Clinical trials for immunotherapies have increased sharply over the past decade as scientists apply knowledge of the immune system to develop new treatments. Cancer therapies lead the field, though researchers are also exploring applications for infections, allergies, brain disorders, and autoimmune conditions. Immunotherapies are biological treatments that use the immune system to prevent, manage, or combat diseases. Common examples include vaccines that prepare the body to identify pathogens, as well as therapies that strengthen weak immune responses or reduce excessive ones. Some approaches rely on engineered immune cells or laboratory-produced antibodies. Historical efforts to enhance immunity extend back thousands of years, but modern immunotherapies for diverse illnesses have advanced significantly in recent decades. A global registry recorded 1,257 immunotherapy trials from 2006 to 2016, rising to 4,591 in the following ten years. Cancer immunotherapies have provided substantial benefits, with dozens now approved for over 30 cancer types. Certain tumors suppress immune activity, but checkpoint inhibitor drugs can restore this function to target malignancies. Highly mutated cancers often respond well, though outcomes vary among patients. Ongoing research involving thousands of individuals with breast, bladder, kidney, and skin cancers aims to identify factors influencing success. Other antibody treatments, such as those used for breast and stomach tumors, mark cancer cells for elimination while interrupting growth signals. Cancer vaccines, including those based on mRNA technology, are also advancing, with more than 100 in clinical trials. Additional methods involve harvesting and expanding a patient’s own immune cells or engineering them through CAR-T therapy to attack cancer. Immunotherapies for non-cancer conditions typically aim to moderate immune activity rather than enhance it. Treatments for allergies involve gradual exposure to triggering substances. Researchers are testing existing drugs, including one for rheumatoid arthritis, for potential benefits in depression. New approaches based on regulatory T-cells seek to calm misguided immune attacks, with applications under development for multiple sclerosis and brain injury recovery.
