{"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","non-hodgkin-lymphoma","dlbcl"],"sections":[],"technologies":[],"targets":[],"drugs":["inotuzumab-ozogamicin"],"companies":[],"institutions":[],"pathways":[],"terms":["flow-cytometry","antigen-escape"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":["Lymphoma: CD22 is expressed on most B-cell non-Hodgkin lymphomas and recycles rapidly between the surface and the endosome, which suits conjugate delivery, but the licensed conjugate is in acute lymphoblastic leukaemia rather than in lymphoma. In lymphoma its main use is as a second address after CD19-directed treatment has failed, and the limiting factor is surface density rather than presence."],"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":"dlbcl","kind":"cancer","name":"Diffuse large B-cell lymphoma","route":"/cancers/dlbcl/"},{"id":"non-hodgkin-lymphoma","kind":"cancer","name":"Non-Hodgkin lymphoma (all types)","route":"/cancers/non-hodgkin-lymphoma/"},{"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/"}]}}