The invention relates to a combination which comprises:(a) Compound A ((R)-3-(4-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-1H-pyrazol-1-yl)-3-cyclopentylpropanenitrile) of Formula (A):or a pharmaceutically acceptable salt thereof; and(b) Compound B (N-hydroxy-3-[4-[[[2-(2-methy-1H-indol-3-yl)-ethyl]-amino]methyl]phenyl]-2E-2-propenamide) of Formula (B):or a pharmaceutically acceptable salt thereof;for simultaneous, concurrent, separate or sequential use, especially for use in the treatment of proliferative diseases. The invention also relates to pharmaceutical compositions comprising such a combination and to a method of treating proliferative diseases, in a mammal, particularly a human, with such a combination. The present invention further also relates to a commercial package or product comprising such a combination.