[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Immunology](https://durgical.com/en/immunology/) › [Transplant, tumors and immunotherapy](https://durgical.com/en/immunology/#a-transplant) › Cancer immunotherapy: checkpoint inhibitors, CAR-T and vaccines

[Immunology](https://durgical.com/en/immunology/) · [Transplant, tumors and immunotherapy](https://durgical.com/en/immunology/#a-transplant)

# Cancer immunotherapy: checkpoint inhibitors, CAR-T and vaccines

- Topic

Some cancer treatments do not attack the tumour directly: they release the brakes of the immune system or train the patient's own T cells to find the cancer.

Updated 2026-11-01

## Key points

- Anti-PD-1 (nivolumab, pembrolizumab), anti-PD-L1 (atezolizumab, durvalumab), anti-CTLA-4 (ipilimumab).
- CTLA-4 = early brake (priming in the node); PD-1 = late brake (exhaustion in the tumour).
- Checkpoint side effects are autoimmune: colitis, hepatitis, pneumonitis, endocrinopathies.
- CAR-T = patient's T cells + antibody-based receptor, MHC-independent; CD19 and BCMA targets.
- Cytokine release syndrome is IL-6 driven; tocilizumab blocks the IL-6 receptor.
- MSI-high tumours respond to PD-1 blockade regardless of tissue of origin.

## What it is

Cancer immunotherapy uses the immune system to recognise and destroy tumour cells. The main tools are immune checkpoint inhibitors (antibodies that release the PD-1, PD-L1, CTLA-4 or LAG-3 brakes on T cells), adoptive cell therapy (CAR-T cells, tumour-infiltrating lymphocytes), therapeutic monoclonal and bispecific antibodies, treatment vaccines and broad immune modulators. Because they unleash immunity, their typical side effects are autoimmune-like inflammation and, for CAR-T, cytokine release syndrome.

## Key facts

- CTLA-4 acts early, limiting T-cell priming in lymph nodes; PD-1 acts late, in tissues, where it marks exhausted T cells.
- Tumours with many mutations (melanoma, smoking-related lung cancer, MSI-high tumours) display more neoantigens and respond better to checkpoint inhibitors.
- A CAR joins an antibody fragment (scFv) that binds a surface antigen to CD3ζ and a costimulatory domain (CD28 or 4-1BB): it recognises antigen without MHC.
- CAR-T cells are made from the patient's own T cells, modified in a laboratory with a viral vector, expanded and infused back; production takes several weeks.
- Current CAR-T targets: CD19 (B-cell acute lymphoblastic leukaemia, large B-cell lymphoma) and BCMA (multiple myeloma).
- Other approaches: tumour-infiltrating lymphocytes, bispecific T-cell engagers (for example CD19 × CD3), intravesical BCG for bladder cancer and preventive vaccines (HPV, hepatitis B) that prevent virus-driven cancers.

## Checkpoint inhibitors by class

| Class | What it blocks | Examples | Notes |
| --- | --- | --- | --- |
| Anti-PD-1 | PD-1 on exhausted T cells inside the tumour | Nivolumab, pembrolizumab | Melanoma, lung cancer, kidney cancer, Hodgkin lymphoma, tumours with mismatch repair deficiency (MSI-high), among others |
| Anti-PD-L1 | PD-L1 made by tumour and stromal cells | Atezolizumab, durvalumab | Lung and bladder cancer, among others; PD-L1 staining can help select patients |
| Anti-CTLA-4 | CTLA-4, which competes with CD28 for B7 during priming in lymph nodes | Ipilimumab | Melanoma; often combined with anti-PD-1, with more side effects |
| Anti-LAG-3 | LAG-3, another inhibitory receptor on T cells | Relatlimab | Combined with nivolumab in advanced melanoma |

## Markers

- PD-1
- PD-L1
- CTLA-4
- LAG-3
- CD19
- BCMA
- MSI-high
- IL-6

## Clinical notes

- Immune-related adverse events of checkpoint inhibitors: dermatitis, colitis, hepatitis, pneumonitis, thyroiditis, hypophysitis, type 1 diabetes, nephritis and, rarely, myocarditis.
- CAR-T: cytokine release syndrome (fever, low blood pressure, driven by IL-6; treated with the IL-6 receptor blocker tocilizumab and corticosteroids) and neurotoxicity (ICANS: confusion, speech problems).
- Anti-CD19 CAR-T also destroys normal B cells, giving long-lasting B-cell aplasia and low antibody levels.
- Tumours escape immunotherapy by losing the target antigen or MHC class I, or by recruiting regulatory T cells and suppressive myeloid cells.

## Memory aid

Checkpoint inhibitors cut the brake cables (CTLA-4 at the start of the race, PD-1 at the finish line); CAR-T installs a satnav that drives the T cell straight to CD19 or BCMA.

## Test yourself

Think of the answer, then tap the question to see it.

## What is the difference between where CTLA-4 and PD-1 act?

CTLA-4 limits T-cell priming in lymph nodes by competing with CD28 for B7; PD-1 inhibits already activated T cells in peripheral tissues and tumours.

## Why can CAR-T cells recognise tumour cells that have lost MHC class I?

The CAR uses an antibody fragment that binds a surface antigen directly, without MHC presentation.

## Which cytokine drives cytokine release syndrome after CAR-T therapy, and what drug blocks its receptor?

IL-6; tocilizumab blocks the IL-6 receptor.

## A patient on a checkpoint inhibitor develops diarrhoea and fatigue with low cortisol. Which adverse events should be considered?

Immune-related colitis and hypophysitis (or adrenal involvement), autoimmune-like effects of releasing T-cell brakes.

## Which antigen is targeted by CAR-T cells in multiple myeloma?

BCMA (B-cell maturation antigen).

[Add to my cards (5)](https://durgical.app/estudiar/?add=/en/immunology/cancer-immunotherapy-checkpoint-inhibitors-car-t-and-vaccines/)

## Related

- [Tumor immunology and checkpoint inhibitors](https://durgical.com/en/immunology/tumor-immunology-and-checkpoint-inhibitors/)
- [Monoclonal antibodies and biologics: naming and targets](https://durgical.com/en/immunology/monoclonal-antibodies-and-biologics-naming-and-targets/)
- [T-cell activation: two signals and superantigens](https://durgical.com/en/immunology/t-cell-activation-two-signals-and-superantigens/)
- [CD8⁺ cytotoxic T cell](https://durgical.com/en/immunology/cd8-cytotoxic-t-cell/)
- [Interleukin-6](https://durgical.com/en/immunology/interleukin-6/)
- [Immune tolerance and how autoimmunity begins](https://durgical.com/en/immunology/immune-tolerance-and-how-autoimmunity-begins/)
- [Regulatory T cell (Treg, FOXP3)](https://durgical.com/en/immunology/regulatory-t-cell/)

## Related conditions

- [Multiple myeloma](https://durgical.com/en/conditions/multiple-myeloma/)
- [Lung cancer](https://durgical.com/en/conditions/lung-cancer/)

## In Pharmacology

- [Tocilizumab](https://durgical.com/en/pharmacology/tocilizumab/)

[← All of immunology](https://durgical.com/en/immunology/)

Educational content on the immune system; not a treatment or individual vaccination guide and no substitute for a health professional's advice. No doses are given.

Sources: [Immunotherapy to Treat Cancer](https://www.cancer.gov/about-cancer/treatment/types/immunotherapy) (National Cancer Institute (NCI), 2026); [Immune Checkpoint Inhibitors](https://www.cancer.gov/about-cancer/treatment/types/immunotherapy/checkpoint-inhibitors) (National Cancer Institute (NCI), 2026); [CAR T Cells: Engineering Patients’ Immune Cells to Treat Their Cancers](https://www.cancer.gov/about-cancer/treatment/research/car-t-cells) (National Cancer Institute (NCI), 2026); [Tocilizumab Injection: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a611004.html) (U.S. National Library of Medicine (MedlinePlus), 2026).

## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake

Representative model, for educational purposes only.

---
Source: https://durgical.com/en/immunology/cancer-immunotherapy-checkpoint-inhibitors-car-t-and-vaccines/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/immunology/cancer-immunotherapy-checkpoint-inhibitors-car-t-and-vaccines/