CD274 and ovarian carcinoma: AVB-S6-500 is undergoing Phase I and II clinical trials in combination with avelumab (anti-PD-L1) in patients with urothelial carcinoma (phase II, NCT04004442), or with durvalumab (anti-PD-L1) in platinum-resistant and recurrent ovarian cancers (phase I/II, NCT04019288).