What type of drug is Imfinzi?

Imfinzi (durvalumab) is a programmed death-ligand 1 (PD-L1) blocking antibody (also called an immune checkpoint inhibitor). It is used to treat various cancers, including non-small cell lung cancer (NSCLC), small cell lung cancer (SCLC), biliary tract cancer (BTC), hepatocellular carcinoma (HCC), endometrial cancer, and muscle-invasive bladder cancer (MIBC).

What are immune checkpoints?

Immune checkpoints 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 cannot 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)
preventing 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)
  - Before and after surgery: In combination with chemotherapy that contains platinum to treat NSCLC that can be removed by surgery, and is not known to have an abnormal EGFR or ALK gene.
  - Unresectable NSCLC: Used alone to treat NSCLC that has not spread outside the 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.
  - Metastatic NSCLC: Combined with tremelimumab-actl and platinum-based chemotherapy to treat NSCLC that is metastatic (has spread to other parts of the body), and does not have an abnormal EGFR or ALK gene.
• Small Cell Lung Cancer (SCLC)
  - Limited-stage small cell lung cancer (LS-SCLC) that cannot be removed by surgery, and has responded or stabilized after initial treatment with chemotherapy that contains platinum, given at the same time as radiation therapy.
  - Extensive-stage small cell lung cancer: Combined with the etoposide and either carboplatin or cisplatin as a first treatment when the SCLC has spread within the lungs or to other parts of the body, (extensive stage small cell lung cancer, or ES-SCLC).
• Biliary Tract Cancer (BTC): Combined with gemcitabine and cisplatin to treat BTC, including cancer of the bile ducts (cholangiocarcinoma) and gallbladder cancer, that is locally advanced (has spread to nearby tissues), or is metastatic.
• Hepatocellular Carcinoma (HCC): Combined with tremelimumab-actl to treat hepatocellular carcinoma that is unresectable (cannot be removed by surgery).
• Endometrial Cancer: Combined with chemotherapy medicines carboplatin and paclitaxel followed by Imfinzi alone to treat endometrial cancer that is advanced (has spread), or is recurrent (has come back), and is mismatch repair deficient (dMMR) as determined by a laboratory test.
• Muscle invasive bladder cancer (MIBC): Combined with gemcitabine and cisplatin followed by Imfinzi alone with radical cystectomy.

Summary

Imfinzi enhances immune system function by blocking PD-L1, helping T-cells recognize and attack cancer cells. Its diverse applications in lung, liver, endometrial, biliary, and bladder cancers make it a critical immunotherapy option.