NEW YORK, July 14 — When James Allison and Tasuku Honjo shared the Nobel Prize in Physiology or Medicine in 2018, they stood on a stage built from a radical idea: that the human immune system could be trained to hunt and destroy cancer. Immunotherapy works by using the body’s own immune system to recognize and destroy cancer cells. It is not a single drug or procedure, but a family of approaches, each with its own mechanism and history.
One of the most prominent strategies involves checkpoint inhibitors. These drugs block proteins — such as PD-1, or programmed cell death protein 1, and CTLA-4, cytotoxic T-lymphocyte-associated protein 4 — that normally prevent T cells from attacking cancer cells.
The first checkpoint inhibitor to reach patients was ipilimumab, an anti-CTLA-4 therapy approved by the U.S. Food and Drug Administration in 2011 for metastatic melanoma. Two more followed in 2014: pembrolizumab and nivolumab, both targeting PD-1. Another approach, CAR-T cell therapy, takes a more personalized route.
A patient’s own T cells are extracted, genetically engineered in a lab to express a chimeric antigen receptor that targets cancer cells, and then infused back into the patient. The first such therapy, tisagenlecleucel, sold as Kymriah, won FDA approval in 2017 for B-cell precursor acute lymphoblastic leukemia.
By 2023, six CAR-T therapies had been approved by the FDA.
A longer history than many realize
Immunotherapy’s roots stretch back further than checkpoint inhibitors or engineered cells. Monoclonal antibodies — lab-made molecules that bind to specific targets on cancer cells — entered the clinic decades ago. Rituximab was approved in 1997 for non-Hodgkin lymphoma.
Trastuzumab, for HER2-positive breast cancer, followed in 1998. The global immunotherapy market reflected this momentum.
It was valued at approximately $162 billion in 2022, with projections to grow to over $300 billion by 2030. Behind the market numbers are individual stories. A patient with metastatic melanoma who received ipilimumab in 2011 and is still alive today.
A child with leukemia whose T cells were reprogrammed and sent back into battle. Researchers in labs across the world, refining the next generation of treatments, looking for ways to make these powerful therapies work for more people, with fewer side effects.
The science continues to move fast. Combinations of checkpoint inhibitors are being tested. Newer CAR-T designs aim to target solid tumors, a tougher challenge than the blood cancers where the approach has already succeeded.
And researchers are probing why some patients respond dramatically while others do not at all — a question that, if answered, could unlock the next wave of progress. For now, immunotherapy stands as one of the most active frontiers in cancer medicine. It is not a cure for every patient, but it has changed what is possible. Consult your doctor for medical advice.
