Vemurafenib
Kinase inhibitors (targeted oncology)
Kinase inhibitors (targeted oncology)High alert
An error with this medicine can cause serious harm: double checks and protocols are used.
An oral inhibitor of mutant BRAF V600E for melanoma that carries this mutation; it causes photosensitivity and new skin squamous cell cancers.
Also called: PLX4032
Quick facts
- Group
- Kinase inhibitors (targeted oncology)
- Target
- BRAF kinase with the V600E mutation
- Used for
- Unresectable or metastatic melanoma
- Key effects
- Joint pain · Rash · Photosensitivity and sunburn
- Monitor
- BRAF V600 mutation test before starting · Liver tests
- ATC
- L01EC01
No doses: the clinician sets them by the current guideline.
Mechanism of action
The crystal shows vemurafenib in the ATP site of the human BRAF V600E kinase domain.
Many melanomas carry a BRAF V600 mutation that keeps the RAF–MEK–ERK pathway switched on. Vemurafenib, whose name comes from «V600E», inhibits the mutant BRAF kinase (also V600K) and shuts down this pathway, so the melanoma cells stop growing. Melanomas without the mutation do not respond. It may be combined with a MEK inhibitor (cobimetinib), as is done with other BRAF inhibitors to delay resistance.
- BRAF V600E keeps RAF–MEK–ERK switched on
- Vemurafenib blocks mutant BRAF
- MAPK signalling stops; melanoma cells stop growing
- No effect without the BRAF V600 mutation
Indications
- Unresectable or metastatic melanoma with a BRAF V600E mutation, confirmed by testing. Melanoma →
- Erdheim-Chester disease with a BRAF V600 mutation.
Adverse effects
Common
- Joint pain
- Rash, thickened skin (hyperkeratosis), skin papillomas
- Photosensitivity and sunburn
- Hair loss
- Fatigue, headache, fever
- Hand-foot skin reaction
Contraindications
- Melanoma without a BRAF V600 mutation (no benefit, possible harm)
- Caution: long QT, heart failure, low potassium, magnesium or calcium
Key interactions
- Tizanidine and other narrow-margin CYP1A2 substrates
- Vemurafenib raises their levels; tizanidine is avoided.
- Strong CYP3A4 inducers and inhibitors, St John's wort
- Change vemurafenib levels; avoided.
- Other QT-prolonging drugs
- Add to QT prolongation.
What is monitored
- BRAF V600 mutation test before starting
- Full skin examination before starting and regularly during and after treatment
- ECG and electrolytes
- Liver tests
Administration and safety
- Oral; swallowed whole at about the same time each day.
- Check the name carefully: kinase inhibitors with similar «-tinib» names are not interchangeable.
- Taken twice daily about twelve hours apart, with or without food; a vomited dose is not repeated.
Pregnancy and breastfeeding
May harm the fetus; contraception is used during treatment and for a short time after, and breastfeeding is avoided.
Nursing care
- Look at the skin at every visit and report new growths or sores.
- Check that ECG and electrolyte results are up to date.
- Teaching: avoid sun exposure, wear protective clothing, lip balm and broad-spectrum sunscreen; report palpitations, fainting or yellow skin.
Pharmacokinetics
- Absorption
- Oral, with or without food.
- Metabolism
- Substrate of CYP3A4; substrate and inhibitor of P-glycoprotein; it raises levels of CYP1A2 substrates.
- Half-life
- Long, about two to three days.
Test yourself
Think of the answer, then tap the question to see it.
Which test is required before vemurafenib?
A test confirming a BRAF V600E mutation in the melanoma.
Which new skin lesion appears in some patients on vemurafenib?
Cutaneous squamous cell carcinoma.
Which muscle relaxant is avoided with vemurafenib, and why?
Tizanidine, because vemurafenib raises the levels of CYP1A2 substrates.
Connections
← Back to the class: Kinase inhibitors (targeted oncology)
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Vemurafenib: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2018); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).
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Representative model, for educational purposes only.