THOUGHT LEADERSHIP

In 2021, FDA has so far approved six antibodies against PD-1 or PD ligand 1 (PD-L1) for more than 75 indications. Ipilimumab remains the only FDA approved anti-CTLA-4 antibody, in melanoma indications and, in combination with nivolumab (an anti-PD‑1 antibody), in a number of other indications.

Basic research in the 1990’s showed that antibodies aimed at a cell surface marker called cytotoxic T-lymphocyte antigen 4 (CTLA-4) stimulated an immune response that resulted in the killing of the tumor cells. Another cell marker, programmed death-1 (PD-1), was found to have the ability to prevent the immune system from killing cancer cells. These discoveries led to the development of cancer therapy using inhibition of negative immune regulation.

We knew that immunotherapy finally had a breakthrough when James Allison and Tasuku Honjo received the Nobel Prize in Physiology or Medicine in 2018 for “discovery of cancer therapy by inhibition of negative immune regulation.”