Sintilimab, an anti-programmed death 1 antibody, plus pemetrexed and platinum had revealed promising efficacy for nonsquamous NSCLC in a phase 1b study. We conducted a randomized, double-blind, phase 3 study to compare the efficacy and safety of sintilimab with placebo, both in combination with such chemotherapy (ClinicalTrials.gov: NCT03607539). A total of 397 patients with previously untreated, locally advanced or metastatic nonsquamous NSCLC without sensitizing EGFR or anaplastic lymphoma kinase genomic aberration were randomized (2:1 ratio) to receive either sintilimab 200 mg or placebo plus pemetrexed and platinum once every 3 weeks for four cycles, followed by sintilimab or placebo plus pemetrexed therapy. Crossover or treatment beyond disease progression was allowed. The primary end point was progression-free survival (PFS) as judged by an independent radiographic review committee. As of November 15, 2019, the median follow-up was 8.9 months. The median PFS was significantly longer in the sintilimab-combination group than that in the placebo-combination group (8.9 versus 5.0 mo; hazard ratio, 0.482, 95% confidence interval [CI]: 0.362-0.643; p < 0.00001). The confirmed objective response rate was 51.9% (95% CI: 45.7%-58.0%) in the sintilimab-combination group and 29.8% (95% CI: 22.1%-38.4%) in placebo-combination group. The incidence of grade 3 or higher adverse events was 61.7% in sintilimab-combination group and 58.8% in placebo-combination group. In Chinese patients with previously untreated, locally advanced or metastatic nonsquamous NSCLC, the addition of sintilimab to chemotherapy with pemetrexed and platinum resulted in considerably longer PFS than with chemotherapy alone with manageable safety profiles.

PD-L1 expression is a feature of Epstein-Barr virus (EBV) associated malignancies such as nasopharyngeal carcinoma (NPC). Here, we found that EBV-induced latent membrane protein 1 (LMP1) and IFN-γ pathways cooperate to regulate programmed cell death protein 1 ligand (PD-L1). Expression of PD-L1 was higher in EBV positive NPC cell lines compared with EBV negative cell lines. PD-L1 expression could be increased by exogenous and endogenous induction of LMP1 induced PD-L1. In agreement, expression of PD-L1 was suppressed by knocking down LMP1 in EBV positive cell lines. We further demonstrated that LMP1 up-regulated PD-L1 through STAT3, AP-1, and NF-κB pathways. Besides, IFN-γ was independent of but synergetic with LMP1 in up-regulating PD-L1 in NPC. Furthermore, we showed that PD-L1 was associated with worse disease-free survival in NPC patients. These results imply that blocking both the LMP1 oncogenic pathway and PD-1/PD-L1 checkpoints may be a promising therapeutic approach for EBV positive NPC patients.