Checkpoint Inhibitors

When the immune system is working well, it attacks invaders and not normal cells. If it went after all the normal cells in the body, we would all have auto-immune diseases, like lupus or type 1 diabetes. The normal immune system has “checkpoints” to stop the immune cells from attacking everything. When checkpoints are turned on, they stop the immune system from attacking.

Cancer can trick the body’s natural defenses into not attacking. Then the cancer cells keep growing without being slowed down or stopped. The cancer makes proteins that turn on the checkpoints. With those checkpoints turned on, the immune system does not fight the cancer well.

Some treatments work to fix the problem at the checkpoint. Treatments called “checkpoint inhibitors” block the checkpoint so the cancer can’t turn it on. This keeps the immune system active and working against the cancer. Many of these checkpoint inhibitors are monoclonal antibodies. They target a specific protein in the checkpoint.

One checkpoint that is commonly targeted for lung cancer is the PD-1/PDL-1 checkpoint.

A number of checkpoint inhibitor treatments have been approved for stage III and stage IV lung cancer.

  • Immunotherapy treatments approved for stage III non-small cell lung cancer patients
  • Immunotherapy treatment approved for stage IV non-small cell lung cancer patients
  • Immunotherapy treatment approved for small cell lung cancer