The invention relates to: 2-Amino-N-[(R)-l-benzyloxymethyl-2-((4S,5R)-2-methyl-l- oxo-4- phenyl-2,7-diaza-spiro[4.5]dec-7-yl)-2-oxo-ethyl]-2-methyl- propionamide L- malate salt, 2-amino-N-((2R)-3-(benzyloxy)-l-(2-methyl-l-oxo-4-p-tolyl- 2,7- diazaspiro[4.5]decan-7-yi)-l-oxopropan-2-yi)-2-methyipropanamide L- malate salt and 2-Amino-N-((R)-l-benzyloxymethyl-2-[(45,5R)-4-fluoro- phenyl) -2-methyl-l-oxo-2,7-diaza-spiro[4,5]dec-7-yl]-2-oxoethyl}2- methylpropionamide L-malate salt and to the crystalline forms thereof; pharmaceutical compositions comprising such compounds and such compounds for the treatment of a disorder or a disease mediated by the ghrelin receptor.