The present invention relates to bicyclic heterocycles, and pharmaceutical compositions of the same, that are inhibitors of the FGFR4 enzyme and are useful in the treatment of FGFR4-associated diseases such as cancer.本發明係關於雙環雜環及其醫藥組合物,其為FGFR4酶之抑制劑且適用於治療FGFR4相關疾病,諸如癌症。