How it is administered

Vemurafenib is taken by mouth as a tablet. The usual dose is 960 mg (four 240 mg tablets) taken twice daily, about 12 hours apart. It can be taken with or without food. Tablets should be swallowed whole and not crushed or chewed. If a dose is missed, it can be taken up to 4 hours before the next scheduled dose. If vomiting occurs after taking a dose, do not take an extra dose; just take the next dose as scheduled.

How it works

Vemurafenib is a targeted therapy that works by blocking certain proteins (kinases) involved in the growth and survival of cancer cells. Specifically, it inhibits mutated forms of the BRAF protein, especially the BRAF V600E mutation, which can cause cells to grow uncontrollably. By blocking this abnormal signaling, vemurafenib helps to slow or stop the growth of cancer cells.

In blood cancers, vemurafenib is FDA-approved for Erdheim-Chester Disease (ECD) with a BRAF V600 mutation. It may also be used in other cancers with similar mutations. The medication is not effective in cancers that do not have the BRAF V600 mutation, and it may actually promote tumor growth in those cases. Therefore, genetic testing is required before starting treatment.

Who Should take it

Vemurafenib is indicated for patients with unresectable or metastatic melanoma and for those with Erdheim-Chester Disease (ECD), but only if their cancer cells have a BRAF V600 mutation, as confirmed by an FDA-approved test.

For blood cancers, its primary use is in Erdheim-Chester Disease with the BRAF V600 mutation. It is not recommended for patients whose tumors do not have this specific mutation. Before starting vemurafenib, your doctor will order a test to check for the BRAF V600 mutation in your cancer cells.

Who should not take it

Vemurafenib should not be used in patients whose cancer does not have the BRAF V600 mutation, as it may not work and could even promote tumor growth in these cases. It should also be avoided in patients with known hypersensitivity to vemurafenib or any of its ingredients.

Caution is advised in patients with a history of severe skin reactions, heart rhythm problems (QT prolongation), liver problems, or those who are pregnant or breastfeeding. Women of childbearing age should use effective contraception during treatment and for 2 weeks after the last dose, as vemurafenib can harm an unborn baby.

Commonly used with

Vemurafenib is sometimes used in combination with other cancer therapies, but for blood cancers like Erdheim-Chester Disease, it is typically used alone. In melanoma, it may be combined with other targeted therapies or immunotherapies, but caution is needed due to increased risk of side effects, especially liver toxicity when combined with ipilimumab.

Always discuss with your doctor if you are taking or planning to take other medications, as vemurafenib can interact with other drugs.

Commonly tested with

Vemurafenib has been tested in combination with other cancer drugs, including immunotherapies like ipilimumab, but this combination has shown increased risk of liver toxicity and is not routinely recommended. It has also been studied with other targeted therapies in melanoma.

For blood cancers, especially Erdheim-Chester Disease, vemurafenib is generally studied as a single agent. Your doctor may monitor your blood counts and organ function regularly during treatment.