Blood cancer affects millions of people worldwide, creating a challenging situation. A study predicts that in 2025, 66,890 new cancer cases and 23,540 cancer deaths will occur in the United States due to leukemia.
Leukemia, lymphoma, and multiple myeloma are blood cancers that are conventionally treated with a combination of chemotherapy, radiation, and stem cell transplants. The treatments given to the patients depend on the type and stage of cancer.
Chimeric antigen receptor CAR T-cell therapy is an innovative therapy that has evolved recently. It is a highly effective precision-based therapy that has proven to be a boon for treating blood cancers. This therapy gives hope to patients with blood cancer who are not responding to the other standard therapies.
Let’s get into the details of what exactly blood cancer is and how CAR T-cell therapy can treat it precisely.
Cause of Blood Cancer
Blood cells are produced daily by the hematopoietic system in the bone marrow. This system produces blood cells, including red blood cells, white blood cells, and platelets. All these blood cells have specific functions and follow a distinct life cycle. This cycle of cell birth and replacement is continuous, and there is a steady blood supply throughout the body.
Blood cancers are caused when this hematopoietic cycle is disrupted. One of the reasons for such disruptions is cell mutation. When the sequence of genes in the genetic material of a cell changes, it is known as a mutation. Due to mutations in the DNA, the production of blood cells is disturbed, and it follows a different cycle of birth and wear and tear. These mutated disease-fighting cells start to grow uncontrollably, impacting the body’s physiology.
This uncontrolled production of blood cells is known as blood cancer, resulting from a disturbance in blood cell production. The treatment for blood cancer is targeted to regulate the blood cycle and to control the uncontrolled production of blood cells. Conventional treatments for blood cancers have improved survival rates over the years, but many patients develop resistance to standard therapies. Such challenges demanded the innovation of advanced treatments like CAR T-cell therapy.
What is CAR T-Cell Therapy?
CAR T-cell therapy uses the power of a patient’s immune system to fight the cancer.
T-cells are a type of white blood cell (lymphocyte) that are involved in the immune system of the body and resist the entry of any foreign body into our system, such as bacteria and/ or any other antigen. They are also known as fighter cells. Due to this ability of the T-lymphocytes, the patient’s self-T cells are used to destroy cancer cells.
CAR in CAR T-cell therapy stands for ‘Chimeric Antigen Receptor. It is a special protein that helps T cells recognize cancer cells and further destroy them using an immune response.
Functioning of CAR T-Cell Therapy
CAR T-Cell Therapy involves the following steps to be carried out serially:
Collection of T cells
T-cells are collected from patients’ blood through the leukapheresis process. In this process, blood is drawn from the patient and passed through a machine that separates and collects white blood cells while returning the remaining blood components to the patient.
Engineering of T cells
The collected T cells are sent to a specialized laboratory where scientists modify them genetically to produce chimeric antigen receptors on their surface. These CARs are specifically designed to recognize and attach to proteins found on the surface of cancer cells.
Multiplication of T cells
Once the T cells are engineered with the new receptors, they are multiplied in the laboratory to produce millions of cancer-fighting cells. This process typically takes 3 to 4 weeks.
Preparation and Infusion
Before receiving the modified cells, patients usually undergo a brief course of chemotherapy to prepare their bodies for the treatment. The engineered CAR T cells are then infused back into the patient’s bloodstream, where they begin their search-and-destroy mission against cancer cells.
Monitoring and Action
Once in the body, these modified T-cells multiply and continue their cancer-fighting activity. They can remain in the body for months or even years, providing long-term surveillance against cancer recurrence.
Side Effects of CAR T-Cell Therapy
Cytokine Release Syndrome (CRS)
CAR T-cell therapy has the power to treat many hard-to-treat cancers, but it can also cause serious side effects. One of the side effects of this therapy is Cytokine Release Syndrome (CRS). This treatment must be provided only by specialists under their supervision. As CAR T cells grow and work inside the body, they release cytokines, activating the immune system. If too many cytokines are released, it can lead to severe side effects.
A few of the side effects are as follows:
● High fever and chills
● Severe fatigue
● Difficulty breathing
● Nausea and vomiting
● Low blood pressure
● Rapid heartbeat
● Organ complications in severe cases
Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS)
Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS) is another life-threatening neurological complication associated with CAR-T cell therapy. This condition affects the nervous system.
Symptoms of this syndrome include:
● Confusion and delirium
● Difficulty speaking or understanding speech
● Seizures
● Loss of balance
● Headaches
● Tremors
● Altered consciousness
Treatment Success of CAR T-Cell Therapy
Chimeric Antigen Receptor CAR T-Cell Therapy is the best treatment for various hematological malignancies, particularly B-cell cancers associated with B-cell lymphocytes.
Complete Remission
Studies indicate that CAR T-cell therapy can achieve remission rates exceeding 50% in patients with relapsed or refractory B-cell malignancies. For example, a study from Massachusetts General Hospital reported a complete response rate of 56% among 100 patients treated for lymphoma, myeloma, or B-cell acute lymphoblastic leukemia (B-ALL)
Durability of Response
The durability of responses varies by cancer type. For example, CD19-targeted CAR T-cells have shown prolonged remissions in B-cell malignancies, while BCMA-targeted therapies for multiple myeloma often result in shorter remissions. In patients with severe chemotherapy-refractory diseases, complete remission rates can be as high as 81% to 90%.
Overall Response Rates
In clinical trials, overall response rates have reached up to 85%, with significant proportions of patients achieving minimal residual disease negativity.
Quality of Life Improvements
Patients undergoing CAR T-cell therapy often report improvements in life quality post-treatment. A study found that while initial symptoms may lead to a decline in quality of life shortly after treatment, significant improvements are typically observed six months later.
CAR T-cell therapy represents a remarkable advancement in cancer treatment, offering hope to patients with limited options. As research continues and technology improves, this approach may become even more effective and accessible to patients worldwide.
FAQs:
What does CAR T-cell therapy do?
CAR T-cell therapy uses patients’ T-lymphocyte cells, which are a type of white blood cell. These cells participate in the immune system of our body and have the ability to fight antigens. They are genetically altered in a laboratory to make them efficient in locating and destroying cancer cells effectively.
What is the principle of CAR T-cell therapy?
CAR T-cell therapy involves collecting T cells from the patient and re-engineering them in the laboratory to produce proteins on their surface called chimeric antigen receptors, or CARs. The CARs identify and bind to the antigens or specific proteins on the surface of the cancer cell and eliminate them.
What diseases can CAR T-cell therapy treat?
CAR T-cell therapy treats B-cell acute lymphoblastic leukemia for pediatric and adult patients, certain B-cell lymphoma subtypes, high-grade B-cell lymphoma, follicular lymphoma, mantle cell lymphoma, and multiple myeloma.
What are the advantages of CAR-T cells?
The advantage of CAR-T cell therapy is that it requires a short time. It is better than other traditional cancer treatments in long-term remission with a better quality of the patient’s life. It can be considered for patients who are not responding to conventional therapy.
Who invented CAR T-cell therapy?
CAR T-cell therapy was invented by Dr. Carl June.
What are the disadvantages of CAR T-cell therapy?
CAR-T treatment needs to be customized for each patient. The T-lymphocytes are part of the body’s immune system, and in some patients, they can exacerbate severe side effects. Some patients do not tolerate the treatment because of the severity of side effects. Hence, it requires tremendous caution and supervision.