A Japanese case of melanoma of unknown origin with a rare BRAFV600R mutation was successfully treated with BRAF/MEK inhibitors.

Combination therapy with BRAF and MEK inhibitors (BRAF/MEKi) has shown significantly prolonged progression-free survival (PFS) and overall survival (OS) for BRAF mutated melanoma. Over 90% of the activating mutations are BRAFV600E or BRAFV600K changes. There are no reports of BRAFV600R in Japanese patients with melanoma. The third most common BRAF mutation is BRAFV600R. In this case, we detected the BRAFV600R mutation with FoundationOne CDx in a Japanese patient with melanoma.. The patient was treated with BRAF/MEKi and maintained stable disease status for 1 year. [ABSTRACT FROM AUTHOR]