{"entity":{"id":"b7h3","kind":"target","name":"B7-H3","aka":[],"tldr":"B7-H3 is an immune checkpoint-like surface protein found on 60 to 70% of small-cell lung cancers and 80 to 90% of castration-resistant prostate cancers, with little on normal tissue. It is used as an ADC address, chiefly by ifinatamab deruxtecan, now in phase 3 in small-cell lung cancer; whether blocking its immune-dampening role adds anything beyond payload delivery is unresolved.","summary":"B7-H3 (CD276) is an immune checkpoint-like molecule broadly overexpressed in solid tumours with limited normal expression; its function is debated, inhibiting T-cell activation and promoting tumour cell migration. Expression is more homogeneous than many ADC targets, found in 60-70% of small-cell lung cancer and 80-90% of castration-resistant prostate cancer by IHC, as well as head and neck and paediatric solid tumours. Ifinatamab deruxtecan (I-DXd) has shown high response rates in small-cell lung cancer and is in phase 3. B7-H3 is also pursued with radioligands and CAR-T. Whether its immune-dampening role means antibodies against it add an immunological benefit beyond payload delivery is unresolved. The simple version is a widely present tumour surface protein now used mainly as an address for ADCs.","asOf":"2026-09-04","wikipedia":"https://en.wikipedia.org/wiki/CD276","links":[{"label":"Wikipedia","url":"https://en.wikipedia.org/wiki/CD276"}],"tags":["adc-target"],"related":["b7-h3-expression"],"cancers":["sclc","prostate"],"sections":[],"technologies":[],"targets":[],"drugs":["yl201","qlc5508","bnt324","bcb-276"],"companies":["dualitybio","myricx-bio"],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"symbol":"CD276","role":["immune-checkpoint"],"sources":[],"specificity":"tumour-associated","distribution":"few-types","specificityNote":"Tumour-associated overexpression: 5 cell-killing or cell-finding medicines (YL201, QLC5508, BNT324 and more) aim at the antigen, which HPA finds stained high in 1 normal tissue; the medicine relies on the tumour carrying more of it than the normal tissue it shares it with. HPA CD276: RNA low tissue specificity; high antibody staining in 1 normal tissue; highest cancer staining skin cancer (7 of 12 high). Distribution: 2 cancer families in the corpus carry a prevalence row, label threshold or catalogue link for it (Lung cancer (all types), Prostate cancer); Open Targets associates it with 0 specific cancer types at or above 0.5. (Rule 5 of scripts/fetch-target-specificity.ts.)","specificitySources":[{"label":"Human Protein Atlas CD276 tissue","url":"https://www.proteinatlas.org/ENSG00000103855-CD276/tissue","note":"RNA tissue and blood lineage specificity, normal tissue antibody staining (version 25.1, CC BY-SA 3.0)"},{"label":"Human Protein Atlas CD276 pathology","url":"https://www.proteinatlas.org/ENSG00000103855-CD276/pathology","note":"patients per staining level per cancer type (version 25.1, CC BY-SA 3.0)"},{"label":"Open Targets ENSG00000103855 associations","url":"https://platform.opentargets.org/target/ENSG00000103855/associations","note":"cancer associations at or above 0.5 (CC0)"}],"hgnc":"HGNC:19137","ensembl":"ENSG00000103855","uniprot":"Q5ZPR3","entrez":"80381","firstDescribed":2001,"firstDescribedBasis":"sequence","firstDescribedNote":"Earliest sequence paper UniProt cites for the protein: Chapoval A.I. et al, Nat. Immunol, 2001, \"B7-H3: a costimulatory molecule for T cell activation and IFN-gamma production\".","firstDescribedSource":"https://pubmed.ncbi.nlm.nih.gov/11224528/","biology":"Function debated: inhibits T-cell activation, promotes tumour cell migration. Expression is more homogeneous than many ADC targets.","whereFound":["Small-cell lung cancer","Prostate","Head and neck","Paediatric solid tumours"],"targetClass":"surface-antigen","prevalence":[{"cancerId":"sclc","pct":"60-70","measure":"IHC, any expression","source":"https://en.wikipedia.org/wiki/CD276"},{"cancerId":"prostate","pct":"80-90","measure":"IHC, any expression","source":"https://en.wikipedia.org/wiki/CD276","note":"Castration-resistant disease"}]},"route":"/targets/b7h3/","neighbours":{"biomarker":[{"id":"b7-h3-expression","kind":"biomarker","name":"B7-H3 (CD276) expression","route":"/biomarkers/b7-h3-expression/"}],"cancer":[{"id":"extensive-stage-sclc","kind":"cancer","name":"Extensive-stage small-cell lung cancer","route":"/cancers/extensive-stage-sclc/"},{"id":"glioblastoma","kind":"cancer","name":"Glioma & glioblastoma","route":"/cancers/glioblastoma/"},{"id":"head-and-neck","kind":"cancer","name":"Head and neck squamous cell carcinoma","route":"/cancers/head-and-neck/"},{"id":"osteosarcoma","kind":"cancer","name":"Osteosarcoma","route":"/cancers/osteosarcoma/"},{"id":"prostate","kind":"cancer","name":"Prostate cancer","route":"/cancers/prostate/"},{"id":"rhabdomyosarcoma","kind":"cancer","name":"Rhabdomyosarcoma","route":"/cancers/rhabdomyosarcoma/"},{"id":"sclc","kind":"cancer","name":"Small-cell lung cancer","route":"/cancers/sclc/"}],"drug":[{"id":"bcb-276","kind":"drug","name":"BCB-276","route":"/drugs/bcb-276/"},{"id":"bnt324","kind":"drug","name":"BNT324","route":"/drugs/bnt324/"},{"id":"ifinatamab-deruxtecan","kind":"drug","name":"Ifinatamab deruxtecan","route":"/drugs/ifinatamab-deruxtecan/"},{"id":"qlc5508","kind":"drug","name":"QLC5508","route":"/drugs/qlc5508/"},{"id":"yl201","kind":"drug","name":"YL201","route":"/drugs/yl201/"}],"company":[{"id":"aktis-oncology","kind":"company","name":"Aktis Oncology","route":"/companies/aktis-oncology/"},{"id":"dualitybio","kind":"company","name":"Duality Biotherapeutics","route":"/companies/dualitybio/"},{"id":"medilink","kind":"company","name":"MediLink Therapeutics","route":"/companies/medilink/"},{"id":"myricx-bio","kind":"company","name":"Myricx Bio","route":"/companies/myricx-bio/"}],"idea":[{"id":"idea-alpha-after-adc","kind":"idea","name":"Alpha radioligands after ADC failure","route":"/ideas/idea-alpha-after-adc/"},{"id":"idea-bio2-intraventricular-car-t","kind":"idea","name":"Deliver CAR-T cells straight into the fluid around the brain","route":"/ideas/idea-bio2-intraventricular-car-t/"},{"id":"idea-fus-plus-adc-glioma","kind":"idea","name":"Focused-ultrasound BBB opening to deliver ADCs and radioligands to glioma","route":"/ideas/idea-fus-plus-adc-glioma/"},{"id":"idea-bio2-fus-for-cell-entry","kind":"idea","name":"Open the barrier so engineered immune cells can enter the brain","route":"/ideas/idea-bio2-fus-for-cell-entry/"},{"id":"idea-bio1-antigen-mapping-at-progression","kind":"idea","name":"Re-map the tumour's surface proteins before choosing the next antibody drug","route":"/ideas/idea-bio1-antigen-mapping-at-progression/"}],"trial":[{"id":"ideate-lung02","kind":"trial","name":"IDeate-Lung02","route":"/trials/ideate-lung02/"}],"pairing":[{"id":"tarlatamab-vs-idxd-sequence","kind":"pairing","name":"Sequencing DLL3 engager and B7-H3 ADC in relapsed SCLC","route":"/pairings/tarlatamab-vs-idxd-sequence/"}],"technology":[{"id":"adc","kind":"technology","name":"Antibody-drug conjugate (ADC)","route":"/technologies/adc/"},{"id":"bispecific-adc","kind":"technology","name":"Bispecific ADC","route":"/technologies/bispecific-adc/"}],"person":[{"id":"robbie-majzner","kind":"person","name":"Robbie G. Majzner","route":"/people/robbie-majzner/"}],"term":[{"id":"checkpoint","kind":"term","name":"Checkpoint (two meanings)","route":"/terms/checkpoint/"},{"id":"overexpression","kind":"term","name":"Overexpression","route":"/terms/overexpression/"}],"pathway":[{"id":"lineage-plasticity-neuroendocrine","kind":"pathway","name":"Lineage plasticity & neuroendocrine transformation","route":"/pathways/lineage-plasticity-neuroendocrine/"}],"target":[{"id":"hhla2","kind":"target","name":"HHLA2 (B7-H7)","route":"/targets/hhla2/"}]}}