A fumarate salt, in particular the hemi-fumarate salt, of 5-((5-methyl-2-((3,4,5-trimethylphenyl)amino)pyrimidin-4-yl)amino)-benzo[d]oxazol-2(3H)-one (Compound (I), compositions comprising such a salt, the use of such a salt in the treatment of conditions, such as asthma and COPD, involving modulation of the JAK pathway or inhibition of JAK kinases, particularly JAK1, and processes for the manufacture of such a salt, in particular Compound (I) hemi-fumarate salt are described.描述了一種富馬酸鹽，具體是5-((5-甲基-2-((3,4,5-三甲基苯基)胺基)嘧啶-4-基)胺基)-苯并[d]㗁唑-2(3H)-酮（化合物 (I) 之半富馬酸鹽；包含此種鹽之組成物；此種鹽在治療病症如氣喘和COPD中之用途，所述治療涉及JAK途徑的調節或JAK激酶的抑制，JAK激酶具體是JAK1；以及用於製造此種鹽之方法，具體是用於製造化合物 (I) 半富馬酸鹽之方法。
