The present invention provides crystalline (R)-(E)-2-(4-(2-(5-(1-(3,5-dichloropyridin-4-yl)ethoxy)-1H-indazol-3-yl)vinyl)-1H-pyrazol-1-yl)ethanol useful in the treatment of cancer.本發明提供適用於治療癌症之結晶形(R)-(E)-2-(4-(2-(5-(1-(3,5-二氯吡啶-4-基)乙氧基)-1H-吲唑-3-基)乙烯基)-1H-吡唑-1-基)乙醇。