A checkpoint kinase 1 inhibitor (CHK1) selected from the group consisting of (R) -N- (4- (3- aminopiperidin-1-yl) -5-bromo-1H-pyrrolo [2,3-b] pyridin-3-yl) nicotinamide； (R) -N- (4- (3-aminopiperidin-1-yl) -5-bromo-1Hpyrrolo [2,3-b] pyridin-3-yl) isobutyramide； (R) -N- (5-bromo-4- (3- (methylamino) piperidin-1-yl) -1H-pyrrolo [2,3-b] pyridin-3- yl) nicotinamide； (R) -N- (4- (3-aminopiperidin-1-yl) -5-bromo-1H-pyrrolo [2,3-b] pyridin-3-yl) -5-methylnicotinamide； (R) -N- (4- (3- aminopiperidin-1-yl) -5-bromo-1H-pyrrolo [2,3-b] pyridin-3-yl) cyclopropanecarboxamide, (R) -N- (4- (3-aminopiperidin-1-yl) -5-bromo-1H-pyrrolo [2,3-b] pyridin-3-yl) -3-methylbutanamide； and (R) -N- (4- (3-aminopiperidin-1-yl) -5-bromo-1H-pyrrolo [2,3- b] pyridin-3-yl) -2-cyclopropylacetamide for administration to a patient suffering from cancer for use in potentiating a DNA damaging agent in a method of treating cancer, wherein the administration of the CHK1 inhibitor follows the administration of the DNA damaging agent, wherein the CHK1 inhibitor is administered in two doses, the first dose of CHK1 inhibitor is administered one day after the DNA damaging agent and the second dose of CHK1 inhibitor is administered two days after the DNA damaging agent.Un inhibidor de quinasa de punto de control 1 (CHK1) seleccionado del grupo constituido por (R)-N-(4-(3- aminopiperidin-1-il)-5-bromo-1H-pirrolo[2,3-b]piridin-3-il)nicotinamida； (R)-N-(4-(3-aminopiperidin-1-il)-5-bromo-1Hpirrolo[ 2,3-b]piridin-3-il)isobutiramida； (R)-N-(5-bromo-4-(3-(metilamino)piperidin-1-il)-1H-pirrolo[2,3-b]piridin-3- il)nicotinamida； (R)-N-(4-(3-aminopiperidin-1-il)-5-bromo-1H-pirrolo[2,3-b]piridin-3-il)-5-metilnicotinamida； (R)-N-(4-(3- aminopiperidin-1-il)-5-bromo-1H-pirrolo[2,3-b]piridin-3-il)ciclopropanocarboxamida, (R)-N-(4-(3-aminopiperidin-1-il)-5- bromo-1H-pirrolo[2,3-b]piridin-3-il)-3-metilbutanamida； y (R)-N-(4-(3-aminopiperidin-1-il)-5-bromo-1H-pirrolo[2,3- b]piridin-3-il)-2-ciclopropilacetamida para la administra
