Oxbryta

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  • Anemias

Oxbryta Generic Name & Formulations

General Description

Voxelotor 300mg, 500mg; tabs.

Pharmacological Class

Hemoglobin S polymerization inhibitor.

How Supplied

Tabs 300mg—60, 90; 500mg—90; Tabs for Oral Susp—60, 90

Generic Availability

NO

Mechanism of Action

Voxelotor is a hemoglobin S (HbS) polymerization inhibitor that binds to HbS and exhibits preferential partitioning to red blood cells. By increasing the affinity of Hb for oxygen, voxelotor demonstrates dose-dependent inhibition of HbS polymerization.

Oxbryta Indications

Indications

Sickle cell disease.

Oxbryta Dosage and Administration

Adult

Swallow tabs whole. If difficulty swallowing, tabs for oral susp may be used; disperse tabs for oral susp in room temp clear liquid (eg, water, clear soda, apple juice) before swallowing. ≥12yrs: 1500mg once daily. Severe hepatic impairment: 1000mg once daily. Avoid concomitant strong or moderate CYP3A4 inducers; if unavoidable, increase dose to 2000mg once daily (with moderate CYP3A4 inducers); 2500mg once daily (with strong CYP3A4 inducers).

Children

<4yrs: not established. Use tabs or tabs for oral susp based on the ability to swallow and body weight. Disperse tabs for oral susp in room temp clear liquid (eg, water, clear soda, apple juice) before swallowing. 4–<12yrs (10–<20kg): 600mg once daily; (20–<40kg): 900mg once daily; (≥40kg): 1500mg once daily. Severe hepatic impairment (10–<20kg): 300mg once daily; (20–<40kg): 600mg once daily; (≥40kg): 1000mg (two 500mg tabs) or 900mg (three 300mg tabs for oral susp or three 300mg tabs) once daily. Avoid concomitant strong or moderate CYP3A4 inducers; if unavoidable with moderate CYP3A4 inducers (10–<20kg): 900mg once daily; (20–<40kg): 1200mg once daily; (≥40kg): 2000mg (four 500mg tabs) or 2100mg (seven 300mg tabs for oral susp or seven 300mg tabs) once daily; if unavoidable with strong CYP3A4 inducers (10–<20kg): 900mg once daily; (20–<40kg): 1500mg once daily; (≥40kg): 2500mg (five 500mg tabs) or 2400mg (eight 300mg tabs for oral susp or eight 300mg tabs) once daily.

Oxbryta Contraindications

Not Applicable

Oxbryta Boxed Warnings

Not Applicable

Oxbryta Warnings/Precautions

Warnings/Precautions

Discontinue if hypersensitivity reactions occur; do not reinitiate. Severe hepatic impairment: reduce dose. Pregnancy. Nursing mothers: not recommended (during and for ≥2 weeks after the last dose).

Oxbryta Pharmacokinetics

Absorption

Median plasma and whole blood Tmax is 2 hours after oral administration. Mean peak concentrations in whole blood and RBCs are observed between 6 and 18 hours after oral administration. High-fat, high-calorie meal increased AUC and Cmax.

Distribution

Apparent volume of distribution: 333 L (in central compartment); 72.3 L (in plasma). Plasma protein bound: 99.8%.

Metabolism

Hepatic (CYP3A4, CYP3A5, CYP2B6, CYP2C19, CYP2C9, UGT1A1, UGT1A9). 

Elimination

Fecal (62.6%), renal (35.5%). Half-life: 38.7 hours. Apparent oral clearance: ~6.1 L/h in plasma.

Oxbryta Interactions

Interactions

May be antagonized by strong or moderate CYP3A4 inducers; if unavoidable, increase voxelotor dose. May be potentiated by strong CYP3A4 inhibitors. Avoid concomitant sensitive CYP3A4 substrates with a narrow therapeutic index; if unavoidable, consider dose reduction of the substrate. May interfere with measurement of Hb subtypes by high-performance liquid chromatography.

Oxbryta Adverse Reactions

Adverse Reactions

Headache, diarrhea, abdominal pain, nausea, rash, pyrexia, vomiting; hypersensitivity reactions (eg, DRESS).

Oxbryta Clinical Trials

See Literature

Oxbryta Note

Not Applicable

Oxbryta Patient Counseling

See Literature