Summary
Drugs blocking inhibitory receptors such as PD-1 release T cells to attack tumours.
In depth
PD-1 and CTLA-4 normally restrain T cells; tumours exploit them. Antibodies like pembrolizumab and ipilimumab release the brakes, giving durable responses in melanoma and others, with side effects resembling autoimmunity. Allison and Honjo won the 2018 Nobel Prize.
Responses can be dramatic but only in a subset of patients; immune-related adverse events include colitis and thyroiditis. Biomarkers include PD-L1 and tumour mutational burden.
Key idea: therapy unleashes existing immune responses.
James Allison (CTLA-4) and Tasuku Honjo (PD-1) received the 2018 Nobel Prize. Ipilimumab, approved in 2011, was the first checkpoint inhibitor, and anti-PD-1 and PD-L1 agents (nivolumab, pembrolizumab, atezolizumab) followed. Responses can be long-lasting in melanoma, lung cancer, kidney cancer and others, with some patients living for years. Tumours with many mutations and high PD-L1 respond better, and microsatellite-unstable tumours respond strongly.
Side effects are immune-related adverse events: colitis, rash, hepatitis, thyroiditis and pneumonitis, because the brakes on self-reactivity are released. Many patients do not respond, driving research into combinations and biomarkers.
Frequently asked questions
What is Immune Checkpoint Therapy?
Drugs blocking inhibitory receptors such as PD-1 release T cells to attack tumours.
Which area of biology covers Immune Checkpoint Therapy, and how advanced is it?
Immune Checkpoint Therapy is one of the 52 topics in Immunology & Disease. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Transplant Rejection, Antibodies, Monoclonal Antibodies.
Why does Immune Checkpoint Therapy matter?
Treatment targets the immune system, not the tumour, and reshaped cancer therapy.
Can you give an example of Immune Checkpoint Therapy?
Some advanced melanoma patients are in long-term remission.
What should I learn before Immune Checkpoint Therapy?
Work through the Beginner topics in Immunology & Disease first, such as Immune System, Viruses, Innate Immunity, then return to Immune Checkpoint Therapy. Advanced topics assume the Intermediate vocabulary.
What topics are related to Immune Checkpoint Therapy?
The closest topics to Immune Checkpoint Therapy are Transplant Rejection, Antibodies, Monoclonal Antibodies, CAR-T Cell Therapy. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Immune Checkpoint Therapy?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Immune Checkpoint Therapy. To practise the whole of Immunology & Disease, use the Immunology & Disease quiz.
How is Immune Checkpoint Therapy different from Transplant Rejection?
Immune Checkpoint Therapy: Drugs blocking inhibitory receptors such as PD-1 release T cells to attack tumours. Transplant Rejection: Recipient immune cells recognise donor MHC as foreign, requiring matching and immunosuppression. Read both side by side and note what each one explains.
How should I study Immune Checkpoint Therapy step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Transplant Rejection and explain the difference aloud. Finally, take the Immunology & Disease quiz and come back to this page for any question you miss.