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

Imfinzi is approved by the Food and Drug Administration (FDA) to treat the following types of cancer in adults, usually in combination with other cancer drugs or treatments:

Imfinzi is a biologic and belongs to a drug class called PD-L1 inhibitors. Imfinzi is not 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 more comprehensive information about the drug, see this overview article on Imfinzi.

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.

The following information focuses on Imfinzi’s form, strength, and typical dosages.

Imfinzi form

Imfinzi comes as a solution 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 of Imfinzi commonly used in adults. Your doctor will determine the best dosage for your needs. In some cases, doctors may adjust your dosage from those described in this article.

Note: Imfinzi dosing information for adults weighing less than 30 kilograms (kg)* has been excluded from this article. Please refer to Imfinzi’s prescribing information for details.

* For reference, 1 kg equals about 2.2 pounds (lb); 30 kg is approximately 66 lb.

Dosage for certain types of non-small cell lung cancer

Doctors may prescribe Imfinzi to treat certain types of non-small cell lung cancer (NSCLC), including unresectable NSCLC that cannot be surgically removed and metastatic NSCLC that has spread to other parts of your body. For this use, Imfinzi is typically given in combination with other cancer treatments.

The dosage typically prescribed for NSCLC is an infusion of 1,500 milligrams (mg) of Imfinzi every 3 to 4 weeks. For information about your specific dosage, talk with your doctor.

Dosage for small cell lung cancer

Imfinzi may be used to treat extensive-stage small cell lung cancer (SCLC). This is SCLC that has spread widely throughout the lung to the other lung or to other parts of the body. For this condition, Imfinzi is typically prescribed with other cancer treatments.

The typically recommended starting dosage of Imfinzi for extensive-stage SCLC is an infusion of 1,500 mg every 3 weeks. For 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 parts of your body. For this condition, Imfinzi is usually given with chemotherapy.

The recommended dosage of Imfinzi for biliary tract cancer is typically an infusion of 1,500 mg every 3 weeks, with chemotherapy. After you finish chemotherapy, you’ll typically start receiving an infusion of 1,500 mg of Imfinzi every 4 weeks as a stand-alone treatment. For more information about your specific dosage, talk with your doctor.

Dosage for hepatocellular carcinoma

Your doctor may prescribe Imfinzi to treat unresectable hepatocellular carcinoma (HCC). This is a type of liver cancer that cannot be surgically removed. For this condition, Imfinzi is typically given with other cancer treatments.

The recommended dosage of Imfinzi for unresectable HCC is 1,500 mg. You’ll receive your first dose with immunotherapy. Then, your doctor will start giving you Imfinzi by itself every 4 weeks. For more information about your specific dosage, talk with your doctor.

Dosage for endometrial cancer

Imfinzi is also prescribed for certain types of advanced or recurrent endometrial cancer. For this purpose, the recommended dosage of Imfinzi is 1,120 mg every 3 weeks, together with other cancer medications. After 6 treatment cycles, the dosage is typically changed to 1,500 mg of Imfinzi given every 4 weeks as a stand-alone treatment.

For more information about your specific Imfinzi dosage for treatment of endometrial cancer, talk with your doctor.

Long-term treatment

Imfinzi is meant to be 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 Imfinzi infusions 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.

Here 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.

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

The dosages of Imfinzi 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: