The present invention relates to acid addition salts of 4-[(4-methyl-1-piperazinyl)methyl]-N-(4-methyl-3-[[4-(3-pyridinyl)-2-pyrimidinyl]amino]phenyl]-benzamide, which are selected from the group consisting of a tartrate salt, such as a (D)(-) tartrate salt or a (L)(+) tartrate salt, a hydrochloride salt, a citrate salt, a malate salt, a fumarate salt, a succinate salt, a benzoate salt, a benzenesulfonate salt, a pamoate salt, a formate salt, a malonate salt, a 1,5-naphthalenedisulfonate salt, a salicylate salt, a cyclohexanesulfamate salt, a lactate salt, a mandelate salt, aq glutarate salt, an adipate salt, a squarate salt, a vanillate salt, an oxaloacetate salt, an ascorbate salt and a sulfate salt.