The invention provides new salts and polymorphs of (5R,8S)-7-[(2S)-2-{[(2S)-2-cyclohexyl-2-({[(2S)-1-isopropylpiperidin-2-yl]carbonyl}amino)acetyl]amino}-3,3-dimethyl butanoyl]-N-{(1R,2R)-2-ethyl-1-[(pyrrolidin-1-ylsulfonyl)carbamoyl]cyclopropyl}-10,10-dimethyl-7-azadispiro[3.0.4.1]decane-8-carboxamide (referred to herein as Compound X), pharmaceutical compositions containing them and processes for their manufacture and use in therapy.