’ll need to use birth control while using Imfinzi.

Imfinzi: Using while breastfeeding

It’s not known whether Imfinzi passes into breast milk. It’s not known if the drug could cause side effects in a breastfed child.

To be safe, your doctor will likely recommend that you do not use Imfinzi while breastfeeding. And they may instruct you to avoid breastfeeding for at least 3 months after your last dose of the drug.

If you’re breastfeeding or planning to breastfeed, talk with your doctor before using Imfinzi. They can advise you on healthy ways to feed your child.

Imfinzi: Precautions

Tell your doctor about your health history before starting treatment with Imfinzi. Your doctor may not recommend this medication if you have certain factors affecting your health or specific medical conditions. These situations are considered drug-condition interactions.

These factors and conditions include those listed below.

  • Nervous system problems. Before using Imfinzi, tell your doctor if you have problems with your nervous system. Examples include Guillain-Barré syndrome and myasthenia gravis. Imfinzi may cause your immune system to become overactive, which could cause inflammation in certain areas of your body. And inflammation could worsen any nervous system problems you may have. Your doctor can recommend whether Imfinzi is the right treatment for your condition.
  • Immune system problems. Imfinzi may cause your immune system to become overactive. This could lead to side effects that cause inflammation in certain areas of your body. This inflammation could worsen any immune system problems you may have. Before using Imfinzi, tell your doctor if you have any immune system problems. Examples include Crohn’s disease, lupus, and ulcerative colitis. If you have these conditions, your doctor can recommend whether Imfinzi is the right treatment option for you.
  • Have had a stem cell transplant in the past. In some cases, Imfinzi may cause life threatening reactions in people who’ve had a stem cell transplant in the past. If you’ve had a stem cell transplant or plan to have one, your doctor will advise you on whether it’s safe to use Imfinzi.
  • Have had an organ transplant in the past. Before using Imfinzi, tell your doctor if you’ve had an organ transplant. Imfinzi may cause your immune system to become overactive, which could cause your body to reject the transplanted organ. Your doctor can recommend whether Imfinzi is the right treatment option for your condition.
  • Have had radiation treatment to your chest in the past. Imfinzi may cause pneumonitis (inflammation in the lungs) as a side effect. You may have a higher risk for this side effect if you’ve had radiation treatment to your chest. If you’ve had this treatment in the past, your doctor can recommend whether it’s safe to use Imfinzi.
  • Allergic reaction. Your doctor will likely not prescribe Imfinzi if you’ve had an allergic reaction to it or any of its ingredients. To find out about other treatment options, talk with your doctor.
  • Pregnancy. It’s not safe to receive Imfinzi while pregnant. If you’d like additional information about taking Imfinzi while pregnant, view the “Imfinzi: Using while pregnant” section above.
  • Breastfeeding. It’s not known whether Imfinzi passes into breast milk. If you’d like additional information about taking Imfinzi while breastfeeding, view the “Imfinzi: Using while breastfeeding” section above.

To learn more about effects of Imfinzi that could be harmful, see the “Imfinzi: Side effects” section above.

Imfinzi: Questions for your doctor

If you have questions about Imfinzi, talk with your doctor. They can help advise you on whether Imfinzi could be a good treatment option for you.

Here’s a list of questions you may want to ask your doctor:

  • How many Imfinzi treatments will I need?
  • What tests can be used to check whether Imfinzi is working to treat my condition?
  • Am I able to get vaccinated while using Imfinzi?

Your doctor may also tell you about other treatment options for your condition. You may find this article helpful in learning about alternative drugs. And view our selection of videos on lung cancer.

Disclaimer: Healthgrades 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.

Medical Reviewer: Dena Westphalen, Pharm.D.
Last Review Date: 2022 Aug 1
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.