Biologic response modifier therapy is a type of treatment that helps the body's immune system fight diseases, particularly cancer. This therapy uses substances made from living organisms or their products to enhance or restore the immune response. It can help the body recognize and attack cancer cells more effectively. This therapy includes various approaches, such as monoclonal antibodies, cytokines, and vaccines. Each of these methods works differently but aims to improve the immune system's ability to target and destroy abnormal cells. Biologic response modifiers can be used alone or in combination with other treatments, like chemotherapy.