The approval of imatinib, a type of cancer growth blocker called ‘tyrosine kinase inhibitor’ twenty years ago, was considered to be “the birth of precision medicine” by Louis DeGennaro, President and CEO of The Leukemia & Lymphoma Society. A decade later, the U.S. Food and Drug Administration approved ipilimumab, the first checkpoint inhibitor to help the immune system better recognize and attack cancer, marking the beginning of the age of immunotherapy.
As part of its normal function, the immune system protects our body from foreign invaders, destroying abnormal cells and potentially curbing the growth of many cancers. Despite the efforts of the immune system, cancer cells have ways to evade destruction. While some have genetic changes that make them less visible to the immune system, others have proteins on their surface that turn off immune cells, and the rest change the normal cells around the tumor so they impede the responses of the immune system.
Immunotherapy, sometimes referred to as biological therapy, is a type of cancer treatment that boosts the body’s natural defenses to fight cancer by activating or suppressing the immune system. The clinical goal is to hence, provide either passive or active immunity against malignancies by harnessing the immune system to target tumors. Immunotherapy uses substances referred to as biological response modifiers ( BRMs). The body usually only produces small amounts of BRMs, however, in the laboratory, large amounts of these BRMs can be generated to provide therapy for cancer, rheumatoid arthritis, and other illnesses by enhancing the immune system’s resistance to such active diseases. Immune checkpoint inhibitors, T-cell transfer therapy, Monoclonal antibodies, treatment vaccines, and immune-system modulators are the types of immunotherapies discovered to date.
For decades, the foundations of cancer treatment were surgery, chemotherapy, and radiation therapy. Drugs that target cancer cells by concentrating on specific molecular changes seen primarily in those cells, such as imatinib and trastuzumab have also cemented themselves as standard treatments for many cancers. However, Immunotherapy has emerged as the “fifth pillar” of cancer treatment in recent years, according to many in the cancer world. Among the several emerging immunotherapy approaches, “CAR T-cell therapy” is the one that has advanced the furthest in clinical developments.
Gaining four new drug approvals to treat numerous blood cancers by the U.S. Food and Drug Administration, chimeric antigen receptor (CAR) T-cell therapy has been said to be the end of the road for cancer treatment. Jeffrey Schriber, Director of Hematologic Malignancies at Cancer Treatment Centers of America, stated “access to CAR T-cell therapy may transform some cancers from acute diseases with poor outcomes to chronic illnesses that may be managed with more positive results.”
CAR T therapy is considered to be a revolutionary treatment that programs a patient’s own altered white blood cells to kill cancer cells. Advanced technology is used to separate white blood cells from the rest of one’s blood cells which are then sent to a specialized laboratory, where they are engineered to produce specific chimeric antigen receptors (CARs) on their surface. These cells are replicated in a laboratory before being returned to the patient. These CAR T-cells are then injected back into one’s bloodstream. This enables the new CARs to help the modified cells latch on to the coordinating antigen on tumor cells – effectively hunting down and killing cancerous cells.
When other blood cancer treatments fail, CAR T-cell therapy has worked, putting some people’s cancers into abeyance. CAR T-cell therapy has the ability not only instructing the T-cell to destroy cancer but also to trigger the T-cell to grow and divide. As a result, even after a single CAR T-cell treatment, the cells remain in your body and target the tumor for months or even years.
Like the two sides of a coin, with benefits comes drawbacks. Inevitably, CAR T-cell therapy consists of several side effects. The most common side effects include:
- Cytokine release syndromes, which involve symptoms that resemble the flu such as high fever, chills, muscle or joint pain, etc. These signs and symptoms might be modest to severe.
- Neurological difficulties such as confusion, tiredness, seizures, agitation, aphasia, etc.
- Anemia and
Stephan Grupp, M.D., Ph.D., of the Children’s Hospital of Philadelphia (CHOP) has led several trials of CAR T cells in children and young adults with all that had recurred or were not responding to existing therapies. In one of his earlier studies, using CD19-targeted CAR T cells, all symptoms of malignancy vanished in 27 of the 30 patients treated, with many of these patients showing no evidence of recurrence years after treatment.
Even those who were early believers in CAR T-cell therapy have been taken aback by the quick advancements and expansion of the therapy. Due to its high success rate, enthusiasm for this technology is very high.
Cover Image Link : Link : https://www.verywellhealth.com/what-are-cancer-cells-2248795
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- National Cancer Institute, (July 30, 2019), CAR T Cells: Engineering Patients’ Immune Cells to Treat Their Cancers, https://www.cancer.gov/about-cancer/treatment/research/car-t-cells
Sheba Medical Center, CAR T Therapy. (2021). Retrieved 1 July 2021, from https://www.shebaonline.org/hemato-oncology/car-t-cell-therapy-in-israel-adults-and-children/?gclid=CjwKCAjw_JuGBhBkEiwA1xmbRaD-9Q2IzHzUKgogoTAu4pBzQ5eMhU8S_1SX2YL0PoRX7OoRBwY38BoC4hEQAvD_BwE