For many years cancer treatment involved chemotherapy, surgery and radiation to stop the growth of cancer cells. But in the past few decades, researchers began studying how the human body’s immune system could be bolstered to fight the disease itself.
After losing friends and family to cancer, James Allison and Tasuku Honjo each became interested in studying cancer and understanding the way it changes the body, particularly immune cells. Their groundbreaking research opened the door for immunotherapy.
Allison’s research focused on the CTLA-4 protein, which regulates T-cells, the workhorses of the immune system. Oftentimes the protein blocks the immune system from attacking cancerous cells. However, Allison developed an antibody to inhibit the CTLA-4 protein and in 2011, the FDA approved ipilmumab, or Yervoy, to treat advanced melanoma.
Yervoy led to the creation of a new drug class called checkpoint inhibitors. Checkpoint inhibitors stop proteins from blocking an immune response and free T-cells to attack malignant tumors. Studies have shown that these inhibitors work in patients with melanoma, as well many other solid tumors.
In 1992, Tasuku Honjo, a professor of immunology at Kyoto University, discovered a protein called Programmed Cell Death Protein 1 (PD1), which is on the surface of immune cells and determines if cells grow normally or turn cancerous. His research showed that the protein inhibits the function of the body’s natural immune defenses.
Working from this discovery, a 2012 study showed that blocking the protein could help the body fight cancer. This led to the development of pembrolizumab, or Keytruda, and nivolumab, or Opdivo, both approved in 2014 to treat melanoma. Subsequent clinical trials have demonstrated the safety and efficacy of these and other checkpoint inhibitors in many different forms of solid tumors, including lung cancer, head and neck cancer, and others.
The groundbreaking research by both Allison and Honjo has opened new doors for cancer research and led to the creation many checkpoint inhibitors, leading to the extensive study of these new medicines. Their discoveries have given many cancer patients a chance at living more normal lives and living longer.