{"entity":{"id":"dll3-expression","kind":"biomarker","name":"DLL3 expression","aka":["DLL3","DLL3-positive","delta-like ligand 3 expression","DLL3 IHC"],"tldr":"DLL3 sits on the surface of about 85 percent of small-cell lung cancers and almost no normal adult tissue. Tarlatamab is given without a DLL3 test.","summary":"Tarlatamab (Imdelltra) is a DLL3 x CD3 bispecific labelled for extensive-stage small-cell lung cancer after platinum chemotherapy; the DeLLphi trials enrolled without DLL3 selection and the label names DLL3 only as the target. DLL3-directed ADCs, radioligands and CAR-T cells in trials likewise do not gate on expression, and a DLL3 PET tracer is under study.","asOf":"2026-09-23","links":[{"label":"IMDELLTRA prescribing information (DailyMed)","url":"https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=1e7b6163-5d83-42ea-82c9-cf7620cdc782"}],"tags":["biomarker","surface-antigen","no-threshold"],"related":["b7-h3-expression"],"cancers":["sclc","extensive-stage-sclc","prostate-nepc"],"sections":[],"technologies":[],"targets":[],"drugs":["tarlatamab"],"companies":[],"institutions":[],"pathways":[],"terms":["sclc-molecular-subtypes"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"target":"dll3","measurement":"ihc-score","scoringRule":{"text":"The label names the antigen in the drug's description but does not require it to be measured before treatment; no approval threshold exists for this readout.","quote":"IMDELLTRA is a bispecific delta-like ligand 3 (DLL3)-directed CD3 T-cell engager","source":"https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=1e7b6163-5d83-42ea-82c9-cf7620cdc782","sourceLabel":"IMDELLTRA prescribing information (DailyMed)"},"thresholds":[],"tests":[],"assays":[],"companionDiagnostics":[],"forPatient":"Tarlatamab does not require a DLL3 test; the target is present in most small-cell lung cancers. Treatment starts in hospital because of the risk of cytokine release in the first cycle."},"route":"/biomarkers/dll3-expression/","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":"prostate-nepc","kind":"cancer","name":"Neuroendocrine and small-cell prostate cancer","route":"/cancers/prostate-nepc/"},{"id":"sclc","kind":"cancer","name":"Small-cell lung cancer","route":"/cancers/sclc/"}],"drug":[{"id":"tarlatamab","kind":"drug","name":"Tarlatamab","route":"/drugs/tarlatamab/"}],"term":[{"id":"sclc-molecular-subtypes","kind":"term","name":"Small-cell lung cancer transcription-factor subtypes (SCLC-A, SCLC-N, SCLC-P, SCLC-I) and SLFN11","route":"/terms/sclc-molecular-subtypes/"}],"target":[{"id":"dll3","kind":"target","name":"DLL3","route":"/targets/dll3/"}]}}