CD33 CD33 molecule
ENSG00000105383 · protein coding · Open Targets profile
Sialic-acid-binding immunoglobulin-like lectin (Siglec) that plays a role in mediating cell-cell interactions and in maintaining immune cells in a resting state (PubMed:10611343, PubMed:11320212, PubMed:15597323). Preferentially recognizes and binds alpha-2,3- and more avidly alpha-2,6-linked sialic acid-bearing glycans (PubMed:7718872). Upon engagement of ligands such as C1q or syalylated glycoproteins, two immunoreceptor tyrosine-based inhibitory motifs (ITIMs) located in CD33 cytoplasmic tail are phosphorylated by Src-like kinases such as LCK (PubMed:10887109, PubMed:28325905). These phosphorylations provide docking sites for the recruitment and activation of protein-tyrosine phosphatases PTPN6/SHP-1 and PTPN11/SHP- 2 (PubMed:10206955, PubMed:10556798, PubMed:10887109). In turn, these phosphatases regulate downstream pathways through dephosphorylation of signaling molecules (PubMed:10206955, PubMed:10887109). One of the repressive effect of CD33 on monocyte activation requires phosphoinositide 3-kinase/PI3K (PubMed:15597323). {ECO:0000269|PubMed:10206955, ECO:0000269|PubMed:10556798, ECO:0000269|PubMed:10611343, ECO:0000269|PubMed:10887109, ECO:0000269|PubMed:11320212, ECO:0000269|PubMed:15597323, ECO:0000269|PubMed:28325905, ECO:0000269|PubMed:7718872}.
Each band is a group of drugs. It runs from the kind of drug on the left to the furthest stage that drug has reached in any disease on the right. Thicker bands mean more drugs.
Approved bands are highlighted. Withdrawn means the drug was pulled from the market or from development. A combined phase counts as the later one (Phase 1/2 is shown as Phase 2). Hover a band for the drug names. Source: Open Targets Platform, fetched live.
Each row is a cancer, strongest overall evidence first. The two dots show how strong the inherited (germline) and tumour-mutation (somatic) evidence is; the line between them is the gap.
Scores run from 0 (no evidence) to 1 (strongest). A missing dot at 0 means Open Targets holds no evidence of that kind. Source: Open Targets Platform, fetched live.
Tractability
- Small molecule
- Structure with Ligand
- Antibody
- Advanced Clinical, UniProt loc high conf, GO CC high conf, UniProt SigP or TMHMM, Human Protein Atlas loc
- PROTAC
- Database Ubiquitination, Half-life Data
- Other modalities
- Approved Drug
gnomAD loss of function constraint: o/e 0.7973499894142151 (upper bound 1.1136000156402588). Low values mean loss of function is poorly tolerated, a safety flag for inhibition.
Who runs trials of these drugs
Principal investigators and study chairs on 41 registry trials, updated in the last three years, of the most advanced drugs against CD33 (lintuzumab, gemtuzumab), ranked by Phase 2+ trials. Live from ClinicalTrials.gov.
- Christoph RölligTechnische Universität Dresden, Medical Faculty Carl Gustav Carus · 2 of 2 trials Phase 2+
- Juliette LAMBERTVersailles Hospital · 2 of 2 trials Phase 2+
- Brenda GibsonRoyal Hospital for Sick Children · 1 of 1 trials Phase 2+
- Celalettin UstunAlliance for Clinical Trials in Oncology · 1 of 1 trials Phase 2+
- Chezi GanzelShaare Zedek Medical Center · 1 of 1 trials Phase 2+
- Fanco LocatelliDept. of Pediatric Hematology Oncology - Bambino Gesù Children's Hospital Rome · 1 of 1 trials Phase 2+
- Farhad Ravandi-KashaniM.D. Anderson Cancer Center · 1 of 1 trials Phase 2+
- Gertjan KaspersPediatric Oncologist · 1 of 1 trials Phase 2+
- Giovanni MartinelliUniversity of Bologna · 1 of 1 trials Phase 2+
- Hiroto InabaSt. Jude Children's Research Hospital · 1 of 1 trials Phase 2+
- Jayastu SenapatiM.D. Anderson Cancer Center · 1 of 1 trials Phase 2+
- Jerald P RadichSWOG Cancer Research Network · 1 of 1 trials Phase 2+
- John ReaganBrown University Oncology Research Group (BrUOG) · 1 of 1 trials Phase 2+
- Maro OhanianM.D. Anderson Cancer Center · 1 of 1 trials Phase 2+
- Mary-Elizabeth PercivalFred Hutch/University of Washington Cancer Consortium · 1 of 1 trials Phase 2+
Registry trials of lintuzumab, gemtuzumab updated in the last three years, counted by the country group of their listed sites. A trial with sites in several groups counts in each; 31 of 39 have all sites in one country.
Site counts are not patients per country, and trials registered only outside ClinicalTrials.gov are not covered. Where sites are is a fact about the record, not a judgement of its quality. Europe is the EU and EEA, the UK and Switzerland. 2 trials list no sites and are left out. Source: ClinicalTrials.gov, fetched live.
23 trials of drugs against CD33 were stopped early; 5 give no reason
Terminated, withdrawn and suspended interventional trials of lintuzumab, gemtuzumab, oncolysin m, AVE-9633, newest update first, live from ClinicalTrials.gov. Each reason is quoted exactly as the registry gives it; we do not sort reasons into safety, efficacy or business. Dates are the last registry update. Showing the 23 most recent of 23.
- withdrawn · 2026-09-23 · M.D. Anderson Cancer Center · matched by the registry's drug synonyms“PI requested”
- suspended · 2026-09-09 · National Cancer Institute (NCI) · matched by the registry's drug synonyms“Drug Supply Issues”
- suspended · 2026-08-24 · National Cancer Institute (NCI) · matched by the registry's drug synonyms“Drug Supply Issues”
- terminated · 2026-06-25 · Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins · matched by the registry's drug synonyms“Upon analysis of the first 7 participants accrued, it was determined that this combination treatment is not efficacious as treatment for patients with relapsed or refractory AML”
- terminated · 2025-07-29 · Vor Biopharma · matched by the registry's drug synonyms“Lack of Funding”
- terminated · 2023-11-18 · Jonsson Comprehensive Cancer Center · Gemtuzumab Ozogamicin“slow accrual”
- withdrawn · 2023-07-20 · Actinium Pharmaceuticals · Lintuzumab-Ac225“study postponed”
- terminated · 2023-03-10 · Weill Medical College of Cornell University · Gemtuzumab Ozogamicin“Dose limiting toxicities.”
- withdrawn · 2023-02-02 · Rush University Medical Center · matched by the registry's drug synonyms“The P.I deceased.”
- terminated · 2022-07-01 · University Hospital Heidelberg · Gemtuzumab Ozogamicin 147, Gemtuzumab Ozogamicin 1“Study turned out no longer feasible. End of Recruitment: 25.5.2022”
- terminated · 2022-06-15 · Emory University · Gemtuzumab ozogamicin“Due to unforeseen circumstances, the study team was limited in enrolling patients on this trial; thus, it was terminated.”
- terminated · 2022-03-08 · Actinium Pharmaceuticals · Lintuzumab AC 225“Poor recruitment”
- withdrawn · 2019-03-08 · Joseph Jurcic · Ac-Lintuzumab“Due to difficulty in finalizing the contract”
- terminated · 2018-10-31 · M.D. Anderson Cancer Center · matched by the registry's drug synonymsNo reason given
- withdrawn · 2018-07-02 · Wake Forest University Health Sciences · gemtuzumab ozogamicinNo reason given
- terminated · 2017-06-01 · Fred Hutchinson Cancer Center · gemtuzumab ozogamicinNo reason given
- terminated · 2017-05-10 · Alison Walker · lintuzumab“Drug no longer being supplied by sponsor”
- terminated · 2016-01-15 · University of Pittsburgh · Gemtuzumab ozogamicin“due to new safety information”
- terminated · 2015-10-12 · UNC Lineberger Comprehensive Cancer Center · gemtuzumab ozogamicin“funding unavailable”
- terminated · 2015-04-22 · New York Medical College · Gemtuzumab Ozogamicin“PI left institution”
- terminated · 2015-02-04 · Merck Sharp & Dohme LLC · Gemtuzumab ozogamicinNo reason given
- withdrawn · 2012-07-11 · European Organisation for Research and Treatment of Cancer - EORTC · lintuzumabNo reason given
- terminated · 2009-05-14 · Sanofi · matched by the registry's drug synonyms“due to absence of evidence of clinical activity up to toxic doses”
Paediatric incentives and obligations for CD33's drugs
For lintuzumab, gemtuzumab, oncolysin m, AVE-9633: what EMA and FDA publish about paediatric plans, orphan status and pediatric approvals, and how many registered studies take children. Each line is a yes, no or not published fact from the record linked under it; none of it is a forecast.
- FDA pediatric target list: yes · CD33 is on the list. Membership alone neither requires nor waives a pediatric study.Rule: Target is on FDA's Pediatric Molecular Target List (relevant targets). Source: FDA Pediatric Molecular Target List (Listed as February 2026 on the FDA Pediatric Oncology page; the file served is 9.7.22_the_relevant_molecular_target_list.xlsx, whose Summary of Changes sheet is headed 'SEPTEMBER 2022 UPDATE' (footnote date 2022-09-01)), 2026-11-11
- EU paediatric investigation plan: no · No EMA paediatric investigation plan decision names lintuzumab, gemtuzumab, oncolysin m, ave-9633Rule: An EMA PIP decision (agreement, modification or waiver) lists the drug as its active substance, exact name. Source: EMA data download (dated snapshot), 2026-11-11
- EU orphan designation: yes · EU/3/09/627 withdrawn 30 Apr 2009: Treatment of acute myeloid leukaemia; EU/3/09/626 withdrawn 29 Apr 2009: Treatment of myelodysplastic syndromesRule: An EU orphan designation lists the drug as its active substance (exact name) or belongs to a medicine that does; withdrawn and expired designations are listed with their status. Source: EMA data download (dated snapshot), 2026-11-11
- Authorised in the EU: no · EMA lists no centrally authorised medicine of lintuzumab, gemtuzumab, oncolysin m, ave-9633Rule: An EMA medicine record lists the drug as its active substance or INN, exact name; national-only authorisations are not in this file. Source: EMA data download (dated snapshot), 2026-11-11
- FDA orphan designation: not published · FDA's orphan designation database turns away automated requests, so this app does not read it; search it by hand at the linkRule: Would be: an FDA orphan designation names the drug. Source: FDA orphan designations search
- FDA pediatric oncology approval: yes · Gemtuzumab ozogamicin [Mylotarg], 16 Jun 2020: Treatment of newly-diagnosed CD33-positive acute myeloid leukemia in adults and pediatric patients 1 month and older; Gemtuzumab ozogamicin [Mylotarg], 1 Sept 2017: Treatment of relapsed or refractory CD33-positive acute myeloid leukemia in adults and pediatric patients 2 years and older.Rule: FDA's Pediatric Oncology Drug Approvals table names the drug. Source: FDA Pediatric Oncology Drug Approvals (content current as of 2026-03-03), 2026-11-11
- Registered studies open to children: yes · 39 interventional studies of lintuzumab, gemtuzumab, oncolysin m, ave-9633 include patients under 18; 9 are recruiting, not yet recruiting or activeRule: The registry's age group includes Child (birth to 17 years), which also counts studies that set no minimum age. Source: ClinicalTrials.gov search, 2026-11-11
Rare pediatric disease voucher. FDA, content current as of 29 Apr 2026: “As of February 3, 2026, enactment of the Consolidated Appropriations Act, 2026, the rare pediatric disease PRV program will sunset after September 30, 2029. FDA may not award any PRVs under this program after September 30, 2029.” Voucher sale prices are not shown here; they appear only as company-reported news. FDA: Rare Pediatric Disease Designation and Priority Review Voucher Programs
All 5 drugs and clinical candidates as a table
Each drug, stage and indication links to its Open Targets record, where the trials and approvals behind it are listed. Salt forms (for example a mesylate) are listed as Open Targets records them, as separate entries.