Imfinzi (durvalumab) is a brand-name drug that’s prescribed for certain types of cancer. It comes as an intravenous (IV) infusion. The dosage can vary depending on what condition the drug is used to treat.

Imfinzi may be prescribed with other drugs to treat the following types of cancer:

It may also be prescribed on its own for NSCLC which has already been treated with chemotherapy and radiation.

Imfinzi is a biologic and belongs to a drug class called PD-L1 inhibitors. Imfinzi isn’t available in a biosimilar version.

Keep reading for specific information about the dosage of Imfinzi, including its strength and how you’ll receive the medication. For a comprehensive look at Imfinzi, see this article.

Note: This article describes typical dosages for Imfinzi provided by the drug’s manufacturer. However, your doctor will prescribe the Imfinzi dosage that’s right for you.

Read below for recommended dosages of Imfinzi and other details about the drug.

Imfinzi form

Imfinzi comes as a solution that’s given as an intravenous (IV) infusion. It’s always given by a healthcare professional in their office or clinic.

Imfinzi strength

Imfinzi comes in one strength of 50 milligrams (mg) per milliliter (mL) of solution.

It’s available in single-dose vials containing 2.4 mL or 10 mL of solution.

Typical dosages

The following information describes dosages that are commonly used in adults.

Dosage for metastatic non-small cell lung cancer

Doctors may prescribe Imfinzi to treat NSCLC that has spread to other body parts. For this use, the drug is typically given with other cancer treatments.

If your doctor prescribes Imfinzi for your metastatic NSCLC, your starting dose will depend on your weight in kilograms (kg). One kg is 2.2 pounds (lb).

If you weigh less than 30 kg (66 lb), the recommended dosage of Imfinzi is 20 mg per kg (mg/kg) of body weight.

If you weigh 30 kg or more, the recommended dosage of Imfinzi is 1,500 mg.

Typically, you’ll start treatment by receiving your dosage every 3 weeks with chemotherapy. After four treatment cycles, you’ll start receiving Imfinzi every 4 weeks.

For more information about your specific dosage, talk with your doctor.

Dosage for unresectable non-small cell lung cancer

Imfinzi may be prescribed to treat NSCLC that can’t be surgically removed. For this use, the drug is typically prescribed alone.

If your doctor prescribes Imfinzi for your NSCLC, your starting dose will depend on your weight.

If you weigh less than 30 kg, the recommended dose of Imfinzi is 10 mg/kg of body weight. You’ll typically receive this dose every 2 weeks.

If you weigh more than 30 kg, your dosage of Imfinzi may vary. You could receive 10 mg/kg of body weight every 2 weeks or 1,500 mg every 4 weeks. Your doctor will prescribe the best dosage for your condition.

For more information about your specific dosage, talk with your doctor.

Dosage for small-cell lung cancer

Imfinzi may be used to treat extensive-stage SCLC. This is SCLC that has spread to other body parts. For this condition, Imfinzi is typically prescribed with other cancer treatments.

If your doctor prescribes Imfinzi for your SCLC, your starting dose will depend on your weight.

If you weigh less than 30 kg, your typical starting dose will be 20 mg/kg of body weight. You’ll likely receive this every 3 weeks with chemotherapy.

After four treatment cycles, you’ll start receiving Imfinzi on its own. The dosage for Imfinzi after chemotherapy is 10 mg/kg of body weight, given every 2 weeks.

If you weigh more than 30 kg, the recommended starting dosage of Imfinzi is 1,500 mg. You’ll receive this dosage every 3 weeks for the duration of your chemotherapy treatment. After that, you’ll start receiving Imfinzi on its own every 4 weeks.

For more information about your specific dosage, talk with your doctor.

Dosage for biliary tract cancer

Doctors may prescribe Imfinzi to treat metastatic biliary tract cancer. This is cancer that has spread from the bile ducts to other body parts. For this condition, Imfinzi is usually given with chemotherapy.

If your doctor prescribes Imfinzi for this type of cancer, your starting dose will depend on your weight.

If you weigh less than 30 kg, the recommended starting dose is 20 mg/kg of body weight. You’ll receive this dose every 3 weeks with chemotherapy. After you finish chemotherapy, you’ll start receiving Imfinzi on its own every 4 weeks.

If you weigh more than 30 kg, the recommended dosage of Imfinzi is 1,500 mg. You’ll start by receiving this dose every 3 weeks with chemotherapy. After you finish chemotherapy, you’ll start receiving Imfinzi on its own every 4 weeks.

For more information about your specific dosage, talk with your doctor.

Dosage for hepatocellular carcinoma

Your doctor may prescribe Imfinzi to treat unresectable HCC. This is a type of liver cancer that can’t be surgically removed. For this condition, Imfinzi is typically given with other cancer treatments.

If your doctor prescribes Imfinzi for your unresectable HCC, your starting dose will depend on your weight.

If you weigh less than 30 kg, the recommended starting dose is 20 mg/kg of body weight. You’ll receive your first dose with chemotherapy. After that, your doctor will give you Imfinzi on its own every 4 weeks.

If you weigh more than 30 kg, the recommended dosage of Imfinzi is 1,500 mg. You’ll receive your first dose with chemotherapy. Then, your doctor will start giving you Imfinzi by itself every 4 weeks.

For more information about your specific dosage, talk with your doctor.

Long-term treatment

Imfinzi is meant to be used as a long-term treatment. If you and your doctor determine that Imfinzi is safe and effective for you, you’ll likely receive it long term.

Before you start receiving Imfinzi, your doctor will discuss your treatment plan with you.

The Imfinzi dosage your doctor prescribes will depend on several factors. These include:

  • your body weight
  • how your body responds to Imfinzi
  • the type and severity of the condition you’re receiving Imfinzi to treat
  • side effects you may have with Imfinzi

Other medical conditions you have can also affect your Imfinzi dosage.

Your doctor or another healthcare professional will give Imfinzi as an IV infusion. You’ll likely go to your doctor’s office, infusion center, or a hospital to receive each dose.

Imfinzi infusions take about an hour to complete. However, if you’re receiving other infusions at the same time, this appointment may take several hours.

If you have questions about how you’ll receive Imfinzi, talk with your doctor. They can let you know what to expect and how to prepare for your appointment. The manufacturer’s website also provides information about the infusion for the specific type of cancer you’re being treated for.

If you miss your appointment for an Imfinzi infusion, call your doctor’s office as soon as possible to reschedule. They’ll adjust your dosing schedule as needed.

If you need help remembering your appointments, try setting an alarm or downloading a reminder app on your phone.

Below are some frequently asked questions about Imfinzi.

How long does it take for Imfinzi to start working?

Imfinzi starts to work after your first dose. Because of how the drug works, you likely won’t feel the drug working in your body. But your doctor will monitor your condition during treatment, including ordering various tests, to check whether the drug is working to treat your cancer.

Talk with your doctor if you have questions about what to expect with Imfinzi treatment.

Is there a typical dosage range for Imfinzi?

The typical recommended dosage range for Imfinzi will depend on the specific condition the drug is prescribed to treat.

Your body weight may also determine your dosage, including how often you receive Imfinzi.

For more information about Imfinzi dosages, see the “Imfinzi dosage” section above. You can also talk with your doctor.

The dosages in this article are typical dosages provided by the drug’s manufacturer. If your doctor recommends Imfinzi for you, they’ll prescribe the dosage that’s right for you.

Besides learning about dosage, you may want other information about Imfinzi. These additional articles might be helpful:

  • More about Imfinzi: For information about other aspects of Imfinzi, refer to this article.
  • Side effects: To learn about the side effects of Imfinzi, see this article. You can also look at the Imfinzi prescribing information.
  • Drug comparison: To find out how Imfinzi compares with Tecentriq, read this article. To see how it compares with Keytruda, refer to this article.
  • Details about cancer: For details about SCLC and NSCLC, see our lung cancer hub. For more information about the other types of cancer Imfinzi may treat, see our cancer hub.

Disclaimer: Medical News Today 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.