Currently, there are 11 ADCs approved by FDA (Table 1) covering indications such as CD33-positive acute myeloid leukaemia, HER2-positive metastatic breast cancer, locally advanced or metastatic urothelial cancer, large B-cell lymphoma (Drago et al., 2021; Khongorzul et al., 2020). Here, CD33 is linked to acute myeloid leukemia.