A Japanese case of melanoma of unknown origin with a rare BRAF V600R 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 BRAF or BRAF changes. There are no reports of BRAF in Japanese patients with melanoma. The third most common BRAF mutation is BRAF. In this case, we detected the BRAF 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.