One of humanity’s greatest challenges now is cancer, for which there is currently no proven cure. But with the first patient using India's CAR-T cell therapy being fully cured of cancer, hope has been sparked.

Dr (Col) V K Gupta, a 64 years old gastroenterologist in Delhi, became one of the first patients to receive CAR-T cell therapy, a ground-breaking treatment that genetically reprograms a patient's immune system to fight cancer. This happened just months after India's drug authority approved its commercial use.

The treatment in India cost only Rs 42 lakhs, while in abroad, it is about Rs 3–4 crores. Mr. Gupta is the first patient to be declared "currently free of cancer cells" by medical professionals at Tata Memorial Hospital, where the treatment was performed.

CAR-T Therapy: What is it?

It is a therapy in which the immune system's T cells - a subset of lymphocytes - of a patient are engineered in a lab to target cancer cells. Blood is drawn from the patient to extract T lymphocytes.

The T cells are subsequently provided with the gene for a unique receptor that attaches to a specific protein on the patient's cancer cells in the lab.

Chimeric antigen receptors (CARs) are the unique name for these receptors. The patient receives an injection of a large number of CAR T cells that have been produced in the lab.

Certain blood cancers are treated with CAR T-cell therapy, and other cancer types are also being explored for this treatment option. Also known as T-cell therapy using chimeric antigen receptors.

When other cancer treatments are not working, CAR T therapy can be particularly effective against some cancer types. At now, the FDA has approved CAR T therapy for the treatment of many hematological malignancies, such as Leukemia, multiple myeloma, and Lymphoma.

Potential adverse reactions to CAR-T treatment

Two primary types of side effects are identified that may demands further attention:

• cytokine release syndrome (CRS)

• immune effector cell-associated neurotoxicity syndrome (ICANS)

Cytokine release syndrome (CRS):

Proteins called cytokines are typically secreted by cells of the immune system as a means of intercommunication. Numerous cytokines are released into the body by an army of CAR T-cells attacking cancer cells, and these cytokines can have a major negative impact on health. it is called cytokine release syndrome. It may start a few hours, days, or weeks following the course of treatment. Among the symptoms could be:

• fever

• low blood pressure

• decrease in red or white blood cells

• anorexia

• feeling lightheaded

• irregular heartbeat

• breathlessness

• diarrhea, vomiting, and in muscles ache or joint 

• edema.

Cytokine release syndrome has the potential to be fatal if it is not identified and treated immediately. Among the possible treatments are Corticosteroids and medications that target particular cytokines such as anakinra, siltuximab, and tocilizumab.

Immune effector cell-associated neurotoxicity syndrome (ICANS):

Neurotoxicity is the term for injury to the nervous system or brain that is also known as immune effector cell-associated neurotoxicity syndrome, or ICANS. It is often short-lasting and may occur with CAR T-cell treatment.

Neurotoxicity typically shows up as a week or so following therapy, however it might happen later. It nearly always appears in individuals with a history of cytokine release syndrome. 

A headache, delirium, encephalopathy, aphasia, lethargy, difficulty concentrating, agitation, tremor, seizures, and signs of elevated cerebral pressure are only a few of the many and non-specific clinical presentations of ICANS.

Rapid advancement to obtundation, coma, and death is possible in a small percentage of cases. After receiving CAR T-cell infusion, the majority of cases of onset occur within one week.

The underlying cause and severity of ICANS determine how it should be treated. Many treatments focus on controlling particular manifestations while providing support such as antiseizure drugs for seizures. Corticosteroids like dexamethasone or methylprednisolone, are examples of anti-inflammatory therapies.

In more severe cases, or if concurrent cytokine release syndrome is present, anti-cytokine agents, such as tocilizumab or anakinra, may be used. Some individuals may die from complications including cerebral hemorrhage, uncontrolled cerebral edema leading to cerebral herniation, or multiorgan failure, or they may have persistent neurological abnormalities.

Other severe adverse effects that might need to be attended to by a doctor include:

• abnormal blood concentrations of essential minerals in allergy conditions,

• possibility of bleeding,

• severe infections,

• bruising.

CAR-T therapy benefits over other cancer treatments

Benefits from CAR T-cell therapy can extend for several years, making it another "thriving drug."

The cells may identify and combat cancer cells if and when there is a return because they have the ability to live a long time in the body.

The main benefit of CAR T-cell therapy is how little time it takes to treat patients; it just requires a single infusion and two weeks of inpatient care at most. Compared to stem cell transplants, when severe chemotherapy is utilized, most patients recover significantly faster because aggressive chemotherapy is not used in this case.

Though CAR T-cell therapy is now licensed for the treatment of individuals in whom transplant is not anticipated to be curative or in patients who relapse after transplant, it may eventually even replace most forms of transplantation.

Blood cancer clinical trials have demonstrated that CAR T-cell therapy can help patients achieve long-lasting remissions, even in cases where the malignancy returned despite receiving repeated therapies.