Consultant, Haemato-Oncology & BMT, Fortis Hospital, Shalimar Bagh, New Delhi
Part 2 of 8 in CAR-T Cell Therapy
What Is CAR-T Cell Therapy and How Does It Work?
September 6, 2026
Chimeric antigen receptor T-cell therapy, better known as CAR-T, is a cellular therapy that uses the power of a patient's own immune system, re-engineered through genetic engineering, to target cancer cells in a way conventional chemotherapy cannot.
Turning a T-cell into a cancer-hunting cell
The principle is straightforward to describe, even though the manufacturing behind it is not: T-cells are taken from the patient's own body, and a chimeric antigen receptor is attached to each one, turning an ordinary T-cell into a CAR-T cell that is cancer-specific and targeted. Once infused back into the body, that engineered receptor lets the T-cell recognise and neutralise the cancer directly. Only autologous CAR-T, built from a patient's own cells, is currently available; donor-derived CAR-T is not yet in use.
Collection: the most crucial step
T-cells are collected from the patient through an apheresis machine, the same equipment used to collect a stem cell donation or single donor platelets. No mobilisation drugs are required beforehand; a vein is connected to the machine and T-cells are filtered out directly from the blood. This collection step is the most crucial part of the entire process, because if an adequate number of T-cells is not collected, the CAR-T cannot proceed at all. That happens in roughly 5 to 10 percent of cases, and when it does, the only option is to wait, typically around 6 months, before attempting collection again.
Engineering and expanding the cells
Once collected, the T-cells are sent to a dedicated laboratory that follows strict manufacturing protocols. There, the chimeric antigen receptor targeting CD19, a marker found on B-cells, is attached to each T-cell, and the resulting CAR-T cells are expanded to the required dose of approximately 5 million CAR-T cells per kilogram of the patient's body weight. Even after successful collection, there remains roughly a 2 percent chance that the CAR-T fails to expand properly in the lab, which adds to the overall time the complete process takes.
This article is based on a Jivo Masterclass session conducted by Dr. Akash Khandelwal, Consultant, Haemato-Oncology & BMT, Fortis Hospital, Shalimar Bagh, New Delhi. The article has been summarised with the assistance of an AI tool from the original masterclass recording. Watch the full Masterclass recording
This guide is based on a live Jivo Masterclass: Dr. Akash Khandelwal taught doctors across Africa on March 9, 2025.
FROM THE LIVE Q&A
Dr. Anh (Hong) Nguyen (Vietnam)
For the approved indications of relapsed or refractory diffuse large B-cell lymphoma and B-cell ALL, patients need to be over 15 years old. What is the name of the CAR-T product available in India, so I can look up the clinical trial research myself?
Dr. Akash Khandelwal
There are two CAR-T products commercially available in India right now, both targeting CD19. One is NexCAR19, made by ImmunoACT, which has been commercially available in India since December 2023, so there is more than a year of experience with it. The second product was launched only about a month back and is still underutilised. Both target CD19, the marker responsible for the B-cell response, so B-cell ALL and B-cell lymphoma are the appropriate targets, not Burkitt lymphoma (the CAR-T construct needed is different) or CNS lymphoma (which does not respond as well).
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Frequently Asked Questions
I also attend a gene and cell therapy conference in Vietnam, and my institution is developing its own academic clinical trial in CAR-T. Are there upcoming CAR-T trial opportunities in India that international patients could join?▼
Fortis Shalimar Bagh is in talks to run its own CD19-directed CAR-T clinical trial for lymphoma and leukemia. Myeloma CAR-T trials are also upcoming from other companies and should be commercially available in India by year end. However, international patients cannot be enrolled in Phase 1 or Phase 2 trials, since these require longer follow-up before DCGI grants approval based on long-term data for commercial or international use. Until then, the CD19 CAR-T that is already commercially available is the only option for international patients.
Do you have specific nutritional considerations for patients undergoing CAR-T cell therapy, especially in a setting with very limited access to CAR-T treatment centres?▼
Adequate T-cell collection is the rate-limiting step for CAR-T, and nutrition can affect that. If enough T-cells aren't collected, the only option is to wait and reattempt collection after about 6 months. Beyond that, nutrition doesn't play a major role, since the chemotherapy used for CAR-T is not very toxic and even a frail patient can undergo CAR-T therapy. Nutrition plays a bigger role in bone marrow transplants than it does in CAR-T cell therapy.
Can you elaborate further on the vein-to-vein time you mentioned, around 19 days: how exactly are the cells collected and processed before the transplant?▼
T-cells are collected the same way a stem cell or single-donor platelets are collected, through an apheresis machine. No drugs are given before collection; a vein is all that's needed, and if an adequate number of T-cells is found, CAR-T manufacturing can go ahead.
Is there any risk to hair regrowth after the chemotherapy and CAR-T treatment?▼
The conditioning chemotherapy is just cyclophosphamide and fludarabine, which can cause cytopenias and neutropenia, but this is manageable since the dosing isn't very high, so fitness is not usually a major factor. It's the CAR-T related side effects that vary more from patient to patient. If the disease is well controlled going in, complications are less likely, but even with good control, side effects such as cytokine release syndrome or, less commonly, ICANS (which can affect the brain) can occur. Whatever side effects arise are manageable and not life-threatening: no deaths from CAR-T related side effects have been seen, and it isn't well documented even in the long-term data.
What are the specific cancer cells targeted by CAR-T, and can it be applied to ovarian or cervical cancers?▼
Not yet - it hasn't shown good promise there so far. Currently CAR-T is only available for B-cells, targeting CD19, and this has shown long-term responses based on research done in the US, with a large subset of patients still in remission after CD19-targeted CAR-T infusion. Other categories are in development too, such as dual-target CARs and attachments that help CAR-T expand and persist for longer, but currently only CD19 CAR-T can be offered, since that's what's commercially available in India.
How is CAR-T cell therapy made?▼
T-cells are collected from the patient via apheresis, engineered in a lab to carry a chimeric antigen receptor targeting CD19, then expanded to about 5 million CAR-T cells per kilogram of body weight before being infused back into the patient.
Why is T-cell collection considered the most crucial step?▼
If an adequate number of T-cells is not collected, the CAR-T cannot be manufactured at all. This happens in roughly 5 to 10 percent of cases, requiring a wait of about 6 months before another collection attempt.
Is CAR-T made from the patient's own cells or a donor's?▼
Currently only autologous CAR-T, built from the patient's own T-cells, is available. Donor-derived CAR-T is not yet in use.
In This Series: CAR-T Cell Therapy
- 1.CAR-T Cell Therapy
- 2.What Is CAR-T Cell Therapy and How Does It Work?
- 3.The CAR-T Cell Therapy Timeline: From Collection to Infusion
- 4.Who Is Eligible for CAR-T Cell Therapy?
- 5.Managing Complications After CAR-T Cell Infusion
- 6.CAR-T Cell Therapy Outcomes: What the Data Shows
- 7.The Cost and Availability of CAR-T Cell Therapy in India
- 8.The Future of CAR-T Cell Therapy: Beyond Lymphoma and Leukaemia