What to Know About Imfinzi for Biliary Tract Cancer

Medically Reviewed by Simi Burn, PharmD on October 21, 2024
8 min read

If you or a loved one has gallbladder or bile duct cancer, you may be interested in learning more about treatments for it. For a long time, the standard treatment options for this cancer type were limited to surgery, chemotherapy, and radiation. Now, a newer option is available: an immunotherapy medicine called Imfinzi (durvalumab). Immunotherapy medicines work by helping your immune system find and attack cancer cells.

The FDA approved Imfinzi in 2017. It is commonly used to treat biliary tract cancer that has spread to nearby tissues or other areas of the body. 

Biliary tract cancer refers to various types of cancer that start in the gallbladder or bile ducts. The gallbladder is a small organ under the liver that stores bile. Gallbladder cancer is usually found after it has spread. Bile ducts are tubes that carry bile, a fluid made by the liver that helps digest food. Bile duct cancer is also known as cholangiocarcinoma.

Imfinzi is also FDA-approved to treat various other cancers, including certain types of early and advanced lung cancer. It is also approved to treat liver cancer that cannot be removed by surgery as well as a certain type of endometrial cancer that has spread or come back. 

Imfinzi may also be used for other conditions as determined by your health care provider. This article focuses on Imfinzi for biliary tract cancer. Below are common questions and answers about Imfinzi’s role in treating biliary tract cancer.

Imfinzi is an FDA-approved treatment for biliary tract cancer in combination with two chemotherapy medicines: cisplatin and gemcitabine. Imfinzi is specifically approved for adults with biliary tract cancer that has spread to nearby tissues (locally advanced) or other areas of the body (metastatic).

If you have gallbladder or bile duct cancer, an oncologist (a cancer specialist) can help decide if Imfinzi is a good treatment option for you.  

Imfinzi is a type of immunotherapy known as a checkpoint inhibitor. It helps your immune system fight cancer by blocking a checkpoint protein called PD-L1. Normally, checkpoint proteins on cells let your immune system know which cells to ignore and which cells to attack. Some types of cancer cells make large amounts of PD-L1 to try to hide from your immune cells (T-cells), preventing them from attacking the cancer. 

When Imfinzi blocks PD-L1, it stops this "hiding" process, which allows your T cells to find and attack the cancer cells. This boosts your body's natural immune response to cancer. By blocking PD-L1, Imfinzi can increase T cell activity, help shrink tumors, and slow down cancer growth. This may help some people live longer without their cancer getting worse.

Imfinzi is given by a health care professional in a hospital or clinic. It is given as an infusion into a vein (intravenously). It usually takes about an hour to receive your dose of Imfinzi. 

To treat biliary tract cancer, Imfinzi is given once every 3 or 4 weeks. Your health care team will check your body weight to determine your exact dose. They can also give you more details about your treatment schedule. 

The length of Imfinzi treatment depends on several things, such as how well the medicine works for you and how it affects you.

For treatment of gallbladder or bile duct cancer, you will likely receive Imfinzi once every 3 weeks along with certain chemotherapy medicines for up to eight cycles. Then you will receive Imfinzi by itself once every 4 weeks. You may continue taking Imfinzi for as long as the medicine is still effective and safe for you. 

Some people may have to stop Imfinzi treatment earlier than planned if their cancer gets worse or if they have certain side effects that make it unsafe to continue. 

If you have side effects from Imfinzi, your health care provider may give your dose more slowly than usual, meaning the infusion will take longer than an hour. Or they may pause your treatment until the side effects ease or go away. In some cases, if side effects are severe or cannot be managed, they may stop your Imfinzi treatment completely. 

A clinical study called TOPAZ-1 was done to test how well Imfinzi works for treating biliary tract cancer. The study also looked at the safety of Imfinzi by collecting information about side effects. 

Everyone who participated in this study had to meet certain requirements, such as being an adult and having a confirmed case of bile duct cancer or gallbladder cancer that had spread to nearby tissues (locally advanced) or other areas of the body (metastatic). Some people had received other treatments in the past, such as surgery, but their cancer came back. But for some people, this study was their first treatment since they found out they had cancer.

A total of 685 adults enrolled in the study. The participants ranged from 20 to 84, and about half were male. The study included people of different racial backgrounds: Asian (56%), White (37%), Black or African American (2%), American Indian or Alaskan Native (0.1%), and others (4%). More than half of the participants were from Asia, and the rest were from around the world. 

Participants were randomly assigned to one of two groups. 

  • The Imfinzi group received Imfinzi plus standard chemotherapy (cisplatin and gemcitabine) for up to eight cycles, then received Imfinzi once every 4 weeks. 
  • The placebo group received a placebo plus standard chemotherapy (cisplatin and gemcitabine) for up to eight cycles, then received a placebo once every four weeks. (A placebo is a treatment that contains no medicine.) 

During the study, no one knew which treatments they were getting. People continued Imfinzi or placebo for as long as possible, until their cancer got worse or if they developed side effects that were too severe to continue.

The main goal of the study was to test how well Imfinzi worked for biliary tract cancer. To measure this, the researchers kept track of how long people lived to see if Imfinzi helped people live longer than standard chemotherapy alone.

The results of the TOPAZ-1 study showed that Imfinzi was an effective treatment for biliary tract cancer. On average, people who received Imfinzi plus chemotherapy lived slightly longer than people who received a placebo plus chemotherapy. 

  • Overall survival of the Imfinzi/chemotherapy group was 12.8 months.
  • Overall survival of the placebo/chemotherapy group was 11.5 months.

Your results may be different from what was seen in clinical studies.

According to treatment guidelines from the National Comprehensive Cancer Network (NCCN), the preferred treatment option for people with biliary tract cancer that has spread and cannot be removed by surgery is Imfinzi (durvalumab) plus cisplatin and gemcitabine. NCCN describes a preferred treatment as “one proven to have a better result.” 

Your health care provider can help decide the right treatment option for you. 

Immunotherapy medicines like Imfinzi can help your immune system find and attack cancer cells. But they can also cause your immune system to attack healthy parts of your body. This can lead to inflammation in different organs and tissues, which can become severe or even life-threatening. These reactions can happen at any time during treatment with Imfinzi or even after you stop it.

While these side effects can be serious, early detection and management can help prevent them from getting worse. Keep track of any new or worsening symptoms. If something feels off, do not wait — contact your health care provider right away. While not a complete list, here are some areas of the body that may become inflamed and the symptoms to watch for.

  • Lungs. If you develop a persistent cough, shortness of breath, or chest pain, these could be signs of lung inflammation.
  • Digestive tract. Diarrhea, black or bloody stools, and stomach pain could be signs of inflamed intestines.
  • Liver. Symptoms like yellowing skin or eyes, severe nausea, or pain in your upper right abdomen may be symptoms of liver inflammation.
  • Hormone glands. Hormone changes may cause headaches, unusual tiredness, or changes in weight or mood.
  • Kidneys. Decreased urine, blood in your urine, or swelling in your ankles could signal kidney problems.
  • Skin. Watch for rashes, itching, blistering, or peeling skin.
  • Pancreas. Severe stomach pain, vomiting, or dark urine may be signs of pancreas inflammation.

Your health care provider will also monitor you closely during treatment. Make sure to keep all appointments and get any recommended tests to catch side effects early. If side effects from Imfinzi become severe, your treatment may be paused or stopped altogether. 

The safety of Imfinzi in combination with cisplatin and gemcitabine was evaluated in a clinical study called TOPAZ-1. Based on the results, the FDA approved this specific combination of medicines to treat biliary tract cancer that has spread. More than 20% of people in this study had the following common side effects:

  • Tiredness
  • Nausea
  • Constipation
  • Decreased appetite
  • Pain in the abdomen
  • Rash

Serious side effects were also common. Nearly half (47%) of people in the study who received Imfinzi plus cisplatin and gemcitabine had at least one serious side effect. The most common serious side effects were inflamed bile ducts (cholangitis), fever, anemia (low red blood cells), sepsis (blood infection), and kidney problems. While less common, serious side effects can lead to death in some cases.  

For your safety, your health care provider will monitor you closely during treatment. Tell them if you have new or unusual symptoms. Make sure to keep all appointments and get any recommended tests to watch for side effects. If side effects from Imfinzi/cisplatin/gemcitabine become severe, your health care provider may pause your treatment or stop it completely.

If you can become pregnant, your health care provider may give you a pregnancy test before you start treatment with Imfinzi. They need to make sure you are not pregnant because Imfinzi may cause harm to a fetus. To prevent pregnancy, it is recommended to use birth control during Imfinzi treatment and for three months after your last dose. 

A cost assistance program is available from the manufacturer of Imfinzi, AstraZeneca. If you qualify, this program may reduce the amount you pay. Whether you qualify to enroll may depend on what type of insurance you have or if you are uninsured. 

Visit this website for more information about Imfinzi costs and copay savings. You can also call the manufacturer at 844-275-2360 to connect with a representative for financial support information and other resources.