CTLA4 and ovarian carcinoma: However, the combination of 2 immune checkpoint blockade agents (the anti-PD-1 nivolumab and the anti-CTLA-4 ipilimumab) in 100 patients with persistent or recurrent ovarian cancer was superior to the guadecitabine/pembrolizumab combination, with 12% response rate in the nivolumab group and 31% response rate in the combination group.