What to Know About Imfinzi (Durvalumab)

Immunotherapy Drug to Treat Some Forms of Lung and Bladder Cancer.

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One of a class of drugs called checkpoint inhibitors, Imfinzi (generically known as durvalumab) is used to take on certain forms of lung and bladder cancer that have started to spread.

Prescribed either as a standalone treatment or alongside other drugs, this drug works by binding and blocking the activity of programmed death ligand 1 (PD-L1) proteins, thereby helping the immune system attack cancer cells. It’s administered using intravenous (IV) injection in the hospital under the care of oncology doctors and dedicated staff.

African nurse preparing IV drip - stock photo
 Jose Luis Pelaez Inc./Getty Images


Imfinzi is approved by the Food and Drug Administration (FDA) to take on several serious forms of cancer, including bladder cancer, non-small cell lung cancer (NSCLC), and extensive-state small cell lung cancer (ES-SCLC).

Bladder Cancer

This drug was initially approved to take on bladder cancer (urothelial carcinoma), in both locally advanced and metastatic stages, the latter of which means that the cancer is starting to spread throughout the body. It’s typically indicated after chemotherapy or other approaches haven’t yielded desired results.

Non-Small Cell Lung Cancer

A term for a group of lung cancers that act similarly, NSCLCs include squamous cell carcinoma and adenocarcinoma, among others. In these cases, Imfinzi is usually administered only after disease progression has not been observed with chemotherapy or radiation treatment and is reserved for when this cancer is at stage III or higher.

Extensive-Stage Small Cell Lung Cancer

ES-SCLC refers to a stage of lung cancer in which cancerous cells have spread throughout the lungs, as in when it has moved from one lung to the other, to lymph nodes, or other parts of the body.

Imfinzi is considered a first-line treatment for ES-SCLC when taken alongside the chemotherapy drugs, such as Toposar or Etopophos (etoposide), Paraplatin (carboplatin), and Cisplatin.

Before Taking

Proper diagnosis is absolutely essential prior to administration of Imfinzi, and a number of other factors need to be considered prior to its use. As noted above, this drug may be the first-line of treatment for ES-SCLC, but it usually isn’t for bladder cancer or NSCLC.

There are some slight differences between the way bladder cancers and lung cancers are diagnosed. Here’s a quick breakdown:

Bladder Cancer Diagnosis

The first step in diagnosis is a physical examination and a review of medical history. If the healthcare provider suspects a problem, the next step involves analysis of the urine for the presence of blood and/or cancer cells.

In addition, cystoscopy, an approach in which a specialized tube with a camera (a cystoscope) is inserted into the urethra to scan for any tumor growth. Following that, biopsy is performed; this is when a sample from any problematic tissues or cells is then taken and analyzed.

Imaging approaches such as X-ray, magnetic resonance imaging (MRI), or computer tomography (CT) are employed to get a full sense of cancer spread.

Lung Cancer Diagnosis

Diagnosis of lung cancers, in many ways, follows a similar progression. Following initial examination, if cancer is suspected, the healthcare provider may call for a biopsy of lung tissue and employ imaging to get a sense of disease state.

The biopsy will confirm the presence of cancer. Imaging—either chest X-ray, CT scan, MRI, ultrasound, or positron emission tomography (PET)—allows healthcare providers to see the size and scope of tumors and cancerous tissues.

Throughout this process, be sure to communicate openly with your medical team and don’t hesitate to ask any questions or concerns.

Precautions and Contraindications

The effect on the body of taking Imfinzi can be quite dramatic, so healthcare providers need to be sure it’s safe for patients to take it. What conditions might preclude prescription of this drug? Here’s a quick breakdown:

  • Pregnancy: Evidence from animal studies suggests that this drug may be passed from expectant mother to the fetus, potentially causing harm. As such, pregnancy may cause the healthcare provider to consider alternatives, and women undergoing treatment are advised not to get pregnant during this time and for three months afterward.
  • Age: The safety of this drug has not been established for children. The safety for people above age 70 is currently investigated in a clinical study.
  • Breastfeeding: People who are breastfeeding will be advised not to do so during the course of treatment.
  • Liver problems: The safety of the drug in patients with liver problems has not been studied. A history of liver problems such as cirrhosis or hepatitis may prompt healthcare providers to consider other approaches.
  • Thyroid disorders: There’s significant evidence that taking Imfinzi can have a harmful effect on the thyroid. Before undergoing treatment, the health of this organ is assessed, and existing problems may cause the healthcare provider to reconsider going ahead.
  • Type 1 diabetes: This therapy has also been linked with the development and progression of type 1 diabetes. Healthcare providers will test for this condition, monitoring it if treatment goes ahead. Some cases of this disease may call for the healthcare provider to reconsider their approach.
  • Kidney problems: The safety of the drug in patients with Kidney problems has not been studied. Before treatment begins, the healthcare provider will assess kidney health to determine whether patients are a good fit for therapy. Monitoring kidney health is an essential component throughout treatment. 
  • Allergic reaction: As Imfinzi is administered via IV, the medical team will monitor for allergic responses, clinically referred to as “infusion-related reactions.” Some of these can be quite severe and even fatal, leading the healthcare provider to either modify or discontinue this therapy.

Currently there are very few interactions of Imfinzi with other drugs (details below). It is always a good idea to inform your healthcare provider about all medications, supplements, and vitamins that you currently take.

Other Checkpoint Inhibitors

Imfinzi is just one in a class of drugs that work similarly called checkpoint inhibitors. Others of this type in current use include:


Imfinzi is administered via IV in the hospital and does not come in a pill form. This administration takes about 60 minutes per session, and these sessions occur every two to four weeks.

The specific amounts recommended for therapeutic vary based on the condition being treated as well as whether the drug is administered on its own or alongside chemotherapy. Here’s a quick breakdown:

  • Bladder cancer: It’s recommended that people with urothelial carcinoma receive 10 milligrams (mg) per kilogram (kg) of bodyweight once every two weeks. Treatment should cease if adverse effects become too difficult or if the cancer continues to spread.
  • NSCLC: As with bladder cancer, this form of lung cancer is treated with 10 mg of active dose for every kg of weight. These are to be administered once every two weeks until toxicity in the body is overwhelming or the cancer is observed to continue spreading for an absolute maximum of 12 months. 
  • ES-SCLC: For this cancer, if Imfinzi is recommended as an adjunct, it will typically be administered prior to chemotherapy. In these cases, doses of 1,500 mg every three weeks for a maximum of four cycles are indicated. Following that, or if this drug is given as a standalone treatment, the same 1,500 mg dose is delivered every four weeks.

Keep in mind that specific dosages for your case are up to your healthcare provider; these amounts are FDA recommendations, not prescriptions.


Aside from natural variations based on weight, dosage of Imfinzi is relatively consistent. That said, modifications to the course of administration do become necessary if there are adverse reactions. Here’s a quick summary of what might happen in the face of these:

  • Pneumonitis: This inflammation of the lungs can be a side-effect of treatment, and severity is described as being anywhere from grade one (the least severe) to grade four. If you have grade two, use of Imfinzi should be temporarily halted until the condition improves, and steroid drugs will be prescribed to take on the issue. Grades three and four prompt an immediate and permanent discontinuation of treatment.
  • Hepatitis: Due to its effect on the immune system, use of Imfinzi has also been linked to the onset of hepatitis (an inflammation of the liver). Throughout treatment, healthcare providers monitor liver health, withholding dosage and prescribing corticosteroid drugs like prednisone until matters resolve in more mild cases. For more severe cases, treatments should stop indefinitely. 
  • Colitis/diarrhea: As with other conditions, the severity of colitis (an inflammation of the colon) is measured as going from grade one (the mildest form) to grade four. In grade two cases, dosage of Imfinzi is withheld until the condition improves, and other drugs, like prednisone, may be indicated. For more severe colitis of grades three or four, treatment needs to be stopped. 
  • Hyperthyroidism: Overactive thyroid, known as hyperthyroidism, can also occur in the course of treatment. If detected, treatment will need to be paused until the condition resolves.
  • Adrenal insufficiency: Also known as Addison’s disease, adrenal insufficiency is when the body’s adrenal glands don’t produce enough of the hormone, cortisol. This is a potential adverse reaction to treatment itself; dosage of Imfinzi should be withheld until this condition improves.
  • Type 1 diabetes: Due to its activity on the pancreas, this therapy can lead to or act upon existing cases of type 1 diabetes, which is when your body doesn’t produce enough of the digestive enzyme, insulin. As with other diseases, progression is rated on a scale from one (the mildest form) to four (the most severe). This is monitored throughout, and if the condition progresses to grade two to four, Imfinzi treatment is paused until levels to return to normal.
  • Nephritis: Another condition that can arise during the course of treatment is nephritis, which is an inflammation in the kidneys. More mild cases indicate prescription of additional drugs and pausing treatments until there’s improvement. In more severe cases, Imfinzi administration is stopped altogether.
  • Rash/dermatitis: Another side effect seen with this treatment, more mild cases of rash (grade two for longer than one week, or grade three) prompt cessation of therapy until it improves or resolves. For more severe cases, application of the drug should be discontinued.

As mentioned above, adverse reactions during the course of treatment may also prompt it to be discontinued, which is why you’re carefully monitored during every application of Imfinzi. In addition, since this drug can only be administered via IV, patients don’t need to worry about storage or disposal.

Side Effects

Like all cancer drugs, Imfinzi is associated with a wide range of side-effects due to its effect on the immune system. That said, these are usually reversible and will go away after treatment has stopped.

Whereas some are more common and expected during the course of treatment, others are much more dangerous and constitute medical emergencies. It’s essential that you keep track of how you’re feeling, and don’t hesitate to seek help if you’re feeling sick or off.


The more frequently seen side-effects seen with Imfinzi, while largely manageable, can be signs of more dangerous conditions, so healthcare providers monitoring for them throughout. These include:

  • Fatigue
  • Infection
  • Muscle and bone pain
  • Constipation
  • Decreased appetite
  • Rash
  • Nausea
  • Swelling
  • Urinary tract infection
  • Abdominal infection
  • Fever
  • Colitis
  • Diarrhea
  • Decreased sodium level
  • Lower white cell count 


Alongside the more common side-effects, some adverse reactions to Imfinzi occur when the body’s immune system starts targeting healthy cells. These are more problematic and often require immediate medical attention as well as immediate cessation of the therapy. Here’s a quick breakdown:

  • Pneumonitis: As noted above, pneumonitis is an inflammation of the kidney that may arise during treatment. Symptoms include shortness of breath, cough (especially if it doesn’t improve and gets worse), and chest pains.
  • Hepatitis: This liver disorder can cause yellowing of eyes or skin, severe nausea and/or vomiting, pain on the right side of the stomach, dark or brown-colored urine, as well as easier bleeding or bruising.
  • Hypothyroidism: Underactive thyroid can also occur during Imfinzi treatment. Initiate thyroid replacement therapy as clinically indicated.If hypothyroidism worsens, Imfinzi treatment is paused until levels to return to normal.
  • Moderate to severe colitis: These intestinal issues lead to diarrhea, blood in the stool, and severe stomach pain.
  • Gland problems: As discussed, use of Imfinzi can also affect the pancreas, thyroid, and adrenal glands. Signs and symptoms of these types of problems vary a great deal and include rapid or slow heartbeat, leg swelling, excessive sweating, fatigue, sudden weight fluctuation, increased thirst or appetite, high blood sugar, hair loss, irritability and cognitive effects, constipation, deepening of the voice, low or high blood pressure, frequent urination, and stomach pain.
  • Kidney problems: Adverse effects of Imfinzi on the kidney lead to less frequent urination, blood in the urine, ankle swelling, and loss of appetite.
  • Other severe effects: A range of other organ systems can be affected by this drug. These can lead to neurological symptoms, such as headache, confusion, and change in balance. Other troubling symptoms include severe muscle weakness and pain, chest pain and tightness, trouble breathing, skin rashes, irregular heartbeat, and flu-like symptoms.

Immediately seek help if you have a fever of above 100.4 F, shortness of breath, excessive cough, as well as confusion and imbalance. If other symptoms are problematic, be sure to let your healthcare provider know as soon as possible; good communication is essential for positive outcomes.

Warnings and Interactions

As with any pharmaceutical drug, Imfinzi activity can also be affected by other drugs and substances you’re taking. In particular, the following are known to interact with this drug:

  • Kepivance (palifermin): A drug prescribed to help with chemotherapy, Kepivance should not be administered within the 24 hours before or after Imfinzi treatment.
  • Depen Titratabs/Cuprimine (penicillamine): Indicated to take on toxicity due to elevated copper levels in the blood, Depen Titratabs, also known as Cuprimine, should not be used throughout the course of treatment.
  • Aplical/Mantoux/PPD (tuberculin purified protein derivative): Immunosuppressive drugs like Imfinzi may also be hampered by tuberculin purified protein derivatives, which are used to diagnose for tuberculosis. As such, use of these should wait until six weeks after treatment.

Keep in mind that other substances you’re consuming may also interact with Imfinzi. When meeting with your healthcare provider for evaluation, have a list handy of all the medications you’re taking as well as any other herbs or supplements you’re taking.

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7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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