An exploration of LAF-bTMB as a predictor for the efficacy of immunotherapy combined with chemotherapy in non-small cell lung cancer.

Immune checkpoint inhibitor (ICI) combined with chemotherapy is one of the standards of care for advanced non-small cell lung cancer (NSCLC) without driver mutations. However, the biomarker of combination therapy is still unknown. Although previous studies have confirmed that low allele frequency adjusted blood-based tumor mutational burden (LAF-bTMB) is associated with the efficacy of ICI monotherapy, there has been no report on the correlation between the efficacy of LAF-bTMB and ICI combined chemotherapy. This study aimed to explore whether LAF-bTMB can be used as a predictive biomarker for the efficacy of immunotherapy combined with chemotherapy in advanced NSCLC. This study enrolled patients diagnosed with advanced NSCLC and who received ICI combined with chemotherapy for first-line therapy from May 2020 to December 2021 at Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College. Clinical information, treatment information, survival data, and peripheral blood samples of every patient before treatment were collected. Next-generation sequencing was performed on plasma samples to estimate bTMB and LAF-bTMB. A total of 42 patients with NSCLC were enrolled. In this cohort, 19 patients achieved partial response (PR), and the objective response rate (ORR) was 45.2%. The median progression-free survival (PFS) of all patients was 13.4 months (95% CI, 7.49-19.72). Both PFS and the overall survival (OS) were significantly longer in the responder (R) group than in the non-responder (NR) group (median PFS, 16.4 months vs. 7.2 months, p = 0.028; median OS, NE vs. 9.3 months, p = 0.016). There was no significant difference in bTMB and LAF-BTMB between the R and NR group. The ORR of patients with LAF-bTMB≤8muts/Mb was significantly higher than that of patients with LAF-bTMB >8muts/Mb (ORR, 61% vs. 26%, respectively, p = 0.033). When LAF-bTMB ≤8muts/Mb or > 20muts/Mb, ORR was significantly higher than that of patients with LAF-bTMB between 8 and 20muts/Mb (ORR were 57% and 21%, p = 0.047). No correlation has been found between LAF-bTMB and PFS or OS. This study confirmed that neither bTMB nor LAF-bTMB is feasible as a potential predictor of first-line immunochemotherapy for advanced NSCLC. More suitable biomarkers need to be explored to screen patients with better efficacy of immunotherapy combined with chemotherapy in the future.

Zhang S ，Yang L ，Yang Y ，Xin Y ，Wang Y ... -  《-》

Allele Frequency-Adjusted Blood-Based Tumor Mutational Burden as a Predictor of Overall Survival for Patients With NSCLC Treated With PD-(L)1 Inhibitors.

Blood-based tumor mutational burden (bTMB) has been studied to identify patients with NSCLC who would benefit from anti-programmed cell death protein 1 (anti-PD-1) or anti-programmed death ligand 1 (anti-PD-L1) therapies. However, it failed to predict overall survival (OS) benefits, which warrants further exploration. Three independent cohorts of patients with NSCLC treated with immunotherapy were used in this study. A new bTMB algorithm was first developed in the two independent cohorts (POPLAR, N = 211, and OAK, N = 462) and further validated in the third National Cancer Center (NCC) cohort (N = 64). bTMB-H (bTMB ≥ cutoff point) was not associated with favorable OS after immunotherapy regardless of the cutoff points in either the POPLAR and OAK or the NCC cohorts (p > 0.05) owing to its correlation with the amount of circulating tumor DNA, which was associated with poor OS. In the POPLAR and OAK cohorts, with allele frequency (AF) adjustment, a high AF bTMB (HAF-bTMB, mutation counts with an AF > 5%) was strongly correlated with the amount of circulating tumor DNA (Pearson r = 0.65), whereas a low AF bTMB (LAF-bTMB, mutation counts with an AF ≤ 5%) was not (Pearson r = 0.09). LAF-bTMB-H was associated with favorable OS (hazard ratio [HR] = 0.70, 95% confidence interval [CI]: 0.52-0.95, p = 0.02), progression-free survival (PFS; HR = 0.62, 95% CI: 0.47-0.80, p < 0.001), and objective response rate (ORR) (p < 0.001) after immunotherapy but not chemotherapy, with a cutoff point of 12 trained in the POPLAR cohort and validated in the OAK cohort. The LAF-bTMB algorithm was further validated in the NCC cohort in which LAF-bTMB-H was associated with OS (HR = 0.20, 95% CI: 0.05-0.84, p = 0.02), PFS (HR = 0.30, 95% CI: 0.13-0.70, p = 0.003), and ORR (p = 0.001). We developed and validated a new LAF-bTMB algorithm as a feasible predictor of OS, PFS, and ORR after anti-PD-(L)1 therapies in patients with NSCLC, which needs to be prospectively validated.

Wang Z ，Duan J ，Wang G ，Zhao J ，Xu J ，Han J ，Zhao Z ，Zhao J ，Zhu B ，Zhuo M ，Sun J ，Bai H ，Wan R ，Wang X ，Fei K ，Wang S ，Zhao X ，Zhang Y ，Huang M ，Huang D ，Qi C ，Gao C ，Bai Y ，Dong H ，Xiong L ，Tian Y ，Wang D ，Xu C ，Wang W ，Li J ，Hu X ，Cai S ，Wang J ... -  《-》

Dynamic bTMB combined with residual ctDNA improves survival prediction in locally advanced NSCLC patients with chemoradiotherapy and consolidation immunotherapy.

Wang Y ，Wang W ，Zhang T ，Yang Y ，Wang J ，Li C ，Xu X ，Wu Y ，Jiang Y ，Duan J ，Wang L ，Bi N ... -  《JNCC-Journal of the National Cancer Center》

Blood tumor mutation burden can predict the clinical response to immune checkpoint inhibitors in advanced non-small cell lung cancer patients.

Tissue tumor mutation burden (tTMB) assessed by whole-exome sequencing (WES), which has been regarded as the gold standard method of tTMB measurement, can predict the clinical benefits of immune checkpoint inhibitors (ICIs). Multiple studies have investigated the feasibility of utilizing large panels to evaluate TMB but have obtained conflicting results. Furthermore, whether blood TMB (bTMB) can also be a predictive biomarker in NSCLC has not been determined. Fifty-six advanced NSCLC patients treated with ICIs were enrolled, including an exploratory cohort (n = 42) and a small independent validation cohort (n = 14). Next-generation sequencing was performed on tumor and plasma samples collected prior to ICI treatment using a panel consisting of 520 cancer-related genes (OncoScreen) to evaluate tTMB/bTMB. WES was also performed on tumor samples to serve as references. A positive correlation between tTMB derived from WES and OncoScreen was observed. OncoScreen-derived tTMB showed a positive correlation with OncoScreen-derived bTMB. Patients with OncoScreen-derived tTMB [Formula: see text] 7 mutations/Mb (p = 0.003) or bTMB [Formula: see text] 11 mutations/Mb (p = 0.0029) had superior progression-free survival (PFS). In the small validation cohort, patients with OncoScreen-derived bTMB [Formula: see text] 11 mutations/Mb exhibited longer PFS (p = 0.192) with a nonsignificant difference. In all 42 patients who had available bTMB and PFS, patients with bTMB [Formula: see text] 11 mutations/Mb had significantly longer PFS (p = 0.011) than those with bTMB [Formula: see text] 11 mutations/Mb. Our study confirmed the feasibility of using large panels to estimate TMB. We also demonstrated that bTMB can serve as a potential biomarker for predicting the efficacy of ICIs in NSCLC.

Chen X ，Fang L ，Zhu Y ，Bao Z ，Wang Q ，Liu R ，Sun W ，Du H ，Lin J ，Yu B ，Chen S ，Zhou J ，Zhou J ... -  《-》

The relationship between blood-based tumor mutation burden level and efficacy of PD-1/PD-L1 inhibitors in advanced non-small cell lung cancer: a systematic review and meta-analysis.

The predictive role of blood-based tumor mutation burden (bTMB) for selecting advanced nonsmall cell lung cancer (NSCLC) patients who might benefit from immune checkpoint inhibitors (ICIs) is still under debate. Therefore, the purpose of this meta-analysis was to evaluate the efficacy of programmed cell death 1 (PD-1) /programmed cell death ligand 1 (PD-L1) inhibitors versus that of standard-of-care therapy in patients with NSCLC who were bTMB high and bTMB low. PubMed, Embase, Cochrane, the Web of Science, and ClinicalTrials.gov were searched systematically from inception to February 2021 for studies of PD-1/PD-L1 inhibitors (durvalumab OR atezolizumab OR avelumab OR pembrolizumab OR Nivolumab) that provided hazard ratios (HRs) for overall survival (OS) or progression-free survival (PFS), or odds ratios (ORs) for objective response rate (ORR) in both bTMB high and bTMB low groups. A total of 2338 patients with advanced or metastatic NSCLC from six randomized controlled trials, which all used chemotherapy (CT) as a control, were included in this study. Compared with CT, PD-1/PD-L1 inhibitor therapy improved OS (HR 0.62, 95% CI 0.52-0.75, P < 0.01), PFS (HR 0.57, 95% CI 0.48-0.67, P < 0.01), and ORR (OR 2.69, 95% CI 1.84-3.93, P < 0.01) in bTMB-high NSCLC patients but not in bTMB-low patients (OS HR 0.86, 95% CI 0.69-1.07, P = 0.17; PFS HR 1.00, 95% CI 0.78-1.27, P = 0.98; ORR OR 0.63, 95% CI 0.49-0.80, P = 0.03). Subgroup analyses showed that these results were consistent across all subgroups (line of therapy, therapy regimen, type of NGS panel, PD-L1 expression, and cutoff value). Meta-regression analysis showed that the proportion of patients with squamous cell histology had no statistical effect on clinical outcomes. Sensitivity analyses illustrated that all results were stable. The efficacy of PD-1/PD-L1 inhibitor therapy in advanced NSCLC patients may be dependent on bTMB level. Patients with high bTMB tend to obtain significantly better OS, PFS, and ORR from PD-1/PD-L1 inhibitor therapy than from CT. However, because of multiple limitations, including those related to reproducibility, the results are exploratory and should be interpreted with caution.

Ba H ，Liu L ，Peng Q ，Chen J ，Zhu YD ... -  《BMC CANCER》