vemurafenib

Vemurafenib is an oral targeted therapy approved for the treatment of melanoma that harbors the BRAF V600 mutation. It acts as a selective inhibitor of the BRAF protein kinase within the MAPK signaling pathway, preferentially blocking signaling in tumor cells with the V600E mutation and reducing cell proliferation. The drug is not effective in melanomas without BRAF V600 mutations.

Indications and use: Vemurafenib was approved for unresectable or metastatic melanoma with the BRAF V600E mutation. It has been studied and used in combination with the MEK inhibitor cobimetinib, a strategy that can improve outcomes and delay resistance compared with BRAF inhibition alone in patients with BRAF V600-mutant melanoma.

Administration and dosing: Vemurafenib is taken by mouth at a dose of 960 mg (four 240 mg tablets) twice daily until disease progression or intolerable toxicity. Dose modifications are recommended for adverse reactions, including severe skin toxicity, liver enzyme elevations, and cardiac effects. Baseline and periodic dermatologic assessment are advised because of the risk of new skin cancers; liver function tests and electrolytes should be monitored as appropriate.

Adverse effects and safety: Common adverse effects include rash, arthralgia, photosensitivity, fatigue, nausea, alopecia, pruritus, and stomatitis. Serious risks include cutaneous squamous cell carcinoma and keratoacanthoma, hepatic toxicity, and QT interval prolongation. Vemurafenib should be used in pregnancy only if clearly needed; contraception is advised for women of childbearing potential. Interactions may occur with strong CYP3A4 inhibitors or inducers, which can affect drug levels.