The first immune brake ever targeted for cancer; releasing it won a Nobel Prize and cures a fraction of melanomas.
CTLA-4 is a checkpoint on activated and regulatory T cells that competes with CD28 for B7 ligands during T-cell priming; antibodies against it broaden the T-cell response and, through Fc effector function, deplete regulatory T cells inside tumours. Ipilimumab (2011) was the first checkpoint inhibitor, and the concept later shared a Nobel Prize. Combined with nivolumab it yields 10-year survival near 50 percent in advanced melanoma (CheckMate 067), and the pair is used in RCC, MSI-high colorectal cancer, HCC and mesothelioma. The cost is frequent immune-related toxicity such as colitis and hypophysitis, and because it acts on immune cells there is no tumour biomarker to select patients. Fc-engineered and probody CTLA-4 antibodies aim to reduce toxicity. Releasing this brake was the first proof that the immune system can cure some cancers.
In plain words · The first immune brake ever targeted for cancer; releasing it won a Nobel Prize and cures a fraction of melanomas.
Backbone ribbon from PDB 5TRU. RCSB PDB 5TRU. The ribbon widens where the chain is folded into a regular pattern and narrows where it is a loose loop.
The first immune brake ever targeted for cancer; releasing it won a Nobel Prize and cures a fraction of melanomas.
Competes with CD28 for B7 ligands during T-cell priming; also depletes regulatory T cells via Fc effector function.
10 products aim at CTLA-4: antibodies, bispecific antibodies and other agents. Checkpoint drugs are antibodies that cover one side of an immune ‘stand down’ handshake so T cells stay active.
Immune or microenvironment target: the record's class is immune checkpoint. HPA CTLA4: RNA tissue enriched (lymphoid tissue 35 nTPM); blood lineage lineage enriched (T-cells 43 nTPM); no normal tissue stained high. Distribution: 5 cancer families in the corpus carry a prevalence row, label threshold or catalogue link for it (Skin cancer (all types), Renal cell carcinoma, Colorectal cancer, Hepatocellular carcinoma, Mesothelioma); approvals of single-target medicines aimed at it also list Lung cancer (all types), not counted; Open Targets associates it with 6 specific cancer types at or above 0.5 (autoimmune lymphoproliferative syndrome due to CTLA4 haploinsufficiency, non-small cell lung carcinoma, melanoma, hepatocellular carcinoma, renal cell carcinoma, basal cell carcinoma). (Rule 1 of scripts/fetch-target-specificity.ts.)
Sources: Human Protein Atlas CTLA4 tissue; UniProt P16410; Open Targets ENSG00000163599 associations
First described 1988. Earliest sequence paper UniProt cites for the protein: Dariavach et al, Eur. J. Immunol, 1988, "Human Ig superfamily CTLA-4 gene: chromosomal localization and identity of protein sequence between murine and human CTLA-4 cytoplasmic domains". Source.
Competes with CD28 for B7 ligands during T-cell priming; also depletes regulatory T cells via Fc effector function.
RNA: tissue enriched (lymphoid tissue 35 nTPM), detected in many normal tissues. Blood: lineage enriched (T-cells 43 nTPM).
No normal tissue stained high.
No cancer sample stained medium or high.
HPA CTLA4 tissue · HPA CTLA4 pathology · HPA protein class: CD markers, FDA approved drug targets
Human Protein Atlas version 25.1, antibody staining at reliability approved, enhanced or supported; used under CC BY-SA 3.0. Staining counts are patients per level in the atlas cohort, not population prevalence.
ADG126 is an experimental monoclonal antibody from Adagene in phase 2 trials for hepatocellular carcinoma, aimed at CTLA-4.
BA3071 is an experimental monoclonal antibody from BioAtla in phase 2 trials for non-small-cell lung cancer and melanoma, aimed at CTLA-4.
BCD-217 is an experimental investigational agent whose form is not stated in the registry from Biocad in phase 3 trials for melanoma, aimed at PD-1 and CTLA-4.
Botensilimab is an experimental monoclonal antibody from Agenus in phase 2 trials for colorectal cancer, aimed at CTLA-4.
A Chinese two-armed antibody that blocks PD-1 and CTLA-4 together, approved in China for cervical cancer and extending survival even in PD-L1-negative tumours.
Gotistobart is an experimental monoclonal antibody from OncoC4 in phase 3 trials for non-small-cell lung cancer, melanoma and head and neck squamous cell carcinoma, aimed at CTLA-4.
Ipilimumab was the first checkpoint inhibitor (2011), and proved the immune system could be unleashed against cancer.
JK08 is an experimental fusion protein or cytokine from Salubris Biotherapeutics in phase 2 trials for melanoma, colorectal cancer and non-small-cell lung cancer, aimed at CTLA-4.
Lorigerlimab is an experimental bispecific antibody from MacroGenics in phase 2 trials for ovarian cancer, vulvar cancer and cervical cancer, aimed at PD-1 and CTLA-4.
Tremelimumab is AstraZeneca's CTLA-4 antibody, given as a single priming dose with durvalumab and chemotherapy in lung and liver cancer.
For patients with advanced melanoma, immunotherapy offers a realistic chance of long-term survival and probably cure, and the ten-year data show that patients who are alive and progression-free at three years rarely die of melanoma afterwards. Nivolumab plus ipilimumab gives the best long-term results but at a high price in serious side effects; nivolumab alone or nivolumab plus relatlimab are alternatives for patients at lower risk or with autoimmune concerns. The trial is also a caution about surrogate endpoints: the survival plateau took years to become visible.
The first credible response signal in microsatellite stable colorectal cancer, and the reason the field's attention has moved to Fc engineering and to excluding patients with active liver metastases, in whom responses are rare.
Patients with melanoma that has spread to palpable lymph nodes should now be offered immunotherapy before rather than only after surgery: two cycles of low-dose ipilimumab with nivolumab, then surgery, with the pathology result deciding whether any more treatment is needed. Most patients respond well and are spared a year of adjuvant therapy. Serious side effects are more common than with nivolumab alone, mostly endocrine, and the approach requires close coordination between oncologists, surgeons and pathologists.
For colon cancer that is mismatch-repair deficient (about 10-15% of colon cancers, more in older patients), a single short course of immunotherapy before surgery is now a reasonable standard and is far more effective than chemotherapy, which has little effect in this subtype. It requires testing every colon cancer for mismatch repair at diagnosis, before surgery. Whether some patients can safely skip surgery, as in dMMR rectal cancer, is the next question.
Combination checkpoint blockade became a first-line standard for mismatch repair-deficient metastatic colorectal cancer in 2025; the later all-lines comparison against nivolumab alone showed the CTLA-4 antibody adds to the PD-1 antibody, the first phase 3 to prove that in this disease.
This trial supplied the randomised proof that was missing for TIL therapy and showed academic centres can run cell-therapy phase 3 trials without industry. It supports TIL as a standard option after checkpoint inhibitor failure in melanoma and underpinned reimbursement in the Netherlands. The comparator, ipilimumab, is itself only modestly effective in this setting, and overall survival did not differ significantly.
Checkpoint inhibitors are now given to hundreds of thousands of patients a year, many in community clinics and emergency departments, so a common, explicit playbook for their autoimmune side effects saves lives. The guideline standardised when to stop, when to give steroids and when to escalate, and made multidisciplinary toxicity teams routine. It does not remove the judgement needed for rare events or for patients whose cancer is responding.
One pathway page on OnCo cites this paper by its DOI; this record gives the citation a page of its own so a reader can follow it without leaving OnCo. Read the abstract above alongside the citing page listed under Related; the record was created automatically from the Europe PMC entry and its figures have not been checked by hand.
Query for this target: (TITLE:"CTLA-4" OR ABSTRACT:"CTLA-4" OR TITLE:"CTLA4" OR ABSTRACT:"CTLA4") AND (cancer OR tumor OR tumour OR oncology OR carcinoma OR lymphoma OR leukemia OR leukaemia OR myeloma OR sarcoma OR melanoma OR glioma). Results are unfiltered search hits about CTLA-4, not a curated reading list.
Shares BCD-217, CheckMate 9DW, Autophagy promotes immune evasion of pancreatic cancer by degrading MHC-I, Paul Baas and the tag checkpoint.
Shares VISTA, Pardoll 2012: the blockade of immune checkpoints in cancer immunotherapy, Istituto Nazionale Tumori IRCCS Fondazione G. Pascale, Hallmark: avoiding immune destruction and the tag checkpoint.
Shares Durvalumab with or without tremelimumab for patients with metastatic pancreatic ductal adenocarcinoma: a phase 2 randomized clinical trial, HIMALAYA, Nivolumab plus Ipilimumab in Lung Cancer with a High Tumor Mutational Burden, Ribas and Wolchok 2018: cancer immunotherapy using checkpoint blockade and the tag checkpoint.
Shares T-cell exhaustion, Immune checkpoint, Checkpoint (two meanings), Cold tumours and the immunosuppressive microenvironment and the tag checkpoint.
Shares Tumour microenvironment (TME), Checkpoint (two meanings), Cold tumours and the immunosuppressive microenvironment and the tag checkpoint.
Shares Autophagy promotes immune evasion of pancreatic cancer by degrading MHC-I, Phase 2 trial of single agent ipilimumab (anti-CTLA-4) for locally advanced or metastatic pancreatic adenocarcinoma, Durvalumab with or without tremelimumab for patients with metastatic pancreatic ductal adenocarcinoma: a phase 2 randomized clinical trial, Targeting CXCL12 from FAP-expressing carcinoma-associated fibroblasts synergizes with anti-PD-L1 immunotherapy in pancreatic cancer.
Shares CheckMate 9DW, Paul Baas, CheckMate 648, Michael A. Postow.
Shares Michael A. Postow, F. Stephen Hodi, Jedd D. Wolchok, Leach, Krummel and Allison: releasing the CTLA-4 brake makes mice reject tumours.