Summary
Hydroxyurea has reached the approved stage (maximum clinical phase 4) for at least one indication, so its use in Myelodysplastic Syndromes (MDS) would be drug repurposing rather than first-in-human development. This does not mean it is approved for Myelodysplastic Syndromes (MDS). ClinicalTrials.gov lists 8 registered trials linking Hydroxyurea to Myelodysplastic Syndromes (MDS): 1 is currently recruiting; 1 is active or not yet recruiting; 5 have completed; 1 is terminated, withdrawn, suspended or of unknown status. The most advanced is Phase 3 (NCT00005823). It plans or enrolled 2000 participants. Registration activity spans 1998 to 2024. The literature layer holds 5 publications for this pair: 5 clinical trial publications. Publication years run from 2005 to 2021. These are primary trial reports rather than syntheses, so results have not yet been pooled or graded independently.
The RepurpOS disease-intelligence file for Myelodysplastic Syndrome ranks 50 candidate therapeutics from Open Targets, ChEMBL, DGIdb and PubMed; only a minority carry direct clinical evidence, and this page covers one of those. Spontaneous remission context recorded for the condition: Essentially zero; progressive cytopaenia and transformation to AML in 30-40% of higher-risk MDS over 2-5 years; median survival low-risk MDS ~5 years, high-risk ~1 year without treatment.
Evidence table
| Evidence tier | A · Strong |
|---|---|
| Evidence score | 53.5 (trials 23.5, literature 10.0, tier 15, approved bonus 5.0) |
| Registered trials | 8 total: 1 recruiting, 1 active / not yet recruiting, 5 completed, 1 other |
| Linked publications | 5 (5 clinical trial publications) |
| Agent type | Drug (Small molecule) |
| Development stage (any indication) | Approved |
| Mechanism / class | Not recorded |
| Data sources | DGIdb |
| Linked via biomarker / target | BLM |
How the evidence score is calculated
- Each registered trial scores by status (recruiting / active / enrolling 3, completed 2.5, not yet recruiting 2, unknown 1, terminated / withdrawn / suspended 0.5) plus a phase bonus (phase 3-4 +2, phase 2 +1, phase 1 +0.5). The trial component is capped at 30.
- Each literature item scores by design (Cochrane review 5, meta-analysis 4, systematic review 3, RCT 3, clinical trial publication 2, curated reference 1.5, other PubMed record 1). The literature component is capped at 30.
- The existing evidence tier adds 15 (A / Strong), 10 (B / Moderate), 5 (C / Preliminary) or 0 (D / Anecdotal).
- Agents approved for any indication (max clinical phase 4) add 5, because an approved agent has an established safety profile that lowers the barrier to repurposing trials.
- The score ranks what has been studied, not what works. It does not read effect sizes or directions of effect.
Registered clinical trials
| NCT ID | Title | Status | Phase | Enrolment |
|---|---|---|---|---|
| NCT00005823 | Intensive Compared With Nonintensive Chemotherapy in Treating Older Patients With Acute Myeloid Leukemia or Myelodysplastic Syndrome 1998 | completed | Phase 3 | 2,000 |
| NCT02626715 | Reduced-Intensity Conditioning (RIC) and Myeloablative Conditioning (MAC) for HSCT in AML/MDS 2015 | completed | Phase 2 | 21 |
| NCT00083187 | VNP40101M in Treating Patients With Acute Myelogenous Leukemia or High-Risk Myelodysplasia 2005 | completed | Phase 2 | 230 |
| NCT02017457 | Azacytidine and Lymphocytes in Relapse of AML or MDS After Allogeneic Stem Cell Transplantation. 2013 | completed | Phase 2 | 50 |
| NCT02158858 | A Phase 1/2 Study of CPI-0610 With and Without Ruxolitinib in Patients With Hematologic and Myeloproliferative Malignancies 2014 | completed | PHASE1, PHASE2 | 336 |
| NCT06175923 | Role of BMP Pathway in MDS Progression 2024 | not yet recruiting | Not applicable | 60 |
| NCT06199557 | A Study to Investigate Treatment of HU and VPA, or 6-MP and VPA in Unfit AML/HR-MDS Patients 2024 | recruiting | PHASE1, PHASE2 | 48 |
| NCT01828619 | Study of New RIC Regimen of BuFlu in Older and/or Intolerable Patients 2013 | status unknown | Not applicable | 60 |
Published literature
- Clinical trial publication Real-Life experience with hydroxyurea in patients with sickle cell disease: Results from the prospective ESCORT-HU cohort studyde Montalembert M, Voskaridou E, Oevermann L et al. · American journal of hematology · 2021 · PMID 34224583
- Clinical trial publication Busulfan in patients with polycythemia vera or essential thrombocythemia refractory or intolerant to hydroxyureaAlvarez-Larrán A, Martínez-Avilés L, Hernández-Boluda JC et al. · Annals of hematology · 2014 · PMID 24981691
- Clinical trial publication Treatment of polycythemia vera with hydroxyurea and pipobroman: final results of a randomized trial initiated in 1980Kiladjian JJ, Chevret S, Dosquet C et al. · Journal of clinical oncology : official journal of the American Society of Clinical Oncology · 2011 · PMID 21911721
- Clinical trial publication A comparison of low-dose cytarabine and hydroxyurea with or without all-trans retinoic acid for acute myeloid leukemia and high-risk myelodysplastic syndrome in patients not considered fit for intensive treatmentBurnett AK, Milligan D, Prentice AG et al. · Cancer · 2007 · PMID 17315155
- Clinical trial publication Clinical trial of valproic acid and all-trans retinoic acid in patients with poor-risk acute myeloid leukemiaBug G, Ritter M, Wassmann B et al. · Cancer · 2005 · PMID 16294345
Mechanism and notes
No mechanism of action is recorded for this pair in the source databases.
OSMF's existing evidence tier for this pair is A (Strong), derived from the strength of the disease association recorded in DGIdb, in this case via the biomarker or target BLM. The tier describes how well the drug-disease link is documented, not how well the drug works.
Frequently asked questions
Is Hydroxyurea approved for Myelodysplastic Syndromes (MDS)?
Hydroxyurea has reached the approved stage (maximum clinical phase 4) for at least one indication, so its use in Myelodysplastic Syndromes (MDS) would be drug repurposing rather than first-in-human development. This does not mean it is approved for Myelodysplastic Syndromes (MDS). Approval status for the specific indication should always be confirmed with the relevant regulator and prescribing information.
Is Hydroxyurea in clinical trials for Myelodysplastic Syndromes (MDS)?
ClinicalTrials.gov lists 8 registered trials linking Hydroxyurea to Myelodysplastic Syndromes (MDS): 1 is currently recruiting; 1 is active or not yet recruiting; 5 have completed; 1 is terminated, withdrawn, suspended or of unknown status. The most advanced is Phase 3 (NCT00005823). It plans or enrolled 2000 participants. Registration activity spans 1998 to 2024.
What does the evidence show for Hydroxyurea in Myelodysplastic Syndromes (MDS)?
Hydroxyurea has 5 completed trials and 5 linked publications for Myelodysplastic Syndromes (MDS). Completed trials may or may not have posted results; follow the NCT links to check. OSMF's existing evidence tier for this pair is A (Strong), derived from the strength of the disease association recorded in DGIdb, in this case via the biomarker or target BLM. The tier describes how well the drug-disease link is documented, not how well the drug works.
Cite this page
Data: ClinicalTrials.gov, PubMed, Open Targets, ChEMBL, DGIdb and the OSMF therapeutic agent database. Last updated 2026-07-06. Page built 2026-10-07.