{"entity":{"id":"cd22-expression","kind":"biomarker","name":"CD22 expression (CD22-positive)","aka":["CD22-positive","CD22+","CD22 expression","CD22 positive ALL"],"tldr":"CD22 is a second B-cell antigen, kept even when CD19 is lost. Inotuzumab ozogamicin is labelled for CD22-positive acute lymphoblastic leukaemia.","summary":"CD22 is measured by flow cytometry on blasts; more than 90 percent of B-ALL is CD22-positive. Inotuzumab ozogamicin (Besponsa) is a CD22-directed antibody-drug conjugate labelled for relapsed or refractory CD22-positive B-cell precursor ALL in adults and children aged one and over. CD22-directed CAR-T cells are in trials for CD19-negative relapse after blinatumomab or CD19 CAR-T.","asOf":"2026-09-23","links":[{"label":"Besponsa prescribing information (DailyMed)","url":"https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=cc7014b1-c775-411d-b374-8113248b4077"}],"tags":["biomarker","surface-antigen"],"related":["cd19-expression"],"cancers":["all-leukemia","all-paediatric-relapsed"],"sections":[],"technologies":[],"targets":[],"drugs":["inotuzumab-ozogamicin"],"companies":[],"institutions":[],"pathways":[],"terms":["flow-cytometry","antigen-escape"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"target":"cd22","measurement":"ihc-score","scoringRule":{"text":"CD22 detected on leukaemia blasts by flow cytometry; the label states CD22-positive without a percentage.","quote":"BESPONSA is a CD22-directed antibody and cytotoxic drug conjugate","source":"https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=cc7014b1-c775-411d-b374-8113248b4077","sourceLabel":"Besponsa prescribing information"},"thresholds":[{"value":"CD22-positive","drugId":"inotuzumab-ozogamicin","cancerId":"all-leukemia","regulator":"FDA","source":"https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=cc7014b1-c775-411d-b374-8113248b4077","status":"current","note":"Besponsa indication: relapsed or refractory CD22-positive B-cell precursor acute lymphoblastic leukemia in adults and pediatric patients 1 year and older."}],"tests":[],"assays":[],"companionDiagnostics":[],"forPatient":"If your leukaemia is CD22-positive, inotuzumab ozogamicin is an on-label option when the disease has come back or not responded, and it remains usable if CD19 has been lost after blinatumomab or CAR-T. Liver toxicity, especially before a transplant, is the main thing your team will weigh."},"route":"/biomarkers/cd22-expression/","neighbours":{"biomarker":[{"id":"cd19-expression","kind":"biomarker","name":"CD19 expression (CD19-positive)","route":"/biomarkers/cd19-expression/"},{"id":"cd20-expression","kind":"biomarker","name":"CD20 expression (CD20-positive)","route":"/biomarkers/cd20-expression/"}],"cancer":[{"id":"all-leukemia","kind":"cancer","name":"Acute lymphoblastic leukaemia","route":"/cancers/all-leukemia/"},{"id":"all-paediatric-relapsed","kind":"cancer","name":"Relapsed and refractory acute lymphoblastic leukaemia in children","route":"/cancers/all-paediatric-relapsed/"}],"drug":[{"id":"inotuzumab-ozogamicin","kind":"drug","name":"Inotuzumab ozogamicin","route":"/drugs/inotuzumab-ozogamicin/"}],"term":[{"id":"antigen-escape","kind":"term","name":"Antigen escape (antigen loss, lineage switch)","route":"/terms/antigen-escape/"},{"id":"flow-cytometry","kind":"term","name":"Flow cytometry (immunophenotyping)","route":"/terms/flow-cytometry/"}],"target":[{"id":"cd22","kind":"target","name":"CD22","route":"/targets/cd22/"}]}}