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Oxbryta (Voxelotor)
Hemoglobin S polymerization inhibitor that binds HbS 1:1 and increases oxygen affinity.
Voxelotor (Oxbryta) is a small molecule hemoglobin S polymerization inhibitor approved under accelerated approval for sickle cell disease in patients 4 years and older based on hemoglobin increase. The drug demonstrates linear pharmacokinetics with a 38.7-hour half-life, extensive hepatic metabolism via multiple CYP enzymes, and preferential distribution to red blood cells. Major risks include serious hypersensitivity reactions (contraindicated in prior hypersensitivity), significant CYP3A4 drug interactions requiring dose adjustments or avoidance, and laboratory test interference with hemoglobin subtype measurement. Continued approval is contingent on verification of clinical benefit in confirmatory trials.
At a glance
| Generic name | Voxelotor |
|---|---|
| Sponsor | Pfizer Inc. |
| Drug class | Hemoglobin S polymerization inhibitor |
| Target | Hemoglobin S (HbS) |
| Modality | Small molecule |
| Therapeutic area | Hematology |
| Phase | FDA-approved |
| Annual revenue | 250 |
Mechanism of action
Voxelotor is a hemoglobin S polymerization inhibitor that binds to HbS with a 1:1 stoichiometry and exhibits preferential partitioning to red blood cells. By increasing the affinity of hemoglobin for oxygen, voxelotor demonstrates dose-dependent inhibition of HbS polymerization. Nonclinical studies suggest that voxelotor may inhibit RBC sickling, improve RBC deformability, and reduce whole blood viscosity.
Approved indications
- Treatment of sickle cell disease (SCD) in adults
- Treatment of sickle cell disease (SCD) in pediatric patients 4 years of age and older
Common side effects
- Sickle cell anaemia with crisis
- Pyrexia
- Upper respiratory tract infection
- Malaria
- Headache
- Arthralgia
- Pain in extremity
- Abdominal pain
- Vomiting
- Cough
- Nausea
- Back pain
Drug interactions
- Strong or moderate CYP3A4 inducers
- Sensitive CYP3A4 substrates with narrow therapeutic index
Patents
| Patent | Expiry | Type |
|---|---|---|
Primary sources
Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.
| Source | Used for |
|---|---|
| FDA Orange Book | Patents + exclusivity |
| SEC EDGAR | Revenue + earnings |
Competitive intelligence
For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:
- Oxbryta CI brief — competitive landscape report
- Oxbryta updates RSS · CI watch RSS
- Pfizer Inc. portfolio CI