Background: Blockade of the CTLA-4 pathway with ipilimumab (IPI) as monotherapy or in combination with nivolumab (anti–PD-1) is an effective treatment for a variety of cancers. Nonfucosylation of an anti–CTLA-4 antibody increased binding affinity to CD16, induced depletion of Tregs while increasing T-effector cells in mouse tumors, and enhanced tumor growth inhibition in a dose-dependent manner, thus demonstrating improved ADCC compared with IPI. An ongoing phase 1/2 study is evaluating the safety and antitumor activity of anti–CTLA-4 NF alone and in combination with nivolumab (NCT03110107) in patients with advanced solid cancers.