A compound of formula wherein: A is aryl, wherein the aryl may be optionally substituted by one or more substituents independently selected from the group consisting of halogen, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 1 -C 6 haloalkyl, C 1 -C 6 haloalkoxy, CN, nitro, NH 2, azide, OH, C 1 -C 6 alkylamino, and R-L-; R is aryl, wherein the aryl may be optionally substituted by one, two or more substituents independently selected from the group consisting of halogen, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 1 -C 6 haloalkyl, C 1 -C 6 haloalkoxy, CN, nitro, NH 2, azide, C 1 -C 6 alkylamino optionally substituted by OH, heterocyclylamino optionally substituted by C 1 -C 6 alkyl, OH, phenyl, heterocyclyl optionally substituted by C 1 -C 6 alkyl, heterocyclyl substituted by oxo, heteroaryl, and benzyloxycarbonylamino; or heteroaryl; L is a single bond; C 1 -C 6 alkylene; C 2 -C 6 alkenylene; -(CH 2) m X -(CH 2) n -;-(CH 2) o (SO 2)NH-; -(CH 2) p N R 3 -; -(CH 2) q N R 4 -; heterocyclyl substituted by oxo; or heteroaryl; R 1 is C 1 -C 6 alkyl, optionally substituted by aryl or heteroaryl; aryl; heteroaryl; or-(CH 2) r - Y-R 5; and wherein the aryl or heteroaryl group may be optionally substituted by one or more substituents independently selected from the group consisting of halogen, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 1 -C 6 haloalkyl, C 1 -C 6 haloalkoxy, nitro, acetamido, and phenyl; R 2 is hydrogen; C 1 -C 6 alkyl, optionally substituted by aryl, heteroaryl, or by heterocyclyl and wherein the aryl or heteroaryl may be optionally substituted by one or more substituents independently selected from the group consisting of halogen, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 1 -C 6 haloalkyl, C 1 -C 6 haloalkoxy, and NH 2; or -CH 2 N R 6 R 7; m, n, o, p, q are, independently, zero or an integer from 1 to 6; r is an integer from 1 to 6; X, Y are, independently, N R 8; O; or S; R 3, R 4 are, independently, hydrogen; or C 1 -C 6 alkyl; R 5 is hydrogen, aryl or heteroaryl, wherein the aryl or heteroaryl may be optionally substituted by one or more substituents independently selected from the group consisting of halogen, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 1 -C 6 haloalkyl, C 1 -C 6 haloalkoxy, and phenyl; R 6, R 7 are, independently, hydrogen; C 1 -C 6 alkyl; or R 6 and R 7 together with the nitrogen to which they are bound form a C 4 -C 10 -heterocyclic ring, optionally containing one or more further heteroatoms in the ring independently selected from N R 9, O or S and being optionally substituted by NH 2; R 8 is hydrogen; C 1 -C 6 alkyl, optionally substituted by aryl or heterocyclyl; or C 3-6 cycloalkyl; R 9 is hydrogen or C 1 -C 6 alkyl; or stereoisomers or pharmaceutically acceptable salts thereof, for use in the treatment of diseases and conditions which are mediated by an excessive or inappropriate KDM1A activity, wherein the diseases and conditions which are mediated by an excessive or inappropriate KDM1A activity are cancer or tumors. A is aryl, wherein the aryl may be optionally substituted by one or more substituents independently selected from the group consisting of halogen, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 1 -C 6 haloalkyl, C 1 -C 6 haloalkoxy, CN, nitro, NH 2, azide, OH, C 1 -C 6 alkylamino, and R-L-; R is aryl, wherein the aryl may be optionally substituted by one, two or more substituents independently selected from the group consisting of halogen, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 1 -C 6 haloalkyl, C 1 -C 6 haloalkoxy, CN, nitro, NH 2, azide, C 1 -C 6 alkylamino optionally substituted by OH, heterocyclylamino optionally substituted by C 1 -C 6 alkyl, OH, phenyl, heterocyclyl optionally substituted by C 1 -C 6 alkyl, heterocyclyl substituted by oxo, heteroaryl, and benzyloxycarbonylamino; or heteroaryl; L is a single bond; C 1 -C 6 alkylene; C 2 -C 6 alkenylene; -(CH 2) m X -(CH 2) n -;-(CH 2) o (SO 2)NH-; -(CH 2) p N R 3 -; -(CH 2) q N R 4 -; heterocyclyl substituted by oxo; or heteroaryl; R 1 is C 1 -C 6 alkyl, optionally substituted by aryl or heteroaryl; aryl; heteroaryl; or-(CH 2) r - Y-R 5; and wherein the aryl or heteroaryl group may be optionally substituted by one or more substituents independently selected from the group consisting of halogen, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 1 -C 6 haloalkyl, C 1 -C 6 haloalkoxy, nitro, acetamido, and phenyl; R 2 is hydrogen; C 1 -C 6 alkyl, optionally substituted by aryl, heteroaryl, or by heterocyclyl and wherein the aryl or heteroaryl may be optionally substituted by one or more substituents independently selected from the group consisting of halogen, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 1 -C 6 haloalkyl, C 1 -C 6 haloalkoxy, and NH 2; or -CH 2 N R 6 R 7; m, n, o, p, q are, independently, zero or an integer from 1 to 6; r is an integer from 1 to 6; X, Y are, independently, N R 8; O; or S; R 3, R 4 are, independently, hydrogen; or C 1 -C 6 alkyl; R 5 is hydrogen, aryl or heteroaryl, wherein the aryl or heteroaryl may be optionally substituted by one or more substituents independently selected from the group consisting of halogen, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, C 1 -C 6 haloalkyl, C 1 -C 6 haloalkoxy, and phenyl; R 6, R 7 are, independently, hydrogen; C 1 -C 6 alkyl; or R 6 and R 7 together with the nitrogen to which they are bound form a C 4 -C 10 -heterocyclic ring, optionally containing one or more further heteroatoms in the ring independently selected from N R 9, O or S and being optionally substituted by NH 2; R 8 is hydrogen; C 1 -C 6 alkyl, optionally substituted by aryl or heterocyclyl; or C 3-6 cycloalkyl; R 9 is hydrogen or C 1 -C 6 alkyl;