The present disclosure provides for compounds according to Formula I or Formula II and their pharmaceutically acceptable salts, stereoisomers, and/or tautomers thereof, as described in the present disclosure. Also provided are pharmaceutical compositions and methods of using the compounds for treating cancers, including some cancers in which the gene encoding methylthioadenosine phosphorylase (MTAP) is deleted.本發明提供根據式I或式II之化合物及其醫藥學上可接受之鹽、立體異構體及/或其互變異構體,如本發明中所描述。亦提供醫藥組合物及使用該等化合物治療癌症之方法,該等癌症包括缺失編碼甲硫基腺苷磷酸化酶(MTAP)之基因的一些癌症。