What was the first approved immune-checkpoint inhibitor cancer drug?

Ipilimumab was the first approved immune-checkpoint inhibitor cancer drug.

The U.S. FDA approved ipilimumab, marketed as Yervoy, in 2011 for metastatic melanoma. It blocks CTLA-4, a protein that normally helps restrain T-cell activity. Removing that brake can allow immune cells to attack cancer cells more effectively.

This treatment helped establish modern cancer immunotherapy, which aims to activate the patient’s immune system rather than directly poisoning tumor cells. Its benefits can be durable, but immune activation may also cause inflammation in healthy organs.

Ipilimumab is often confused with pembrolizumab or nivolumab, which target the PD-1 pathway and were approved later. The key first concerns an approved immune-checkpoint inhibitor overall, not the first drug aimed at every checkpoint or the first combination therapy.