Abstract: Provided herein, in part, are compounds and compositions useful for preparing pralsetinib. Also provided herein are processes for preparing pralsetinib.

Abstract: The compound cis)-N—((S)-1-(6-(4-fluoro-1H-pyrazol-1-yl)pyridin-3-yl)ethyl)-1-methoxy-4-(4 methyl-6-(5-methyl-1H-pyrazol-3-ylamino)pyrimidin-2-yl)cyclohexanecarboxamide can be prepared as a free base in various crystalline solid forms, and in various salt forms each having one or more solid forms.

Abstract: The present disclosure relates to pharmaceutical composition comprising 1) an amorphous solid dispersion comprising pralsetinib, or a pharmaceutically acceptable salt thereof; and a pharmaceutically acceptable hydrophilic polymer; and 2) an effervescent couple; and crystalline forms of pralsetinib and pralsetinib hydrochloride salt, which are useful as a RET selective inhibitors. The present disclosure also provides pharmaceutically acceptable compositions comprising the crystalline forms and methods of using said compositions in the treatment of various disorders.