C-RAF mutants that confer resistance to RAF inhibitors

1. A method of treating a subject having cancer, the cancer comprising a mutant C-RAF polypeptide, the method comprising:

(a) extracting nucleic acid from a sample of cells of the subject;

(b) assaying at least a portion of a nucleic acid molecule encoding a C-RAF polypeptide from the sample to identify the presence of a mutation in a nucleic acid molecule encoding a mutant C-RAF polypeptide having a 257S>P mutation as compared to a wild type C-RAF polypeptide of SEQ ID NO: 2; and

(c) administering an effective amount of a RAF inhibitor and an effective amount of a MEK inhibitor to the subject having the cancer comprising the mutant C-RAF polypeptide, the sample having the nucleic acid molecule that includes nucleotides that alter the amino acid residue at position 257 of the encoded mutant C-RAF polypeptide.

2. The method according to claim 1 , wherein the RAF inhibitor is selected from the group consisting of RAF265, sorafenib, SB590885, PLX 4720, PLX4032, GDC-0879, ZM 336372 and (S)-methyl 1-(4-(3-(5-chloro-2-fluoro-3-(methylsulfonamido)phenyl)-1-isopropyl-1H-pyrazol-4-yl)pyrimidin-2-ylamino)propan-2-ylcarbamate.

3. The method according to claim 1 , wherein the MEK inhibitor is selected from the group consisting of CI-1040/PD 184352, AZD6244, PD318088, PD98059, PD334581, RDEA1 19, 6-Methoxy-7-(3-morpholin-4-yl-propoxy)-4-(4-phenoxy-phenylamino)-quinoline-3-carbonitrile and 4-[3-Chloro-4-(1-methyl-1H-imidazol-2-ylsulfanyl)-phenylamino]-6-methoxy-7-(3-morpholin-4-yl-propoxy)-quinoline-3-carbonitrile.

4. The method according to claim 1 , wherein the cancer is selected from the group consisting of melanoma, breast cancer, colorectal cancers, glioma, lung cancer, ovarian cancer, sarcoma and thyroid cancer.

5. The method according to claim 1 , wherein the subject has cancer cells comprising a mutation in B-RAF at 600V>E.