Jie Wang

IMPORTANCE: Tumor mutational burden (TMB), as measured by whole-exome sequencing (WES) or a cancer gene panel (CGP), is associated with immunotherapy responses. However, whether TMB estimated by circulating tumor DNA in blood (bTMB) is associated with clinical outcomes of immunotherapy remains to be explored. OBJECTIVES: To explore the optimal gene panel size and algorithm to design a CGP for TMB estimation, evaluate the panel reliability, and further validate the feasibility of bTMB as a clinical actionable biomarker for immunotherapy. DESIGN, SETTING, AND PARTICIPANTS: In this cohort study, a CGP named NCC-GP150 was designed and virtually validated using The Cancer Genome Atlas database. The correlation between bTMB estimated by NCC-GP150 and tissue TMB (tTMB) measured by WES was evaluated in matched blood and tissue samples from 48 patients with advanced NSCLC. An independent cohort of 50 patients with advanced NSCLC was used to identify the utility of bTMB estimated by NCC-GP150 in distinguishing patients who would benefit from anti-programmed cell death 1 (anti-PD-1) and anti-programmed cell death ligand 1 (anti-PD-L1) therapy. The study was performed from July 19, 2016, to April 20, 2018. MAIN OUTCOMES AND MEASURES: Assessment of the Spearman correlation coefficient between bTMB estimated by NCC-GP150 and tTMB calculated by WES. Evaluation of the association of bTMB level with progression-free survival and response to anti-PD-1 and anti-PD-L1 therapy. RESULTS: This study used 2 independent cohorts of patients with NSCLC (cohort 1: 48 patients; mean [SD] age, 60 [13] years; 15 [31.2%] female; cohort 2: 50 patients; mean [SD] age, 58 [8] years; 15 [30.0%] female). A CGP, including 150 genes, demonstrated stable correlations with WES for TMB estimation (median r2 = 0.91; interquartile range, 0.89-0.92), especially when synonymous mutations were included (median r2 = 0.92; interquartile range, 0.91-0.93), whereas TMB estimated by the NCC-GP150 panel found higher correlations with TMB estimated by WES than most of the randomly sampled 150-gene panels. Blood TMB estimated by NCC-GP150 correlated well with the matched tTMB calculated by WES (Spearman correlation = 0.62). In the anti-PD-1 and anti-PD-L1 treatment cohort, a bTMB of 6 or higher was associated with superior progression-free survival (hazard ratio, 0.39; 95% CI, 0.18-0.84; log-rank P = .01) and objective response rates (bTMB ≥6: 39.3%; 95% CI, 23.9%-56.5%; bTMB <6: 9.1%; 95% CI, 1.6%-25.9%; P = .02). CONCLUSIONS AND RELEVANCE: The findings suggest that established NCC-GP150 with an optimized gene panel size and algorithm is feasible for bTMB estimation, which may serve as a potential biomarker of clinical benefit in patients with NSCLC treated with anti-PD-1 and anti-PD-L1 agents.

INTRODUCTION: Programmed death receptor-1 (PD-1) inhibitors have shown efficacy in first-line treatment of NSCLC; however, evidence of PD-1 inhibitor as neoadjuvant treatment is limited. This is a phase 1b study to evaluate the safety and outcome of PD-1 inhibitor in neoadjuvant setting. METHODS: Treatment-naive patients with resectable NSCLC (stage IA-IIIB) received two cycles of sintilimab (200 mg, intravenously, day 1 out of 22). Operation was performed between day 29 and 43. Positron emission tomography-computed tomography scans were obtained at baseline and before the operation. The primary end point was safety. Efficacy end points included rate of major pathologic response (MPR) and objective response rate. Expression of programmed cell death ligand 1 was also evaluated (registration number: ChiCTR-OIC-17013726). RESULTS: A total of 40 patients enrolled, all of whom received two doses of sintilimab and 37 underwent radical resection. A total of 21 patients (52.5%) experienced neoadjuvant treatment-related adverse events (TRAEs). Four patients (10.0%) experienced grade 3 or higher neoadjuvant TRAEs, and one patient had grade 5 TRAE. Eight patients achieved radiological partial response, resulting in an objective response rate of 20.0%. Among 37 patients, 15 (40.5%) achieved MPR, including six (16.2%) with a pathologic complete response in primary tumor and three (8.1%) in lymph nodes as well. Squamous cell NSCLC exhibited superior response compared with adenocarcinoma (MPR: 48.4% versus 0%). Decrease of maximum standardized uptake values after sintilimab treatment correlated with pathologic remission (p < 0.00001). Baseline programmed cell death ligand 1 expression of stromal cells instead of tumor cells was correlated with pathologic regression (p = 0.0471). CONCLUSIONS: Neoadjuvant sintilimab was tolerable for patients with NSCLC, and 40.5% MPR rate is encouraging. The decrease of maximum standardized uptake values after sintilimab might predict pathologic response.

IMPORTANCE: This study demonstrates that tislelizumab in combination with chemotherapy is associated with improved progression-free survival (PFS) in patients with advanced squamous non-small-cell lung cancer (sq-NSCLC). OBJECTIVE: To assess the efficacy and safety/tolerability of tislelizumab plus chemotherapy vs chemotherapy alone as first-line treatment for patients with advanced sq-NSCLC. DESIGN, SETTING, AND PARTICIPANTS: This open-label, randomized phase 3 clinical trial was conducted at 46 sites in China between July 2018 and June 2019 and included patients with treatment-naive, histologically confirmed stage IIIB/IV sq-NSCLC. The data cutoff for these analyses was December 6, 2019; data extraction occurred on January 7, 2020. INTERVENTIONS: Patients were randomized (1:1:1) to receive 1 of the following regimens intravenously on a 21-day cycle: tislelizumab (200 mg, day 1) plus paclitaxel (175 mg/m2, day 1) and carboplatin (area under the concentration of 5, day 1) (arm A); tislelizumab plus nab-paclitaxel (100 mg/m2, days 1, 8, and 15) and carboplatin (arm B); and paclitaxel and carboplatin (arm C). Patients were stratified by disease stage and tumor programmed cell death 1 ligand 1 (PD-L1) expression (<1% vs 1%-49% vs ≥50%). MAIN OUTCOMES AND MEASURES: The primary end point was progression-free survival (PFS) assessed by an independent review committee (IRC). Secondary end points included overall survival, investigator-assessed (INV) PFS, IRC-assessed objective response rate (ORR), and IRC-assessed duration of response, as well as the incidence and severity of adverse events (AEs). RESULTS: Overall, 355 patients (median [range] age, 62 [34-74] years; 330 men [91.7%]) with sq-NSCLC received treatment. After a median study follow-up of 8.6 months (95% CI, 8.1-9.0 months), IRC-assessed PFS was significantly improved with tislelizumab plus chemotherapy (arm A, 7.6 months; arm B, 7.6 months) vs chemotherapy alone (arm C, 5.5 months; hazard ratios were 0.524 (95% CI, 0.370-0.742; P < .001 [A vs C]) and 0.478 (95% CI, 0.336-0.679; P < .001 [B vs C]). Higher IRC-assessed ORR and longer IRC-assessed duration of response were observed in arms A (72.5%; 8.2 months) and B (74.8%; 8.6 months) vs C (49.6%; 4.2 months). No association was observed between PD-L1 expression and IRC-assessed PFS or ORR. Discontinuation of any treatment because of AEs was reported in 15 (12.5%; arm A), 35 (29.7%; arm B), and 18 (15.4%; arm C) patients. In each arm, the most common grade of 3 or greater AE was decreased neutrophil levels, which aligned with known chemotherapy toxic effects. Six treatment-related AEs leading to death occurred; however, no deaths were solely attributed to tislelizumab. CONCLUSIONS AND RELEVANCE: In this phase 3 randomized clinical trial, adding tislelizumab to chemotherapy was associated with significantly prolonged IRC-assessed PFS, higher IRC-assessed ORRs, and a manageable safety/tolerability profile in patients with advanced sq-NSCLC, regardless of PD-L1 expression. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03594747.