Combination therapy using a chemokine receptor 2 (CCR2) antagonist and a PD-1/PD-L1 inhibitor

A method of treating colorectal cancer in a mammal, said method comprising administering a therapeutically effective amount of a CCR2 chemokine receptor antagonist and a therapeutically effective amount of a PD-1 and/or PD-L1 inhibitor, wherein said CCR2 chemokine receptor antagonist is a compound of Formula (Ia4)

• or a pharmaceutically acceptable salt thereof;
• wherein
• the subscripts m and n are each independently 1;
• R3 is selected from the group consisting of C1-8 alkyl and C3-8 cycloalkyl;
• R4 is selected from the group consisting of H and C1-8 alkyl;
• the subscript p is 1 or 2;
• each Rx is independently selected from the group consisting of halogen, —Rc, —ORa, —O—X1—ORa, and —X1—ORa, wherein each X1 is a C1-4 alkylene;
• each Ra is selected from hydrogen, C1-8 alkyl, and C1-8 haloalkyl;
• each Rc is independently selected from the group consisting of C1-8 alkyl and C1-8 haloalkyl;
• the subscript q is 1 or 2;
• each Rz is independently selected from the group consisting of halogen, —Ri, —CO2Rg, and tetrazole;
• wherein each R9 is selected from hydrogen, C1-8 alkyl, and C1-8 haloalkyl;
• each Ri is independently selected from the group consisting of C1-8 alkyl, and C1-8 haloalkyl.