CD33 and leukemia: A treatment study was designed to evaluate the therapeutic efficacy of [225Ac]Macropa-PEG4-7065 (Figure 6A), with groups including vehicle control, non-targeting [225Ac]Macropa-PEG4-IgG, the previously evaluated leukemia RIT [225Ac]DOTA-anti-CD33, and [225Ac]Macropa-PEG4-7065.