A compound selected from the group consisting of: N-((4,6-dimethyl-2-oxo-1,2-dihydropyridin-3-yl)methyl)-1-isopropyl-3-methyl-6-(pyridin-3-yl)-1H-pyrazolo[3,4-b]pyridine-4-carboxamide; N-((4,6-dimethyl-2-oxo-1,2-dihydropyridin-3-yl)methyl)-1-isopropyl-3-methyl-6-phenyl-1H-pyrazolo[3,4-b]pyridine-4-carboxamide; N-((4,6-dimethyl-2-oxo-1,2-dihydropyridin-3-yl)methyl)-6-(4-((dimethylamino)methyl)phenyl)-1-isopropyl-3-methyl-1H-pyrazolo[3,4-b]pyridine-4-carboxamide; N-((4,6-dimethyl-2-oxo-1,2-dihydropyridin-3-yl)methyl)-6-(4-fluorophenyl)-1-isopropyl-3-methyl-1H-pyrazolo[3,4-b]pyridine-4-carboxamide; 1-cyclopropyl- N -[(4,6-dimethyl-2-oxo-1,2-dihydro-3-pyridinyl)methyl]-3-methyl-6-[6-(4-methyl-1-piperazinyl)-3-pyridinyl]-1 H -pyrazolo[3,4-b]pyridine-4-carboxamide; 1-cyclopropyl- N -[(4,6-dimethyl-2-oxo-1,2-dihydro-3-pyridinyl)methyl]-3-methyl-6-[6-(4-morpholinyl)-3-pyridinyl]-1 H -pyrazolo[3,4- b]pyridine-4-carboxamide; N-((4-benzyl-6-methyl-2-oxo-1,2-dihydropyridin-3-yl)methyl)-1-isopropyl-3-methyl-1H-pyrazolo[3,4-b]pyridine-4-carboxamide; 6-cyclopropyl- N -[(4-cyclopropyl-6-methyl-2-oxo-1,2-dihydro-3-pyridinyl)methyl]-3-methyl-1-(1-methylethyl)-1 H -pyrazolo[3,4- b]pyridine-4-carboxamide; 6-cyclopropyl-3-methyl-1-(1-methylethyl)- N -{[6-methyl-4-(1-methylethyl)-2-oxo-1,2-dihydro-3-pyridinyl]methyl}-1 H -pyrazolo[3,4- b]pyridine-4-carboxamide; 6-cyclopropyl-3-methyl-1-(1-methylethyl)- N -[(6-methyl-2-oxo-4-propyl-1,2-dihydro-3-pyridinyl)methyl]-1 H -pyrazolo[3,4- b]pyridine-4-carboxamide; 6-cyclopropyl-3-methyl-1-(1-methylethyl)- N -{[6-methyl-2-oxo-4-(phenylmethyl)-1,2-dihydro-3-pyridinyl]methyl}-1 H -pyrazolo[3,4- b]pyridine-4-carboxamide; 1-isopropyl-N-((6-methyl-2-oxo-4-propyl-1,2-dihydropyridin-3-yl)methyl)-6-phenyl-1H-pyrazolo[3,4-b]pyridine-4-carboxamide; 1-cyclopropyl- N -[(4,6-dimethyl-2-oxo-1,2-dihydro-3-pyridinyl)methyl]-3-methyl-6-(2-methyl-5-pyrimidinyl)-1 H -pyrazolo[3,4- b]pyridine-4-carboxamide; 1-cyclopropyl- N -[(4,6-dimethyl-2-oxo-1,2-dihydro-3-pyridinyl)methyl]-3-methyl-6-[4-(methyloxy)phenyl]-1 H -pyrazolo[3,4- b]pyridine-4-carboxamide; 6-cyclopropyl-1-(1,1-dimethylethyl)-3-methyl- N -[(6-methyl-2-oxo-4-propyl-1,2-dihydro-3-pyridinyl)methyl]-1 H -pyrazolo[3,4- b]pyridine-4-carboxamide; 1,6-dicyclopropyl-3-methyl- N -[(6-methyl-2-oxo-4-propyl-1,2-dihydro-3-pyridinyl)methyl]-1 H -pyrazolo[3,4- b]pyridine-4-carboxamide; 1,6-dicyclopropyl- N -[(4,6-dimethyl-2-oxo-1,2-dihydro-3-pyridinyl)methyl]-3-methyl-1 H -pyrazolo[3,4- b]pyridine-4-carboxamide; 6-(cyclopropylamino)-N-((4,6-dimethyl-2-oxo-1,2-dihydropyridin-3-yl)methyl)-1-isopropyl-3-methyl-1H-pyrazolo[3,4-b]pyridine-4-carboxamide; and N-((4-benzyl-6-methyl-2-oxo-1,2-dihydropyridin-3-yl)methyl)-1-isopropyl-1H-pyrazolo[3,4-b]pyridine-4-carboxamide; or a pharmaceutically acceptable salt thereof. N-((4,6-dimethyl-2-oxo-1,2-dihydropyridin-3-yl)methyl)-1-isopropyl-3-methyl-6-(pyridin-3-yl)-1H-pyrazolo[3,4-b]pyridine-4-carboxamide; N-((4,6-dimethyl-2-oxo-1,2-dihydropyridin-3-yl)methyl)-1-isopropyl-3-methyl-6-phenyl-1H-pyrazolo[3,4-b]pyridine-4-carboxamide; N-((4,6-dimethyl-2-oxo-1,2-dihydropyridin-3-yl)methyl)-6-(4-((dimethylamino)methyl)phenyl)-1-isopropyl-3-methyl-1H-pyrazolo[3,4-b]pyridine-4-carboxamide; N-((4,6-dimethyl-2-oxo-1,2-dihydropyridin-3-yl)methyl)-6-(4-fluorophenyl)-1-isopropyl-3-methyl-1H-pyrazolo[3,4-b]pyridine-4-carboxamide; 1-cyclopropyl- N -[(4,6-dimethyl-2-oxo-1,2-dihydro-3-pyridinyl)methyl]-3-methyl-6-[6-(4-methyl-1-piperazinyl)-3-pyridinyl]-1 H -pyrazolo[3,4-b]pyridine-4-carboxamide; 1-cyclopropyl- N -[(4,6-dimethyl-2-oxo-1,2-dihydro-3-pyridinyl)methyl]-3-methyl-6-[6-(4-morpholinyl)-3-pyridinyl]-1 H -pyrazolo[3,4- b]pyridine-4-carboxamide; N-((4-benzyl-6-methyl-2-oxo-1,2-dihydropyridin-3-yl)methyl)-1-isopropyl-3-methyl-1H-pyrazolo[3,4-b]pyridine-4-carboxamide; 6-cyclopropyl- N -[(4-cyclopropyl-6-methyl-2-oxo-1,2-dihydro-3-pyridinyl)methyl]-3-methyl-1-(1-methylethyl)-1 H -pyrazolo[3,4- b]pyridine-4-carboxamide; 6-cyclopropyl-3-methyl-1-(1-methylethyl)- N -{[6-methyl-4-(1-methylethyl)-2-oxo-1,2-dihydro-3-pyridinyl]methyl}-1 H -pyrazolo[3,4- b]pyridine-4-carboxamide; 6-cyclopropyl-3-methyl-1-(1-methylethyl)- N -[(6-methyl-2-oxo-4-propyl-1,2-dihydro-3-pyridinyl)methyl]-1 H -pyrazolo[3,4- b]pyridine-4-carboxamide; 6-cyclopropyl-3-methyl-1-(1-methylethyl)- N -{[6-methyl-2-oxo-4-(phenylmethyl)-1,2-dihydro-3-pyridinyl]methyl}-1 H -pyrazolo[3,4- b]pyridine-4-carboxamide; 1-isopropyl-N-((6-methyl-2-oxo-4-propyl-1,2-dihydropyridin-3-yl)methyl)-6-phenyl-1H-pyrazolo[3,4-b]pyridine-4-carboxamide; 1-cyclopropyl- N -[(4,6-dimethyl-2-oxo-1,2-dihydro-3-pyridinyl)methyl]-3-methyl-6-(2-methyl-5-pyrimidinyl)-1 H -pyrazolo[3,4- b]pyridine-4-carboxamide; 1-cyclopropyl- N -[(4,6-dimethyl-2-oxo-1,2-dihydro-3-pyridinyl)methyl]-3-methyl-6-[4-(methyloxy)phenyl]-1 H -pyrazolo[3,4- b]pyridine-4-carboxamide; 6-cyclopropyl-1-(1,1-dimethylethyl)-3-methyl- N -[(6-methyl-2-oxo-4-propyl-1,2-dihydro-3-pyridinyl)methyl]-1 H -pyrazolo[3,4- b]pyridine-4-carboxamide; 1,6-dicyclopropyl-3-methyl- N -[(6-methyl-2-oxo-4-propyl-1,2-dihydro-3-pyridinyl)methyl]-1 H -pyrazolo[3,4- b]pyridine-4-carboxamide; 1,6-dicyclopropyl- N -[(4,6-dimethyl-2-oxo-1,2-dihydro-3-pyridinyl)methyl]-3-methyl-1 H -pyrazolo[3,4- b]pyridine-4-carboxamide; 6-(cyclopropylamino)-N-((4,6-dimethyl-2-oxo-1,2-dihydropyridin-3-yl)methyl)-1-isopropyl-3-methyl-1H-pyrazolo[3,4-b]pyridine-4-carboxamide; and N-((4-benzyl-6-methyl-2-oxo-1,2-dihydropyridin-3-yl)methyl)-1-isopropyl-1H-pyrazolo[3,4-b]pyridine-4-carboxamide;