ipilimumab
Yervoy (ipilimumab) is a CTLA-4 checkpoint inhibitor from Bristol-Myers Squibb. By releasing a key brake on T-cell activation it helped establish cancer immunotherapy, and is used in advanced melanoma, alone or with nivolumab.
This page is based on FDA prescribing information and the EMA medicine record for ipilimumab, cross-checked with DailyMed and the National Cancer Institute dictionary; the mechanism is explained in plain language, and analogies are used only where they stay accurate.
How it works
Explains what the medicine does in the body, not dosing, side effects, or safety.
An analogy
Before T cells can attack, they need a green light in a lymph node checkpoint. CTLA-4 is a red light raised at exactly that moment, telling them to stand down. Ipilimumab covers the red light, so more T cells get their green light, multiply and march out to hunt the tumour.
In simple terms
T cells are activated in lymph nodes, but a receptor called CTLA-4 naturally limits how strongly they respond. Some cancers take advantage of this brake. Ipilimumab blocks CTLA-4, so T cells activate more vigorously and in greater numbers. The enlarged immune army can then recognise and attack melanoma cells, producing responses that can last long after treatment ends.
In depth
Ipilimumab is a fully human IgG1 monoclonal antibody that binds CTLA-4 and blocks its interaction with the ligands B7-1 (CD80) and B7-2 (CD86). This prevents CTLA-4-mediated inhibition of T-cell costimulation through CD28, lowering the threshold for T-cell activation and depleting regulatory T cells in some settings. Its activity in metastatic melanoma established immune checkpoint blockade as a cancer treatment pillar, and combining it with PD-1 inhibitors deepens responses at the cost of higher immune-related toxicity.
See it in motion
A schematic animation of the mechanism — simplified for clarity, not drawn to scale.
How CTLA-4 checkpoint inhibitors release the brake on T cells
- T cells are activated in lymph nodes, but a receptor called CTLA-4 naturally limits how strongly they respond.
- Ipilimumab blocks CTLA-4, so T cells activate more vigorously and in greater numbers.
- This prevents CTLA-4-mediated inhibition of T-cell costimulation through CD28, lowering the threshold for T-cell activation and depleting regulatory T cells in some settings.
- The enlarged immune army can then recognise and attack melanoma cells, producing responses that can last long after treatment ends.
Target: Cytotoxic T-lymphocyte antigen 4 (CTLA-4)
A receptor that puts a brake on T-cell activation early in the immune response; tumours benefit from that brake, and blocking it amplifies T-cell priming against cancer.
Approved uses
Approved uses differ by country and change over time. Always follow your local prescribing information.
Approved uses in United States
FDA- Treatment of unresectable or metastatic melanoma in adults and children 12 years and older, as a single agent or in combination with nivolumab
- Adjuvant treatment of adults with cutaneous melanoma with pathologic involvement of regional lymph nodes of more than 1 mm who have undergone complete resection, including total lymphadenectomy
Approved uses in European Union
EMA- As monotherapy or in combination with nivolumab, for advanced (unresectable or metastatic) melanoma in adults and adolescents 12 years of age and older
Official sources
The statements on this page trace back to these records.
- Yervoy (ipilimumab) — Summary of product characteristics and package leaflet, English version
European Medicines Agency
- DailyMed: Yervoy (ipilimumab) label
DailyMed, U.S. National Library of Medicine
- U.S. Food and Drug Administration: ipilimumab prescribing information
U.S. Food and Drug Administration
- National Cancer Institute: ipilimumab
National Cancer Institute
This page explains how the medicine works — it isn’t the patient leaflet. For anything that applies to you, read the leaflet that came with your medicine or ask your pharmacist.
MedUnfold provides educational content and is not medical advice. Always follow your local prescribing information and healthcare professional.