Last reviewed · How we verify

Hydroxyurea (HU)

Bionoxx Inc. · Phase 3 active Small molecule

Hydroxyurea inhibits ribonucleotide reductase, reducing deoxyribonucleotide synthesis and slowing DNA replication in rapidly dividing cells.

Hydroxyurea inhibits ribonucleotide reductase, reducing deoxyribonucleotide synthesis and slowing DNA replication in rapidly dividing cells. Used for Chronic myeloid leukemia (CML), Sickle cell disease (to reduce vaso-occlusive crises), Polycythemia vera.

At a glance

Generic nameHydroxyurea (HU)
SponsorBionoxx Inc.
Drug classAntimetabolite; ribonucleotide reductase inhibitor
TargetRibonucleotide reductase
ModalitySmall molecule
Therapeutic areaOncology; Hematology
PhasePhase 3

Mechanism of action

By blocking the enzyme ribonucleotide reductase, hydroxyurea depletes the deoxyribonucleotide pool required for DNA synthesis, thereby slowing or halting cell division. In sickle cell disease, it also increases fetal hemoglobin (HbF) production, which inhibits polymerization of sickle hemoglobin and reduces hemolysis. This dual mechanism makes it useful in both oncology and hematologic disorders.

Approved indications

Common side effects

Key clinical trials

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

SourceUsed for
ClinicalTrials.govTrial enrolment, design, endpoints, results

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape: