{"entity":{"id":"steap1","kind":"target","name":"STEAP1","aka":[],"tldr":"STEAP1 is a protein on the surface of most prostate cancer cells, now the address for a T-cell engager in phase 3.","summary":"Six-transmembrane epithelial antigen of the prostate 1 is expressed in most prostate cancers including PSMA-low and neuroendocrine-like disease, with limited normal expression. Xaluritamig (STEAP1×CD3 XmAb 2+1) produced PSA50 in ~half of heavily pretreated mCRPC patients at target doses in phase 1 and is in two phase 3 trials (XALute post-taxane; XALience with abiraterone chemo-naive). Also an ADC target historically (vandortuzumab vedotin, discontinued).","asOf":"2026-09-06","wikipedia":"https://en.wikipedia.org/wiki/STEAP1","links":[{"label":"Wikipedia","url":"https://en.wikipedia.org/wiki/STEAP1"}],"tags":["t-cell-engager-target"],"related":[],"cancers":["prostate"],"sections":[],"technologies":[],"targets":[],"drugs":["xaluritamig"],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":["Prevalence not recorded: no peer-reviewed STEAP1 expression series with a stated denominator was found for prostate cancer; the widely repeated '>80%' figure could not be traced to a series with an n, so it has been removed."],"symbol":"STEAP1","role":[],"sources":[],"specificity":"tumour-associated","distribution":"one-type","specificityNote":"Tumour-associated overexpression: 1 cell-killing or cell-finding medicine (Xaluritamig) aim at the antigen, which HPA finds with no normal tissue stained high; the medicine relies on the tumour carrying more of it than the normal tissue it shares it with. HPA STEAP1: RNA tissue enhanced (prostate 79 nTPM); no normal tissue stained high; highest cancer staining lung cancer (1 of 11 high). Distribution: 1 cancer family in the corpus carries a prevalence row, label threshold or catalogue link for it (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 STEAP1 tissue","url":"https://www.proteinatlas.org/ENSG00000164647-STEAP1/tissue","note":"RNA tissue and blood lineage specificity, normal tissue antibody staining (version 25.1, CC BY-SA 3.0)"},{"label":"Human Protein Atlas STEAP1 pathology","url":"https://www.proteinatlas.org/ENSG00000164647-STEAP1/pathology","note":"patients per staining level per cancer type (version 25.1, CC BY-SA 3.0)"},{"label":"Open Targets ENSG00000164647 associations","url":"https://platform.opentargets.org/target/ENSG00000164647/associations","note":"cancer associations at or above 0.5 (CC0)"}],"hgnc":"HGNC:11378","ensembl":"ENSG00000164647","uniprot":"Q9UHE8","entrez":"26872","firstDescribed":1999,"firstDescribedBasis":"sequence","firstDescribedNote":"Earliest sequence paper UniProt cites for the protein: Hubert R.S. et al, Proc. Natl. Acad. Sci. U.S.A, 1999, \"STEAP: a prostate-specific cell-surface antigen highly expressed in human prostate tumors\".","firstDescribedSource":"https://pubmed.ncbi.nlm.nih.gov/10588738/","biology":"STEAP1 is a metalloreductase at cell junctions, upregulated by androgen receptor signalling; its expression is partly independent of PSMA, making it complementary.","whereFound":["Prostate cancer (most cases)","Ewing sarcoma","Bladder (subset)"],"targetClass":"surface-antigen","prevalence":[]},"route":"/targets/steap1/","neighbours":{"cancer":[{"id":"prostate","kind":"cancer","name":"Prostate cancer","route":"/cancers/prostate/"}],"drug":[{"id":"xaluritamig","kind":"drug","name":"Xaluritamig","route":"/drugs/xaluritamig/"}],"trial":[{"id":"xalute","kind":"trial","name":"XALute","route":"/trials/xalute/"}],"person":[{"id":"owen-witte","kind":"person","name":"Owen N. Witte","route":"/people/owen-witte/"}]}}