CD33 expression (target of gemtuzumab ozogamicin)
Deterministic view of the source YAML entity. Clinical authority remains with the cited source IDs and reviewer sign-off state.
| ID | BIO-CD33-EXPRESSION |
|---|---|
| Type | Biomarker |
| Aliases | CD33 expressionЕкспресія CD33 (мішень гемтузумабу озогаміцину) |
| Status | reviewed 2026-04-29 | pending_clinical_signoff |
| Diseases | None declared |
| Sources | SRC-ALFA-0701-CASTAIGNE-2012 SRC-NCCN-AML-2025 |
Biomarker Facts
| Biomarker type | protein_expression_ihc |
|---|---|
| Measurement | MethodFlow cytometry on BM/PB blasts (anti-CD33) Unitscategorical (positive ≥20% blasts | negative); semi-quantitative MFI |
| Related biomarkers | None declared |
Notes
CD33 (Siglec-3) is the target of gemtuzumab ozogamicin (GO; anti-CD33 calicheamicin ADC). CD33+ status (≥20% of blasts) is the diagnostic standard for GO eligibility — confirmed at AML diagnostic flow panel. Cross-disease relevance: - **AML** (~85-90%): CD33+ on most myeloblasts — eligibility gate for fractionated GO add-on to 7+3 induction (ALFA-0701: 2-yr EFS 41% vs 17%; benefit driven by CBF / favorable + intermediate cytogenetics, no benefit in adverse-risk / TP53m). Also for emerging CD33 CAR-T, BiTEs (e.g. AMG-330). - **APL**: CD33+ universally; GO active as relapsed-APL salvage when ATO/ATRA-refractory. - **MDS / CMML high-blast**: subset CD33+; off-label GO occasional use. - **Pediatric AML**: COG-AAML0531 confirms GO benefit in favorable-risk peds AML (similar EFS gain). Quantitative MFI matters: low CD33 density predicts inferior GO response in CBF-AML. Hepatic VOD/SOS dose-related risk (boxed warning). `ihc_no_variant` skip reason — protein expression target, not variant.
Used By
No reverse references found in the YAML corpus.