Provided are pharmaceutical compositions and dosage forms of 2-(tert-butylamino)-4-((1R,3R,4R)-3-hydroxy-4-methylcyclohexylamino)-pyrimidine-5-carboxamide, or a pharmaceutically acceptable stereoisomer, tautomer, solid form, polymorph, salt, hydrate, clathrate, or solvate thereof. Also provided are methods of treating, managing, or preventing various disorders, such as diseases or disorders treatable or preventable by inhibition of a JNK pathway in mammals using such pharmaceutical compositions or dosage forms. Further provided are salts of 2-(tert-butylamino)-4-((1R,3R,4R)-3-hydroxy-4-methylcyclohexylamino)-pyrimidine-5-carboxamide and methods of preparation of such salts.