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What type of drug is Imfinzi?

Medically reviewed by Judith Stewart, BPharm. Last updated on Feb 25, 2021.

Official Answer


Imfinzi (durvalumab) is a programmed death receptor-1 (PD-1) blocking antibody (also called an immune checkpoint inhibitor). It is used for the treatment of non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC).

What are immune checkpoints?

Immune checkpoints such as PD-1 are part of the immune system and their function is to prevent healthy cells from being destroyed when a strong immune response is triggered in the body.

Immune checkpoints are activated when proteins on the surface of T-cells recognize and bind to partner proteins on other cells (such as cancer cells) sending an “off” signal to the T-cells. This prevents the immune system from destroying the cancer cells. When the checkpoint proteins are blocked from binding with their partner proteins, the "off" signal can't be sent, and the T-cells can then kill the cancer cells.

How does Imfinzi work?

Imfinzi is a monoclonal antibody that binds to programmed cell death ligand-1 (PD-L1)
and blocks it from binding with the programmed death receptor-1 (PD-1). Blocking this binding boosts the body's immune system response against the cancer cells.

What types of cancer is Imfinzi used to treat?

  • Non-Small Cell Lung Cancer (NSCLC)
    Imfinzi may be used when your NSCLC has not spread outside your chest, cannot be removed by surgery, and has responded or stabilized with initial treatment with chemotherapy that contains platinum, given at the same time as radiation therapy.
  • Small Cell Lung Cancer (SCLC)
    Imfinzi may be used with the chemotherapy medicines etoposide and carboplatin or cisplatin as your first treatment when your SCLC has spread within your lungs or to other parts of the body, (extensive-stage small cell lung cancer, or ES-SCLC).

Imfinzi was first approved under the FDA’s accelerated approval pathway for the treatment of patients with locally advanced or metastatic urothelial carcinoma (mUC) in 2017. Continued approval for this indication was dependent on the results of the phase III trial, which did not meet its primary endpoints. The urothelial carcinoma indication was voluntarily withdrawn in February 2021.

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