Immunotherapy is a revolutionary approach to treating cancer and other conditions, harnessing the body's own immune system to fight disease. It's an exciting and rapidly evolving field, with clinical trials skyrocketing in the past decade. But what exactly is immunotherapy, and how does it work? In my opinion, the key to understanding its potential lies in exploring its diverse applications and the broader implications for healthcare.
A Brief History of Immunotherapy
The concept of boosting the immune system to prevent disease dates back thousands of years. However, it's only in the past two decades that advanced therapies for a wide range of illnesses have come to the fore. The global registry of clinical trials listed 1,257 trials of immunotherapies between 2006 and 2016, and this figure leapt to 4,591 in the past decade. This surge in interest is due to a growing realization of the immune system's importance, as Adrian Liston, an immunologist and professor of pathology at the University of Cambridge, puts it: "This is the era of immunology."
Cancer Immunotherapies: A Powerful Weapon
Cancer patients have seen great benefits from immunotherapies, with dozens approved for more than 30 types of cancer. Some tumors evade the body's defenses by switching off immune cells, but antibody-based drugs, known as checkpoint inhibitors, reactivate them so they can recognize and attack the malignancies. Highly mutated or "hot" cancers, such as melanoma, can respond particularly well, but not in all patients. This variability in response is a significant puzzle that researchers are working to solve.
One four-year study launched last week aims to recruit thousands of patients with breast, bladder, kidney, and skin cancer to learn what factors affect their outcomes. Other antibody-based medicines tackle cancer differently, such as herceptin, which binds to breast and stomach tumors and flags them for destruction, while blocking chemical signals that tell the cancer to grow. Cancer vaccines, many based on the mRNA technology used in COVID shots, are also showing immense promise, with over 100 in trials.
Immunotherapies for Other Conditions
Cancer immunotherapies tend to ramp up immune attacks; immunotherapies for other conditions aim to dampen them down. For example, simple treatments for allergies such as hay fever and peanut intolerance involve exposing people to small but increasing amounts of the allergy-triggering proteins. Researchers are also testing whether existing immunotherapies can help a broader range of patients, such as using tocilizumab, an immunotherapy for rheumatoid arthritis, to treat depression.
The Promise of T-Cells
Some of the most exciting new immunotherapies draw on last year's Nobel prizewinning work on regulatory T-cells, or Tregs. These cells stand down the immune system once the threat has been dealt with. Liston, the co-founder of a Cambridge spin-out called Aila Biotech, is developing a Treg therapy for multiple sclerosis, a disease caused by immune cells attacking the nervous system by mistake. The therapy aims to boost Tregs in the brain to call off the attack.
The potential for Tregs is vast, with therapies in the pipeline for dementia and autoimmune diseases from type 1 diabetes and rheumatoid arthritis to lupus and chronic inflammation. One therapy under development by Peter Eggenhuizen at Monash University uses Tregs to treat inflammatory bowel disease, a condition that affects at least 7 million people globally.
The Broader Implications
Liston notes that "probably half of all deaths have a component that is immunological." This includes underlying themes across aging, autoimmune diseases, allergies, infectious diseases, and inflammatory diseases like diabetes. The immune system is very easy to change and adapt to our purposes, which is one of the great things about it. As we continue to explore the potential of immunotherapy, we may unlock new treatments for a wide range of conditions and improve the lives of millions of people worldwide.
In conclusion, immunotherapy is a fascinating and rapidly evolving field with immense potential to transform healthcare. As researchers continue to explore its diverse applications, we may unlock new treatments for a wide range of conditions and improve the lives of millions of people worldwide.
