In recurrent platinum-resistant ovarian cancer, addition of pembrolizumab to chemotherapy did not result in a benefit of the therapyIn recurrent platinum-resistant ovarian cancer, this combination showed disease control rate of 65%In recurrent platinum-resistant ovarian cancer, this combination showed ORR of 62% and better OS in the group of patients with the higher CD8+PD-1+Ki67+ T cells to the tumor burden ratioCombination showed ORR of 26% in the group of patients with recurrent ovarian cancer, and results were better compared to monotherapy using each drug separately. Here, CD8A is linked to ovarian cancer.