Big pharmas are already starting BRAF/MEK combo for BRAF V600E mutation melanoma. In order of progress: GSK, Roche/Daiichi Sankyo, NVS/ARRY. AZN has both BRAF and MEK (from ARRY) inhibitors as well, probably will start combo.
I wouldn't buy GSK for this alone. I do have GSK along with PFE, NVS, NVO among big pharmas. As of smaller biotech, ARRY has two MEK inhibitors. Other with MEK inhibitors are RDEA/Bayer, Takeda, Serono.
Roche/Daiichi Sankyo BRAF has showed, earlier result holds up very well in later stage trials.