belzutifan: prescribing and clinical use
Focused clinical detail for use alongside current product information, local policy and patient-specific assessment.
belzutifan: clinical details
Prescribing considerations
- Initiation and supervision by a cancer specialist.
- Assess concomitant medicines for CYP3A4 substrate interactions and inhibition of CYP2C19 or UGT2B17.
- Verify pregnancy status where relevant and counsel patients who could conceive or cause pregnancy about embryo-fetal risk and contraception.
- Give the patient alert card and recommend smoking cessation because of hypoxia risk.
- Use particular caution where clinically significant anaemia or hypoxia is present or develops.
- Dual UGT2B17 and CYP2C19 poor metabolisers may have substantially increased exposure and require close observation.
- Severe hepatic impairment has not been studied.
Contraindications and cautions
- Hypersensitivity to belzutifan or any excipient.
Monitoring
- Haemoglobin before treatment and periodically thereafter, with closer monitoring early in treatment.
- Oxygen saturation by pulse oximetry before and during treatment, with closer monitoring early in treatment.
- Clinical assessment for fatigue, dyspnoea, dizziness, hypoxia and anaemia.
- Pregnancy testing before treatment where applicable.
- Review adherence, interactions and continued suitability of treatment.
Clinical pharmacology
Belzutifan inhibits HIF-2 alpha and reduces transcription of genes involved in angiogenesis, proliferation and tumour growth. It is principally metabolised by UGT2B17 and CYP2C19, with a lesser CYP3A4 contribution, and induces CYP3A4 and CYP2B6 in vitro.
Formulation and product differences
- The selected product is a blue, oval, film-coated oral tablet marked “177”.
belzutifan preparations and strengths
Tablet
Route: Oral
Strengths: 40 mg
belzutifan interactions
The cancer team and pharmacist should review all prescribed, over-the-counter and herbal products.
Hormonal contraceptives
Belzutifan can reduce their effectiveness and may increase breakthrough bleeding. Suitable non-hormonal or additional barrier contraception is required.
Sensitive CYP3A4 substrates
Belzutifan can lower their concentrations and potentially cause treatment failure; avoid combinations where a small reduction would be clinically important.
UGT2B17 inhibitors
These may increase belzutifan exposure and the likelihood or severity of anaemia and hypoxia.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.