Combination of a PD-1 antagonist and a RAF inhibitor for treating cancer

1. A method for the delay of progression or treatment of cancer in a subject, comprising administering to the subject in need thereof a therapeutically effective amount of a PD-1 antagonist in combination with a therapeutically effective amount of a RAF inhibitor,

wherein the cancer is associated with a B-Raf mutation or a K-Ras mutation, wherein the cancer is a lung cancer or a colon cancer;

wherein the PD-1 antagonist is an antibody or an antigen binding fragment thereof, which specifically binds to human PD-1 and which comprises a heavy chain variable region (Vh) and a light chain variable region (Vk), wherein the Vh comprises complementarity determining region (CDR)1, CDR2, and CDR3 comprising SEQ ID NOs: 31, 32, and 33, respectively; and the Vk comprises CDR1, CDR2, CDR3 comprising SEQ ID NO: 34, 35, and 36, respectively; and

wherein the RAF inhibitor is a compound of Formula (I),

or a stereoisomer thereof, or a pharmaceutically acceptable salt thereof, wherein:

X is selected from CH 2 and O;

R 8 , R 9 , R 10 and R 11 , which may be the same or different, are each selected from the group consisting of hydrogen, halogen, alkyl, alkenyl, cycloalkyl, aryl, heterocyclyl, heteroaryl, alkynyl, —NR 13 R 14 , —OR 13 , —COR 13 , —CO 2 R 13 , —CONR 13 R 14 , —C(═NR 13 )NR 14 R 15 , —NR 13 COR 14 , —NR 13 CONR 14 R 15 , —NR 13 C O 2 R 14 , —SO 2 R 13 , —SO 2 aryl, —NR 13 S O 2 NR 14 R 15 , and —NR 13 SO 2 R 14 , wherein the alkyl, alkenyl, alkynyl, cycloalkyl, heteroaryl, aryl, and heterocyclyl are each optionally substituted with at least one substituent R 16 , or (R 8 and R 9 ), and/or (R 9 and R 10 ), and/or (R 10 and R 11 ) together with the ring to which they are attached, form a fused ring selected from the group consisting of heterocyclyl and heteroaryl rings optionally substituted with at least one substituent R 16 ;

R 13 , R 14 and R 15 , which may be the same or different, are each selected from the group consisting of H, haloalkyl, alkyl, alkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl, and heteroaryl; or (R 13 and R 14 ), and/or (R 14 and R 15 ) together with the atom(s) to which they are attached, each form a ring selected from the group consisting of heterocyclyl and heteroaryl rings optionally substituted with at least one substituent R 16 ;

R 16 is selected from the group consisting of halogen, haloalkyl, alkyl, alkenyl, cycloalkyl, aryl, heteroaryl, heterocyclyl, alkynyl, oxo, —CN, —OR′, —NR′R″, —COR′, —CO 2 R′, —CONR′R″, —C(═NR′)NR″R′″, —NR′COR″, —NR′CONR′R″, —NR′CO 2 R″, —SO 2 R′, —SO 2 aryl, —NR′S O 2 NR″R′″, —NR′O 2 R″, and —NR′SO 2 aryl, wherein R′, R″, and R′″ are independently selected from the group consisting of H, haloalkyl, alkyl, alkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl, and heteroaryl, or (R′ and R″), and/or (R″ and R′″) together with the atoms to which they are attached, form a ring selected from the group consisting of heterocyclyl and heteroaryl rings.

2. The method of claim 1 , wherein the heavy chain variable region (Vh) comprises SEQ ID NO: 24 and the light chain variable region (Vk) comprises SEQ ID NO: 26.

3. The method of claim 1 , wherein the antibody comprises a IgG4 heavy chain constant domain comprising any of SEQ ID NOs:83-88.

4. The method of claim 1 , wherein the antibody fragment is a Fv fragment, F(ab), Fab′, or F(ab′).

5. The method according to claim 1 , wherein the antibody comprises an IgG4 heavy chain constant domain comprising SEQ ID NO: 88, and wherein the heavy chain variable region (Vh) and the light chain variable region (Vk) comprise SEQ ID NO: 24 and SEQ ID NO: 26, respectively.

6. The method of claim 1 , wherein R 8 , R 9 , R 10 , and R 11 in Formula (I), which may be the same or different, are each independently selected from the group consisting of alkyl, hydrogen, haloalkyl, halogen, hydroxy, —CN, —Oalkyl, —Ohaloalkyl, and aryl.

7. The method of claim 1 , wherein the RAF inhibitor is a compound of Formula (I),

or a stereoisomer thereof, or a pharmaceutically acceptable salt thereof, wherein:

X is selected from the group consisting of CH 2 and O;

R 8 , R 9 , R 10 and R 11 , which may be the same or different, are each selected from the group consisting of hydrogen, halogen, alkyl, —CN, cycloalkyl, aryl, heterocyclyl, —OR 13 , and —CONR 13 R 14 , wherein the alkyl, and aryl are each optionally substituted with at least one substituent R 16 , or (R 8 and R 9 ), and/or (R 9 and R 10 ), and/or (R 10 and R 11 ) together with the ring to which they are attached, form a fused ring selected from cycloalkyl;

R 13 and R 14 , which may be the same or different, are each selected from the group

consisting of H, alkyl, and haloalkyl;

R 16 is selected from halogen, haloalkyl, and alkyl.

8. The method of claim 1 , wherein the RAF inhibitor is a compound of Formula (I),

or a stereoisomer thereof, or a pharmaceutically acceptable salt thereof, wherein:

X is selected from the group consisting of CH 2 and O;

R 8 is selected from the group consisting of H, F, Cl, and Br;

R 9 is selected from the group consisting of H, F, Cl, Br, and C 1-6 alkyl;

R 10 is selected from H, F, Cl, Br, OH, —CN, C 1-6 alkyl, CF 3 , phenyl, OC 1-6 alkyl, OC 1-6 haloalkyl, and —CONR 13 R 14 , wherein R 13 and R 14 may be the same or different, are each selected from the group consisting of H and C 1-6 alkyl;

R 11 is selected from the group consisting of H, F, Cl, Br, and CF 3 ;

or (R 9 and R 10 ) together with the ring to which they are attached, form a fused ring selected from C 5-6 cycloalkyl.

9. The method of claim 1 , wherein the cancer is associated with a B-Raf mutation.

10. The method of claim 1 , wherein the cancer is associated with a K-Ras mutation.

11. The method of claim 1 , wherein the PD-1 antagonist and the RAF inhibitor are administered simultaneously.

12. The method of claim 1 , wherein the RAF inhibitor is administered orally at a dose of 5-80 mg QD.

13. The method of claim 1 , wherein the PD-1 antagonist is administered parenterally at a dose of 0.5-10 mg/kg QW, or Q2W, or Q3W, or Q4W.

14. The method of claim 1 , wherein the PD-1 antagonist is administered at a dose of 0.5-10 mg/kg QW or Q2W or Q3W, and the RAF inhibitor is administered at a dose of 5-80 mg QD.

15. The method of claim 1 , wherein the PD-1 antagonist is administered at a dose of 0.5-10 mg/kg QW or Q2W or Q3W, and the RAF inhibitor is administered at a dose of 10-30 mg QD.

16. The method of claim 1 , wherein the RAF inhibitor is a compound of Formula (II),

or a pharmaceutically acceptable salt thereof.

17. The method of claim 1 , wherein the PD-1 antagonist and the RAF inhibitor are administered sequentially.

18. The method of claim 1 , wherein the subject is a human.

19. The method of claim 16 , wherein the subject is a human.

20. A method for the delay of progression or treatment of cancer in a subject, comprising administering to the subject in need thereof a therapeutically effective amount of a PD-1 antagonist in combination with a therapeutically effective amount of a RAF inhibitor;

wherein the cancer is associated with a B-Raf mutation or a K-Ras mutation, wherein the

cancer is a lung cancer or a colon cancer; and

wherein the PD-1 antagonist is an antibody which comprises a heavy chain variable region (Vh), a light chain variable region (Vk), and a IgG4 heavy chain effector or constant domain comprising SEQ ID NO: 88, wherein the heavy chain variable region (Vh) and the light chain variable region (Vk) comprise SEQ ID NO: 24 and SEQ ID NO: 26, respectively; and

wherein the RAF inhibitor is the compound of Formula (IIIa)

21. The method of claim 20 , wherein the subject is a human.