The present invention provides an amino pyrazole compound, which is 3-[(lR)-6-fluoro-2,3-dihydro-1H-inden-l-yl]-N-(3- methyl-IH- pyrazol-5-yl)-3H-imidazo[4,5-b]pyridin-5-amine, or a pharmaceutically acceptable salt thereof, that inhibits JAK1 and JAK2 and, therefore may be useful in treating cancer.