A compound which is: 2-(tert-butoxy)-2-[4-(8-fluoro-5-methyl-3,4-dihydro-2H-1-benzopyran-6-yl)-1,6-dimethyl-2-{2-[3-(morpholin-4-yl)azetidin-1-yl]pyridin-4-yl}-1H-pyrrolo[2,3-b]pyridin-5-yl]acetic acid, 2-(tert-butoxy)-2-[4-(8-fluoro-5-methyl-3,4-dihydro-2H-1,4-benzoxazin-6-yl)-1,6-dimethyl-2-[2-(1-methyl-1H-indazol-5-yl)pyridin-4-yl]-1H-pyrrolo[2,3-b]pyridin-5-yl]acetic acid, 2-(tert-butoxy)-2-(2-{2-[2-(dimethylamino)pyrimidin-5-yl]pyridin-4-yl}-4-(8-fluoro-5-methyl-3,4-dihydro-2H-1-benzopyran-6-yl)-1,6-dimethyl-1 H-pyrrolo[2,3-b]pyridin-5-yl)acetic acid, 2-(tert-butoxy)-2-[4-(8-fluoro-5-methyl-3,4-dihydro-2H-1-benzopyran-6-yl)-1,6-dimethyl-2-[2-(pyridin-3-yl)pyridin-4-yl]-1H-pyrrolo[2,3-b]pyridin-5-yl]acetic acid, 2-(tert-butoxy)-2-[4-(8-fluoro-5-methyl-3,4-dihydro-2H-1-benzopyran-6-yl)-1,6-dimethyl-2-[2-(1-methyl-2,3-dihydro-1H-indol-5-yl)pyridin-4-yl]-1H-pyrrolo[2,3-b]pyridin-5-yl]acetic acid, 2-(tert-butoxy)-2-[4-(8-fluoro-5-methyl-3,4-dihydro-2H-1-benzopyran-6-yl)-1,6-dimethyl-2-{2-[1-(oxan-4-yl)-1H-pyrazol-4-yl]pyridin-yl}-1H-pyrrolo[2,3-b]pyridin-5-yl]acetic acid, 2-(tert-butoxy)-2-[4-(8-fluoro-5-methyl-3,4-dihydro-2H-1-benzopyran-6-yl)-1,6-dimethyl-2-[2-(4-methylpiperazin-1-yl)pyridin-4-yl]-1 H-pyrrolo[2,3-b]pyridin-5-yl]acetic acid, 2-(tert-butoxy)-2-[4-(8-fluoro-5-methyl-3,4-dihydro-2H-1-benzopyran-6-yl)-1,6-dimethyl-2-{2-[(4-methylpiperazin-1-yl)carbonyl]pyridin-4-yl}-1H-pyrrolo[2,3-b]pyridin-5-yl]acetic acid, 2-(tert-butoxy)-2-[4-(8-fluoro-5-methyl-3,4-dihydro-2H-1-benzopyran-6-yl)-1,6-dimethyl-2-[6-(1-methyl-1H-indazol-5-yl)pyridin-3-yl]-1H-pyrrolo[2,3-b]pyridin-5-yl]acetic acid, 2-(tert-butoxy)-2-[4-(8-fluoro-5-methyl-3,4-dihydro-2H-1-benzopyran-6-yl)-1,6-dimethyl-2-{1-[(pyridin-3-yl)carbonyl]-1,2,3,6-tetrahydropyridin-4-yl}-1H-pyrrolo[2,3-b]pyridin-5-yl]acetic acid, 2-(tert-butoxy)-2-[4-(8-fluoro-5-methyl-3,4-dihydro-2H-1-benzopyran-6-yl)-1,6-dimethyl-2-{4-[(pyridin-3-yl)carbonyl]piperazin-1-yl}-1H-pyrrolo[2,3-b]pyridin-5-yl]acetic acid, 2-(tert-butoxy)-2-[4-(8-fluoro-5-methyl-3,4-dihydro-2H-1-benzopyran-6-yl)-1,6-dimethyl-2-{2-[4-(oxetan-3-yl)piperazin-1-yl]pyridin-4-yl}-1H-pyrrolo[2,3-b]pyridin-5-yl]acetic acid, 2-(tert-butoxy)-2-(4-(8-fluoro-5-methylchroman-6-yl)-1,6-dimethyl-2-(3-(4-(tetrahydro-2H-pyran-4-yl)piperazin-1-yl)-1,2,4-thiadiazol-5-yl)-1 H-pyrrolo[2,3-b]pyridin-5-yl)acetic acid, 2-(tert-butoxy)-2-(4-(8-fluoro-5-methylchroman-6-yl)-1,6-dimethyl-2-(3-(4-(tetrahydro-2H-pyran-4-yl)piperazin-1-yl)-1,2,4-oxadiazol-5-yl)-1 H-pyrrolo[2,3-b]pyridin-5-yl)acetic acid, or 2-(tert-butoxy)-2-(4-(8-fluoro-5-methylchroman-6-yl)-1,6-dimethyl-2-(5-(1-methyl-1H-indazol-5-yl)-1,3,4-oxadiazol-2-yl)-1H-pyrrolo[2,3-b]pyridin-5-yl)acetic acid, or a pharmaceutically acceptable salt thereof. 2-(tert-butoxy)-2-[4-(8-fluoro-5-methyl-3,4-dihydro-2H-1-benzopyran-6-yl)-1,6-dimethyl-2-{2-[3-(morpholin-4-yl)azetidin-1-yl]pyridin-4-yl}-1H-pyrrolo[2,3-b]pyridin-5-yl]acetic acid, 2-(tert-butoxy)-2-[4-(8-fluoro-5-methyl-3,4-dihydro-2H-1,4-benzoxazin-6-yl)-1,6-dimethyl-2-[2-(1-methyl-1H-indazol-5-yl)pyridin-4-yl]-1H-pyrrolo[2,3-b]pyridin-5-yl]acetic acid, 2-(tert-butoxy)-2-(2-{2-[2-(dimethylamino)pyrimidin-5-yl]pyridin-4-yl}-4-(8-fluoro-5-methyl-3,4-dihydro-2H-1-benzopyran-6-yl)-1,6-dimethyl-1 H-pyrrolo[2,3-b]pyridin-5-yl)acetic acid, 2-(tert-butoxy)-2-[4-(8-fluoro-5-methyl-3,4-dihydro-2H-1-benzopyran-6-yl)-1,6-dimethyl-2-[2-(pyridin-3-yl)pyridin-4-yl]-1H-pyrrolo[2,3-b]pyridin-5-yl]acetic acid, 2-(tert-butoxy)-2-[4-(8-fluoro-5-methyl-3,4-dihydro-2H-1-benzopyran-6-yl)-1,6-dimethyl-2-[2-(1-methyl-2,3-dihydro-1H-indol-5-yl)pyridin-4-yl]-1H-pyrrolo[2,3-b]pyridin-5-yl]acetic acid, 2-(tert-butoxy)-2-[4-(8-fluoro-5-methyl-3,4-dihydro-2H-1-benzopyran-6-yl)-1,6-dimethyl-2-{2-[1-(oxan-4-yl)-1H-pyrazol-4-yl]pyridin-yl}-1H-pyrrolo[2,3-b]pyridin-5-yl]acetic acid, 2-(tert-butoxy)-2-[4-(8-fluoro-5-methyl-3,4-dihydro-2H-1-benzopyran-6-yl)-1,6-dimethyl-2-[2-(4-methylpiperazin-1-yl)pyridin-4-yl]-1 H-pyrrolo[2,3-b]pyridin-5-yl]acetic acid, 2-(tert-butoxy)-2-[4-(8-fluoro-5-methyl-3,4-dihydro-2H-1-benzopyran-6-yl)-1,6-dimethyl-2-{2-[(4-methylpiperazin-1-yl)carbonyl]pyridin-4-yl}-1H-pyrrolo[2,3-b]pyridin-5-yl]acetic acid, 2-(tert-butoxy)-2-[4-(8-fluoro-5-methyl-3,4-dihydro-2H-1-benzopyran-6-yl)-1,6-dimethyl-2-[6-(1-methyl-1H-indazol-5-yl)pyridin-3-yl]-1H-pyrrolo[2,3-b]pyridin-5-yl]acetic acid, 2-(tert-butoxy)-2-[4-(8-fluoro-5-methyl-3,4-dihydro-2H-1-benzopyran-6-yl)-1,6-dimethyl-2-{1-[(pyridin-3-yl)carbonyl]-1,2,3,6-tetrahydropyridin-4-yl}-1H-pyrrolo[2,3-b]pyridin-5-yl]acetic acid, 2-(tert-butoxy)-2-[4-(8-fluoro-5-methyl-3,4-dihydro-2H-1-benzopyran-6-yl)-1,6-dimethyl-2-{4-[(pyridin-3-yl)carbonyl]piperazin-1-yl}-1H-pyrrolo[2,3-b]pyridin-5-yl]acetic acid, 2-(tert-butoxy)-2-[4-(8-fluoro-5-methyl-3,4-dihydro-2H-1-benzopyran-6-yl)-1,6-dimethyl-2-{2-[4-(oxetan-3-yl)piperazin-1-yl]pyridin-4-yl}-1H-pyrrolo[2,3-b]pyridin-5-yl]acetic acid, 2-(tert-butoxy)-2-(4-(8-fluoro-5-methylchroman-6-yl)-1,6-dimethyl-2-(3-(4-(tetrahydro-2H-pyran-4-yl)piperazin-1-yl)-1,2,4-thiadiazol-5-yl)-1 H-pyrrolo[2,3-b]pyridin-5-yl)acetic acid, 2-(tert-butoxy)-2-(4-(8-fluoro-5-methylchroman-6-yl)-1,6-dimethyl-2-(3-(4-(tetrahydro-2H-pyran-4-yl)piperazin-1-yl)-1,2,4-oxadiazol-5-yl)-1 H-pyrrolo[2,3-b]pyridin-5-yl)acetic acid, or 2-(tert-butoxy)-2-(4-(8-fluoro-5-methylchroman-6-yl)-1,6-dimethyl-2-(5-(1-methyl-1H-indazol-5-yl)-1,3,4-oxadiazol-2-yl)-1H-pyrrolo[2,3-b]pyridin-5-yl)acetic acid, or a pharmaceutically acceptable salt thereof.