The present invention relates to novel crystal forms of 2-amino-N-[2-(3a-(R)-benzyl-2-methyl-3-oxo-2,3,3a,4,6,7-hexahydro-pyrazolo[4,3-c]pyridin-5-yl)-1-(R)-benzyloxymethyl-2-oxo-ethyl]-isobutyramide L-tartrate. More particularly, the invention relates to polymorph forms, and to processes for the preparation of, compositions containing and to uses of, such polymorph forms.