The invention relates generally to pharmaceutical tablet compositions comprising fumaric acid and the compound (S)-2-(3'-(hydroxymethyl)-1-methyl-5-((5-(2-methyl-4- (oxetan-3-yl)piperazin-1-yl)pyridin-2-yl)amino)-6-oxo-1,6-dihydro- [3,4'-bipyridin]-2'-yl)- 7,7-dimethyl-2,3,4,6,7,8-hexahydro-1H-cyclopenta[4,5]pyrrolo[1,2-a]pyrazin-l-one free base that is an inhibitor of Bruton' s tyrosine kinase. The invention further relates to amorphous solid dispersions comprising at least one polymer and the Bruton' s kinase inhibitor free base compound. The invention further relates to crystalline mesylate salts, crystalline chloride salts and crystalline sulfate salts of the Bruton' s kinase inhibitor free base compound. In some aspects, the crystalline salts are single polymorphs.
