How CAR-T Therapy Works — Step by Step

CAR-T therapy is a sequence, not an appointment. Your T cells are collected from your blood, shipped frozen to a laboratory, given a new receptor gene, grown into a dose and tested. A short chemotherapy course follows, then the cells are infused back in one sitting. Weeks of monitoring complete it.

Written out like that it sounds like six lines. Lived, it is six to eight weeks in which one member of the family stops working, someone stays within reach of an accredited centre around the clock, and the treatment clock starts long before the infusion date anyone quotes you. That gap between the summary and the calendar is what this page exists to close.

It is worth saying early that most patients are not candidates. Approved CAR-T use sits almost entirely in certain relapsed or refractory blood cancers, after earlier lines of treatment have been tried. Solid tumours are not treated with CAR-T in routine care. Eligibility is decided by a haemato-oncologist at an accredited centre, and is covered in who is eligible for CAR-T therapy.

Said plainly, before anything else: CION Cancer Clinics does not provide CAR-T cell therapy or any other cell therapy. We do not administer it, stock it or manufacture it. This page is orientation and referral guidance so that you can follow what a specialist centre is proposing, and so we can point you to the right centre when that is genuinely the next step.

1. 1

   Leukapheresis — the collection day

   Blood runs through a machine that keeps the T cells and returns everything else to you. It takes a few hours. No surgery, no general anaesthetic, usually a day-care visit.

2. 2

   Freezing and shipping

   The collection is cryopreserved and sent to a licensed manufacturing site under a tracked cold chain. A chain-of-identity label follows the batch in both directions.

3. 3

   The gene goes in

   A viral vector inserts the gene for the chimeric antigen receptor. Nothing from another person is added. This is the step that gives your own cells a target to recognise.

4. 4

   Growing the dose

   The modified cells are multiplied over several days until there are enough for one dose. Most of the waiting families experience sits here and in the testing that follows.

5. 5

   Release testing

   Sterility, identity, potency and viability must all pass. A failed batch cannot be swapped from a shelf. The process restarts at collection, which costs weeks.

6. 6

   Bridging treatment while you wait

   Many patients need treatment during the manufacturing gap to hold the disease steady. Ask the centre what the bridging plan is and where it will be given.

Process description follows patient-education material from guideline bodies including NCCN and ESMO. Exact steps and timings differ between products and manufacturing sites — the treating centre’s own written schedule is the one that governs your case.

Ranges above reflect published patient-education guidance from bodies including NCCN and ESMO and vary by product, centre and country. Ask your treating centre for its own written timeline before you book leave, travel or accommodation.

1. 1

   Identity check at the bedside

   Two staff match the batch label to you by name and identifiers. A CAR-T dose belongs to one named person and can be given to nobody else.

2. 2

   Premedication

   Usually paracetamol and an antihistamine. Steroids are generally avoided around the infusion, because they can blunt the very cells being given.

3. 3

   Thawing at the bedside

   The bag is thawed just before use and infused promptly. Some people notice a garlic or sweetcorn-like taste or smell from the freezing agent. It passes.

4. 4

   The infusion itself

   The cells run through a central line, typically in well under an hour. There is no radiation, no operation and nothing to feel in most cases.

5. 5

   Observation, then the countdown begins

   Temperature, pulse and blood pressure are recorded closely. Day zero is a reference point: everything afterwards is counted from it.

Practical conditions come with this window, and they are not negotiable at most centres: an adult caregiver present around the clock, staying within a defined travel time of the hospital, no driving for a set period, and a phone that is answered day and night. The reaction families most want explained in advance is covered in cytokine release syndrome, the main CAR-T complication.

Response varies widely by disease, prior treatment and individual fitness. Guideline bodies including NCCN and ESMO describe meaningful responses in a proportion of patients with relapsed or refractory disease, and are equally clear that it does not work for everyone. Ask the treating centre for the realistic picture in your specific case, in writing.

• Funding clearance — approval paperwork often runs longer than the clinical workup and can quietly hold the whole slot.
• Slot availability — accredited centres are few and beds are allocated, so the collection date may be weeks after you are declared eligible.
• Disease progression during the wait — the reason bridging therapy exists, and a genuine risk to ask the centre about directly.
• A batch that fails release testing — there is no replacement on a shelf. Collection has to be repeated, which resets weeks of the calendar.
• Fitness on the day — infection, organ function or performance status can postpone lymphodepletion even after the cells have arrived.

Cost belongs in the same conversation. Reported list prices for approved CAR-T products internationally have sat in the region of several crore rupees for the infusion alone, before hospital stay and monitoring; India’s domestically developed CAR-T therapy was reported at a small fraction of that at launch. Treat both as indicative, as of August 2026 — they come from published manufacturer and news reports, not from a CION rate card, and CION quotes no price for a therapy it does not provide. The differences between the two routes are set out in Indian-made CAR-T versus imported.

No. CION Cancer Clinics does not administer, stock or manufacture CAR-T cell therapy or any other cell therapy. If a page, an agent or a forwarded message tells you otherwise, it is wrong.

What we do is read your reports, tell you whether your diagnosis is even in a category where CAR-T is discussed, walk you through what the pathway would mean week by week, and give you a written second opinion on the treatment you have already been offered. Where referral to an accredited cell-therapy centre is the right next step, we will say so. The immunotherapy given as day care at CION centres is checkpoint-inhibitor therapy — a different class, a different schedule and a different side-effect pattern. Response-assessment PET-CT during that treatment is coordinated at partner imaging centres rather than owned by CION.

Related reading

• Who Is Eligible for CAR-T Therapy? — the question that comes before this one: which diagnoses, which lines of treatment, and what the workup actually tests.
• Cytokine Release Syndrome (CRS): The Main CAR-T Complication — what the monitored window is monitoring for, in detail, and why it decides where you stay.
• Indian-Made CAR-T vs Imported: Is There a Difference? — useful if cost or travel is the real constraint on whether this pathway is reachable.
• Immunotherapy at CION Cancer Clinics — the treatments CION does provide, how eligibility is assessed, and what a first consultation covers.

This page is general information and does not replace a consultation. CION Cancer Clinics does not provide CAR-T or cell therapy; immunotherapy at CION means checkpoint-inhibitor treatment given as day care, with response-assessment PET-CT coordinated at partner imaging centres. Timings are typical ranges, not promises, and cost figures are indicative, as of August 2026, drawn from published reports. Only your treating haemato-oncologist, reviewing your complete case, can tell you what applies to you.

Most families meet this timeline with no warning

If you have been told CAR-T is being considered, ask us what the next eight weeks would actually involve. You will get a plain answer, including when the answer is that it does not apply.