Nexavar (Sorafenib) for RAF mutation please help

I need to know how good is Nexavar (Sorafenib) at targeting RAF1 mutation, I ask this because Mom used Foundation One, have this mutation, and one of three Targeted Therapies recommended is Sorafenib, the other two being Regorafenib and Trametinib

The mutation is related to cell division pathway called the MAPK path: MAPK>RAS>RAF>MEK>CCNE1

Also, how to avoid as much as we can nausea? and if you can tell the most frequent side effects in practise and ways to avoid them