CD274 and non-small cell lung carcinoma: Accordingly epacadostat, an IDO1 inhibitor, has shown early efficacy and safety in phase I and II trials and is currently being studied in a phase III trial in combination with pembrolizumab in advanced NSCLC patients with a PD-L1 TPS score ≥ 50%, though it’s combination with pembrolizumab in patients with unresectable or metastatic melanoma did not improve PFS or OS over placebo + pembrolizumab [104,105].