CD22
CD22 is a B-cell surface protein and the docking site for the leukaemia ADC inotuzumab ozogamicin.
CD22 is expressed on >90% of B-ALL blasts and on B-cell lymphomas. Inotuzumab ozogamicin (INO-VATE) is approved in relapsed/refractory B-ALL and is moving into frontline for older adults (ALLIANCE A041501) and children (COG AALL1732). CD22 CAR-T (including CD19/CD22 bispecific CARs) targets CD19-negative relapse. Antigen density, not just positivity, predicts CAR-T response.
- Target · the protein and the cell it sits on
- Drug · antibody, small molecule, cell or radioligand
- Effect · signal, damage or kill
In plain words · CD22 is a B-cell surface protein and the docking site for the leukaemia ADC inotuzumab ozogamicin.
- 1 · What it is
CD22 is a B-cell surface protein and the docking site for the leukaemia ADC inotuzumab ozogamicin.
- 2 · What goes wrong in cancer
Siglec-2; inhibitory co-receptor of the B-cell receptor, rapidly internalising, which suits ADC delivery.
- 3 · How drugs use it
2 products aim at CD22: antibody-drug conjugates and immunotoxins. Because it sits on the outside of the cell, it can be reached from the bloodstream: antibodies flag the cell, ADCs deliver a toxin, radioligands deliver radiation, and CAR-T or bispecifics bring a T cell.
Biology
Siglec-2; inhibitory co-receptor of the B-cell receptor, rapidly internalising, which suits ADC delivery.
- B-ALL (>90%)
- B-cell lymphomas
- Hairy cell leukaemia
How common it is, by cancer
| Cancer | Prevalence | Measure | Note | Source |
|---|---|---|---|---|
| Acute lymphoblastic leukaemia | >90% | expression on B-ALL blasts |
Approximate, population-level figures; the measure column says what was counted. Ranges show the midpoint as a bar.
Inotuzumab ozogamicin is an antibody carrying a DNA-cutting toxin to CD22 on leukaemia cells. It gets far more relapsed ALL patients into remission than chemotherapy and bridges them to transplant.
An immunotoxin for hairy cell leukaemia that produced lasting remissions in relapsed patients but was withdrawn from sale in 2023 for commercial reasons.
Latest papers
topQuery for this target: (TITLE:"CD22" OR ABSTRACT:"CD22") AND (cancer OR tumor OR tumour OR oncology OR carcinoma OR lymphoma OR leukemia OR leukaemia OR myeloma OR sarcoma OR melanoma OR glioma). Results are unfiltered search hits about CD22, not a curated reading list.