Atezolizumab (Tecentriq) is an immunotherapy that was granted accelerated approval by the Food and Drug Administration in March 2019 to treat metastatic triple-negative breast cancer that expresses the PD-L1 protein. Genentech, the manufacturer, voluntarily withdrew approval in 2021 because follow-up research failed to confirm the initial promising results that prompted the accelerated approval. These final results showed that combining atezolizumab with paclitaxel did not offer a survival advantage over paclitaxel alone. It had been approved for use with the chemotherapy medicine nab-paclitaxel (Abraxane) as a first-line treatment.

The withdrawal applies only to people in the U.S. – atezolizumab remains in use in other parts of the world – and it did not affect the medication’s use in other types of cancer, such as bladder, liver, and lung cancer.

Atezolizumab is no longer prescribed as a new first treatment for metastatic triple-negative breast cancer. While this is disappointing, there are other immune checkpoint inhibitors, such as pembrolizumab (Keytruda), that are FDA approved to treat metastatic breast cancer, as well as other options for triple-negative disease.

If you were prescribed atezolizumab between 2019 and 2021 and had a good response, however, your doctor may suggest you remain on the medication. This page will help you better understand atezolizumab If you continue to take it.


How atezolizumab works

Atezolizumab is a type of immunotherapy known as an immune checkpoint inhibitor. The protein PD-L1 is an immune “checkpoint,” meaning that it prevents the immune system from destroying any cells that carry this protein. When breast cancer cells express this protein, they can lead the immune system to believe they are normal, healthy cells—and this keeps the immune system from destroying them.

Atezolizumab was designed to block PD-L1 so that the immune system’s T-cells would then know to attack the cancer cells. Those who take atezolizumab had the immune cells tested in and around the breast cancer to see whether they expressed PD-L1 and would be more likely to respond to atezolizumab.


Who receives atezolizumab

Although atezolizumab is no longer approved in the U.S. for metastatic triple-negative breast cancer that expresses the PD-L1 protein, those who were taking atezolizumab before it was withdrawn may be able to stay on the treatment.

The drug’s manufacturer may provide financial assistance if the cancer is responding well but your insurance company will no longer cover atezolizumab. Reach out to the Genentech Patient Resource Center at (877) 436-3683 to answer questions about your health insurance coverage and possible financial assistance.

In other cases, care teams have decided to switch people to another immune checkpoint inhibitor, pembrolizumab. If you find yourself in this situation, talk to your healthcare team to see what they recommend.


How atezolizumab is given

Atezolizumab is given by vein at a cancer treatment center. The first treatment was given over the course of an hour, and follow-up infusions are given every 3 weeks and take 30 minutes.


Side effects and things to remember

The side effects of this treatment combination include nausea, cough, low white blood cell counts, and hypothyroidism, a condition where your body does not produce enough thyroid hormones. People on this regimen are more likely to have grade 3 or 4, or very severe, neuropathy (tingling or numbness in the hands and feet) than people taking nab-paclitaxel alone. Side effects that are grade 3 or 4 interfere with daily life and require medical attention.

Atezolizumab, like other immunotherapies, is linked to immune-related side effects that can take different forms, including problems in the endocrine system, lungs, liver, skin, or intestines, or reactions to the infusion of the medicine. If you’re still taking atezolizumab, your healthcare team should continue to advise you about watching for these problems and what symptoms you should report right away.


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Reviewed and updated: August 5, 2022

Reviewed by: Douglas Yee, MD


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