Association Of Tumor Mutational Burden Research Articles

Assessment of Tumor Mutational Burden and Outcomes in Patients With Diverse Advanced Cancers Treated With Immunotherapy

There are few studies assessing the association of tumor mutational burden (TMB) and clinical outcomes in a large cohort of patients with diverse advanced cancers. To clinically validate a TMB biomarker from a next-generation sequencing targeted gene panel assay. A prespecified cohort study using the deidentified clinicogenomic Tempus database of patients sequenced between 2018 and 2022, which contained retrospective, observational data originating from 300 cancer sites including 199 community sites and 101 academic sites. Patients with advanced solid tumors across 8 cancer types and more than 20 histologies, sequenced with Tempus xT who were treated with immune checkpoint inhibitors (ICIs) in the first-line or second-line setting were included. Data were analyzed from September 2018 to August 2022. Treatment with US Food and Drug Administration (FDA)-approved antiprogrammed cell death-1/programmed cell death-ligand 1 (PD-1/PD-L1) ICI and/or in combination with a cytotoxic T-lymphocyte-associated protein-4 ICI. The primary outcome was the association of tumor mutational burden (TMB) binary category (high [≥10 mut/mb] vs low) with overall survival (OS) in patients treated with ICIs. Secondary outcomes were progression-free survival (PFS), and time to progression (TTP). In the evaluable cohort of 674 patients, the median (IQR) age was 69.4 (28.6-89.8) years, 271 patients (40.2%) were female, and 435 patients (64.5%) were White. The most common advanced cancers were non-small cell lung cancer (330 patients [49.0%]), followed by bladder cancer (148 patients [22.0%]), and head and neck squamous cell carcinoma (96 patients [14.8%]). Median (IQR) follow-up was 7.2 (3.2-14.1) months. High TMB (TMB-H) cancers (206 patients [30.6%]) were significantly associated with longer OS than low TMB (TMB-L) cancers (hazard ratio [HR], 0.72; upper confidence bound [UCB], 0.91; P = .01). In a prospective subset of 403 patients treated with ICIs after TMB testing, TMB-H cancers (135 patients [33.5%]) were significantly associated with longer OS (HR, 0.61; UCB, 0.84; P = .005), PFS (HR, 0.62; UCB, 0.82; P = .003), and TTP (HR, 0.67; UCB, 0.92; P = .02) than TMB-L cancers. An overall survival benefit was seen regardless of the type of ICI used (pembrolizumab, 339 patients; HR, 0.67; UCB, 0.94; P = .03), other ICIs (64 patients; HR, 0.37; UCB, 0.85; P = .03), and after adjusting for PD-L1 and microsatellite stability status (403 patients; HR = 0.67; UCB, 0.92; P = .02). In this cohort study of patients with advanced solid tumors treated with ICIs in diverse clinics, TMB-H cancers were significantly associated with improved clinical outcomes compared with TMB-L cancers.

Abstract CT077: Association of tumor mutational burden (TMB) and clinical outcomes with tislelizumab versus chemotherapy in esophageal cell carcinoma (ESCC) from RATIONALE-302

Abstract Background: Programmed cell death protein 1 (PD-1) inhibitors are approved as second-line (2L) therapy for patients (pts) with ESCC. TMB is a predictive biomarker of response to immune checkpoint blockade in multiple cancers, but its role in ESCC is unclear. Here, we retrospectively investigated the association between TMB and clinical outcomes in the phase 3 RATIONALE-302 study of anti-PD-1 antibody tislelizumab (TIS) vs investigator-chosen chemotherapy (ICC) as 2L treatment for advanced unresectable/metastatic ESCC (NCT03430843). Methods: Genomic profiling was assessed on tumor tissues collected at baseline using BurningRock OncoScreen Plus 520 NGS panel to determine TMB status. Median progression-free survival (PFS) and overall survival (OS) were calculated using the Kaplan-Meier method. Objective response rate (ORR) was calculated using the binomial exact method. Cox model was applied to assess the effect of TMB on survival outcomes. Hazard ratio (HR) and 95% confidence interval (CI) for OS and PFS in TMB subgroups were estimated. Results: Of 512 pts enrolled, 209 had evaluable tumor samples (TIS, n=105; ICC, n=104). Using the widely used cutoff of 10 mutations per megabase (mut/Mb), numerically higher ORR and survival benefit with TIS over ICC were observed in the high TMB (TMB-H) vs the low TMB (TMB-L) subgroup (Table). The predictive effect of TMB on survival outcomes was not significant (interaction p-value = 0.0537 for PFS, 0.5374 for OS); however, the effect became significant using the increased cutoff of 12 mut/Mb (TMB-H prevalence = 16.7%; interaction p-value = 0.0267 for PFS, 0.0175 for OS). Conclusions: TMB status may play a role in predicting clinical outcomes in pts with advanced ESCC treated with TIS versus ICC, especially when a higher TMB cutoff is chosen. These findings need further prospective validation. Acknowledgments: This study was sponsored by BeiGene, Ltd. Medical writing support, under the direction of the authors, was provided by Sophie Cook, PhD, of Ashfield MedComms, an Inizio company, and was funded by BeiGene, Ltd. Table. Clinical outcomes by TMB status (cutoff 10 mut/Mb) TMB status TMB-H TMB-L Treatment TIS ICC TIS ICC n (% in TMB BEP, N=209) 27 (12.9) 31 (14.8) 78 (37.3) 73 (34.9) ORR, % (95% CI) 33.3 (16.5, 54.0) 6.5 (0.8, 21.4) 16.7 (9.2, 26.8) 17.8 (9.8, 28.5) Median PFS, months (95% CI) 2.4 (1.4, 5.5) 2.3 (1.3, 2.9) 1.4 (1.3, 2.7) 2.7 (1.5, 3.3) PFS HR (95% CI) 0.52 (0.28, 0.97) 1.06 (0.73, 1.53) Interaction p-value 0.0537 Median OS, months (95% CI) 6.1 (4.2, 18.6) 4.7 (3.4, 7.0) 8.6 (4.6, 11.8) 7.0 (4.6, 8.6) OS HR (95% CI) 0.58 (0.32, 1.04) 0.72 (0.50, 1.03) Interaction p-value 0.5374 TMB-adjusted OS HR (95% CI) 0.68 (0.5, 0.92) BEP, biomarker evaluable population; CI, confidence interval; HR, hazard ratio; ICC, investigator chosen chemotherapy; OS, overall survival; PFS, progression-free survival; ORR, objective response rate; TIS, tislelizumab; TMB-H, high tumor mutational burden; TMB-L, low tumor mutational burden; TMB-adjusted OS HR, overall HR adjusted for the impact of TMB on OS Citation Format: Lin Shen, Yongqian Shu, Kuaile Zhao, Taroh Satoh, Zhendong Chen, Eric Van Cutsem, Guohua Yu, Jun Wu, Chih-Hung Hsu, Sung Bae Kim, Wenting Du, Yang Shi, Ruiqi Huang, Qiao Li, Jingwen Shi, Yun Zhang, Kato Ken. Association of tumor mutational burden (TMB) and clinical outcomes with tislelizumab versus chemotherapy in esophageal cell carcinoma (ESCC) from RATIONALE-302 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr CT077.

From tumor mutational burden to characteristic targets analysis: Identifying the predictive biomarkers and natural product interventions in cancer management.

High-throughput next-generation sequencing (NGS) provides insights into genome-wide mutations and can be used to identify biomarkers for the prediction of immune and targeted responses. A deeper understanding of the molecular biological significance of genetic variation and effective interventions is required and ultimately needs to be associated with clinical benefits. We conducted a retrospective observational study of patients in two cancer cohorts who underwent NGS in a “real-world” setting. The association between differences in tumor mutational burden (TMB) and clinical presentation was evaluated. We aimed to identify several key mutation targets and describe their biological characteristics and potential clinical value. A pan-cancer dataset was downloaded as a verification set for further analysis and summary. Natural product screening for the targeted intervention of key markers was also achieved. The majority of tumor patients were younger adult males with advanced cancer. The gene identified with the highest mutation rate was TP53, followed by PIK3CA, EGFR, and LRP1B. The association of TMB (0–103.7 muts/Mb) with various clinical subgroups was determined. More frequent mutations, such as in LRP1B, as well as higher levels of ferritin and neuron-specific enolase, led to higher TMB levels. Further analysis of the key targets, LRP1B and APC, was performed, and mutations in LRP1B led to better immune benefits compared to APC. APC, one of the most frequently mutated genes in gastrointestinal tumors, was further investigated, and the potential interventions by cochinchinone B and rottlerin were clarified. In summary, based on the analysis of the characteristics of gene mutations in the “real world,” we obtained the potential association indicators of TMB, found the key signatures LRP1B and APC, and further described their biological significance and potential interventions.

The association of tumor mutational burden, microsatellite stability, and mismatch repair deficiency in an endometrial cancer patient cohort (194)

The association of tumor mutational burden, microsatellite stability, and mismatch repair deficiency in an endometrial cancer patient cohort (194)

Abstract LB512: RATIONALE-304: The association of tumor mutational burden (TMB) with clinical outcomes of tislelizumab (TIS) + chemotherapy (chemo) versus chemo alone as first-line treatment for advanced non-squamous non-small cell lung cancer (nsq-NSCLC)

Abstract Background: In the primary analysis of RATIONALE-304 (NCT03663205), TIS + platinum-based chemo significantly improved clinical outcomes over chemo alone in treatment-naïve advanced nsq-NSCLC (median progression-free survival [PFS] by IRC [9.7 vs 7.6 months, HR=0.645, p=0.0044]). Here we report biomarker analysis of baseline tissue and blood TMB (tTMB and bTMB, respectively). Methods: Patients with nsq-NSCLC were randomized 2:1 to TIS + platinum + pemetrexed or platinum + pemetrexed. TMB scores were evaluated on baseline tumor and blood samples by OncoScreen Plus®. The Spearman’s rank correlation of tTMB with bTMB was assessed. PFS by independent review committee (primary endpoint) was assessed within subgroups defined by TMB status, using a Cox proportional hazard model with disease stage and programmed death-ligand 1 (PD-L1) expression as stratification factors. Interaction p-values < 0.05 were considered statistically significant without multiplicity adjustment. Results: Of 325 patients treated in RATIONALE-304, without an EGFR sensitizing mutation, 177 (54.5%) had evaluable tTMB and 107 (32.9%) had evaluable bTMB. Median tTMB and bTMB were 7.2 and 3.1 mut/Mb, respectively. There was a modest correlation between tTMB and bTMB (r=0.71, p < 0.001). Prolonged PFS benefit of adding TIS to chemo was oberved in patients with TMB-high status compared with TMB-low status (Table). Interaction analysis showed that neither tTMB nor bTMB significantly differentiated treatment-specific PFS benefit (interaction p-values > 0.05; Table). Conclusions: In this retrospective analysis, neither tTMB nor bTMB was significantly associated with PFS benefit, suggesting limited clinical utility of tTMB and bTMB in the setting of TIS + chemo as first-line therapy for advanced nsq-NSCLC. Association of TMB with PFS benefit of TIS + chemo vs chemo tTMB bTMB Cutoffs mut/Mb N HR (95% CI) Interaction Cutoffs mut/Mb N HR (95% CI) Interaction p-value p-value BEP 177 0.76 (0.46, 1.25) NA BEP 107 0.48 (0.26, 0.87) NA ≥ 8 (TMB-high) 80 0.52 (0.25, 1.10) 0.208 ≥ 4 (TMB-high) 47 0.30 (0.12, 0.75) 0.212 < 8 (TMB-low) 97 0.98 (0.51, 1.88) < 4 (TMB-low) 60 0.64 (0.29, 1.39) BEP, biomarker evaluable population; bTMB, blood tumor mutational burden; CI, confidence interval; HR, hazard ratio; Mb, megabase; mut, mutation; NA, not applicable; PFS, progression-free survival; TIS, tislelizumab; TMB, tumor mutational burden; tTMB, tissue tumor mutational burden Citation Format: Shun Lu, Meili Sun, Yunpeng Liu, Yanping Hu, Yanyan Xie, Zhehai Wang, Dong Wang, Zhenzhou Yang, Liang Liang, Yi Huo, Yun Zhang, Ruiqi Huang, Yang Shi, Zhirong Shen, Yan Yu. RATIONALE-304: The association of tumor mutational burden (TMB) with clinical outcomes of tislelizumab (TIS) + chemotherapy (chemo) versus chemo alone as first-line treatment for advanced non-squamous non-small cell lung cancer (nsq-NSCLC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr LB512.

RF3 The association of tumor mutational burden, microsatellite stability, and mismatch repair deficiency in an endometrial cancer patient cohort

RF3 The association of tumor mutational burden, microsatellite stability, and mismatch repair deficiency in an endometrial cancer patient cohort

Role of TMB and PD-L1 as Prognostic Factors and Predictors of Response to Immunotherapy in Head and Neck Squamous Cell Cancer

<h3>Purpose/Objective(s)</h3> Immunotherapy with checkpoint inhibitors (ICI) improved survival in HNSCC. Response rates to ICIs remain low, in part due to lack of effective predictors of response to guide patients' selection. PD-L1, as the only biomarker used in prospective research of ICI in HNSCC has generated inconsistent results. Developments in Precision Oncology in HNSCC brings the prospect for new biomarkers. Tumor mutational burden (TMB) is under investigation in many solid tumors and this study assessed the significance and potential role of TMB and PD-L1 in the immunotherapy of HNSCC. <h3>Materials/Methods</h3> This single institution retrospective review includes HNSCC patients (pts) with tumor tissue evaluated for PD-L1 (IHC 22C3 pharmDx kit) and TMB by FoundationOne. PD-L1 was reported as TPS score (prior to 2018) or CPS score (thereafter). TMB and PD-L1 were analyzed for individual association with demographics, disease characteristics and survival, and with progression free survival (PFS) and response to ICI. Pts tested for TMB (mut/Mb) were grouped as TMB(1-5) and TMB(6+) and pts tested for PD-L1 were grouped as PD-L1(0), PD-L1(1-19) and PD-L1(20+). <h3>Results</h3> 139 pts were included, 128 pts had TMB, 95 pts had PD-L1 and 92 pts had both results. TMB(6+) was associated with smoking (p=0.03) and with tumor location, with laryngeal cancer pts having higher TMB (p<0.01) and oropharyngeal cancer pts having lower TMB (p p<0.01). PD-L1 was higher in African Americans (p=0.04), in never smokers (p=0.04) and never drinkers (p=0.01), and in pts with earlier cancer stage (p=0.03) and lower tumor stage (p p<0.01). There was no correlation of TMB or PD-L1 with HPV status. TMB(6+) was associated with improved survival in univariate analysis (p=0.02) and in Cox proportional hazards regression model adjusted for age, tobacco, tumor site, nodal stage, previous chemo/radiotherapy and PD-L1 level (p<0.01). No correlation was found between PD-L1 level and prognosis. There was no correlation between TMB and PD-L1 level. Treatment efficacy with ICI was evaluated in 51 pts, of whom 40 pts had TMB and 36 pts had PD-L1 results. There was significant association of continuous TMB score with PFS (p=0.013) and with response to ICI (mean TMB=11.2 in responders and 4.9 in non-responders; p=0.01). Similarly, in categorical analysis, PFS was 538 days in TMB(6+) and 261 days in TMB(1-5) (p=0.04). There was no association between response to ICI or PFS and PD-L1 analyzed as categorical (p=0.89 and p=0.62) or continuous variable (p=0.99 and p=0.66). <h3>Conclusion</h3> Inadequate PD-L1 results in this study could be explained by inconsistence in methods. The association of TMB with prognosis and response to ICI in this study warrants further investigations, and prompts a methodology harmonization effort and advancement of TMB in future prospective studies. The recent availability of circulating TMB makes it a further attractive biomarker.

Tumor mutational burden predicts the efficacy of pembrolizumab monotherapy: a pan-tumor retrospective analysis of participants with advanced solid tumors

BackgroundSeveral studies have evaluated the relationship between tumor mutational burden (TMB) and outcomes of immune checkpoint inhibitors. In the phase II KEYNOTE-158 study of pembrolizumab monotherapy for previously treated recurrent...

Association of tumor mutational burden with genomic alterations in Chinese urothelial carcinoma.

The tumor mutational burden (TMB) calculated by whole-exome sequencing (WES) is a promising biomarker for the response to immune checkpoint inhibition (ICIs) in solid tumors. However, WES is not feasible in the routine clinical setting. In addition, the characteristics of the TMB in Chinese urothelial carcinoma (UC) are unclear. The aim of this study was to demonstrate the reliability of an Acornmed 808 panel and analyze the characteristics of the TMB in Chinese UC.An Acornmed 808 panel was designed and virtually validated using UC data from the cancer genome atlas (TCGA). Comprehensive analysis of sequencing and clinical data was performed to explore the characteristics of the TMB for 143 Chinese UC patients.Compared to the TMB calculated with random 808-, 500-, and 250-gene panels, the TMB calculated with the Acornmed 808 panel was closer to that calculated by WES. There were marked disparities in the mutational landscape and TMB between Chinese and TCGA UC data. The TMB was negatively associated with copy number variation (CNV). In contrast, the TMB was positive correlation with numbers of mutated DDR genes. Exposure to aristolochic acid signature was observed only in the TMB-high groups.The Acornmed 808 panel is a clinically practical method to assess the TMB. The TMB was associated with the DDR gene status and CNV counts and might be a biomarker for further stratification of UC patients. The study suggested that patients with high TMB may have a unique carcinogenic mechanism.

372 Association of tumor mutation burden (TMB) and genomic alterations (GA) with clinical outcomes in Chinese patients with advanced solid tumors treated with tislelizumab

BackgroundStudies have demonstrated correlation of GA and TMB with clinical efficacy of an anti-programmed cell death protein-1 (PD-1) therapy, but this correlation has not yet been demonstrated in Chinese patients treated with tislelizumab (anti-PD-1 antibody). We report the association between TMB, GA, and the clinical efficacy of tislelizumab in Chinese patients with different tumor types from a Phase 1/2 study (NCT04068519).MethodsChinese patients with advanced solid tumors who received tislelizumab monotherapy and had available tissues for genomic testing (BurningRock OncoScreen Plus 520 NGS panel) were eligible. Patients were classified as having hyper-amplification (HA) if their genome harbored ≥1 amplified gene with a copy number &gt;5. Logistic regression was used to analyze the association of TMB with objective response rate (ORR) and Cox proportional hazard was used to determine the association of TMB with progression-free survival (PFS) and overall survival (OS).ResultsA total of 156 patients were evaluable. TMB was higher in responders (R) versus non-responders (NR) (median [m] TMB: 9.3 vs 6.2 mut/Mb, p=0.003). TMB-H was defined as ≥8 mut/Mb according to the receiver operating characteristic curve. Patients in the TMB-H group showed superior clinical benefit compared with the TMB-L group (table 1). Further GA analysis showed a trend toward a higher frequency of HA in NR (40.00%; 16/40) compared with R (28.78%; 5/18), in the TMB-H group. A total of 33.33% (10/30) of these amplified genes in NR belonged to the RTK-RAS-PI3K signaling pathway. When TMB-H patients with HA in this pathway were excluded, ORR reached 37.78%.Abstract 372 Table 1Median study follow-up and clinical efficacy dataNE, non-estimableConclusionsTMB-H status was associated with improved clinical efficacy of tislelizumab in Chinese patients with advanced solid tumors, consistent with other PD-1 inhibitors. These observations support TMB-H as a potential predictive biomarker for response to tislelizumab in this patient population. HA in the RTK-RAS-PI3K pathway may be associated with resistance mechanisms to anti-PD-1 therapy, even in patients with TMB-H tumors.AcknowledgementsEditorial writing support for the development of this abstract, under direction of the authors, was provided by Louise Oakes, PhD, of Ashfield MedComms, an Ashfield Health company, and was funded by BeiGene Ltd.Trial RegistrationNCT04068519Ethics ApprovalThis study was conducted according to the ethical principles of the Declaration of Helsinki, Good Clinical Practice guidelines, the principles of informed consent and the requirements of the public registration of clinical trials. Written informed consent was obtained from each patient prior to screening. The protocol was approved by the institutional ethics committee and was monitored by the investigators and study sponsor.

PD-L1 Expression Is Significantly Associated with Tumor Mutation Burden and Microsatellite Instability Score

Simple SummaryBiomarkers for predicting the response to immune checkpoint blockade (ICB) includes programmed death-ligand 1 (PD-L1) immunohistochemistry (IHC), microsatellite instability (MSI), and tumor mutation burden (TMB). This study investigated the relationship of these biomarkers using comprehensive cancer panel assay (CCPA) with >500 genes in 588 advanced cancer patients. The work demonstrates that PD-L1 expression is significantly associated with TMB and MSI score, according to primary tumor origin.Programmed death-ligand 1 (PD-L1) immunohistochemistry (IHC), microsatellite instability (MSI), and tumor mutation burden (TMB) have been proposed as a predictive biomarker to predict response to immune checkpoint blockade (ICB). We aimed to find the relationship of PD-L1 IHC to TMB and MSI using a comprehensive cancer panel assay (CCPA) with >500 genes in advanced cancer patients. CCPA results from 588 archived tissue samples were analyzed for TMB and MSI. In seven samples, whole exome sequencing confirmed TMB with Pearson’s correlation coefficient of 0.972 and all MSI-high cases were validated by pentaplex PCR. Association of TMB and MSI with their corresponding PD-L1 IHC was analyzed. The median TMB value of 588 cases was 8.25 mutations (mut)/Mb (range 0–426.8) with different distributions among the tumor types, with high proportions of high-TMB (>10mut/Mb) in tumors from melanoma, colorectal, gastric, and biliary tract. The TMB values significantly correlated with PD-L1 expression, and this correlation was prominent in gastric and biliary tract cancers. Moreover, the MSI score, the proportion of unstable MSI sites to total assessed MSI sites, showed a significant correlation with the TMB values and PD-L1 scores. This study demonstrates that PD-L1 expression is significantly associated with TMB and MSI score and this correlation depends on the location of the primary tumor.

Clinical and utilization outcomes associated with tumor mutational burden in a real-world pan-tumor population.

Aim & methods: This real-world study examined the association of tumor mutational burden (TMB) with clinical and healthcare utilization in adults diagnosed with advanced solid tumor 1 January2015- 31 January2019. Results: There were 170 patients in low-TMB group (TMB<10mut/Mb) and 32 in high-TMB group (TMB ≥10mut/Mb). Median overall survival was 18.8 (95% CI: 17.3-28.8) and 15.9months (95% CI: 11.3-18.0) whereas median progression-free survival was 9.9 (95% CI: 8.6-11.4) and 7.8months (95% CI: 3.8-12.5) for the low- and high-TMB groups, respectively. Hospitalization (49.4 vs 37.5%), emergency visit (25.3 vs 21.9%), and median overall cost of care (US$135,403 vs 87,570) were all lower in low-TMB group. Conclusion: Despite the limited sample, these data provide a historical perspective for examining real-world outcomes associated with TMB.

Immune related biomarkers in biliary tract cancers (BTC).

e16191 Background: Biliary tract cancers are aggressive tumors with limited treatment options. Several ongoing clinical trials are currently exploring role of immune therapy in advanced BTC. Programmed death-ligand 1 (PD-L1), tumor mutational burden (TMB), and microsatellite instability (MSI) are commonly used immune related-biomarkers. Herein, we analyzed the TMB, MSI and PD-L1 expression in advanced BTC. Methods: We retrospectively evaluated the association of TMB, MSI and PD-L1 expression with survival and related treatment outcomes. Results: The immune mediated biomarkers were reported in a total of 62 BTC patients (pts). The mean age of the pts is 73 (range 32-83) years, with predominant females (59%) and Caucasians (82%). The most common histology noted was intrahepatic cholangiocarcinoma (67%) followed by extrahepatic cholangiocarcinoma (18%) and gallbladder carcinoma (15%). Approximately, 40% received 2 or more lines of therapy while 20% of patients didn’t receive any treatment and over. The treatment regimen included gemcitabine-based regimen (35%), 5FU based regimen (18%), immune therapy (15%) and targeted therapy (6%). The TMB was low in 52 pts (83%), intermediate 7 pts (11%) and high in 2 pts (3%). MSI is stable in 55 pts (89%) and PD-L1 expression is negative in 29 pts (47%) and positive in 23 pts (37%). Conclusions: Our data suggests the BTC’s have in general low TMB, are microsatellite stable and have low PD-L1 expression. The potential prognostic and predictive value of these immune related- biomarkers need to be validated in larger studies.

The association between tumor mutational burden and prognosis is dependent on treatment context.

In multiple cancer types, high tumor mutational burden (TMB) is associated with longer survival after treatment with immune checkpoint inhibitors (ICI). The association of TMB with survival outside of the immunotherapy context is poorly understood. We analyzed 10,233 patients (80% non-ICI-treated, 20% ICI-treated) with 17 cancer types, before/without ICI treatment, or after ICI treatment. In non-ICI-treated patients, higher TMB (higher percentile within cancer type) was not associated with better prognosis; in fact, in many cancer types, higher TMB was associated with poorer survival, in contrast to ICI-treated patients, in whom higher TMB was associated with longer survival.

Association of tumor mutation burden and epidermal growth factor receptor inhibitor history with survival in patients with metastatic stage III/IV non-small-cell lung cancer: A retrospective study

OBJECTIVES:Lung cancer is the leading cause of cancer-related deaths worldwide. However, factors associated with the survival of patients with advanced non-small-cell lung cancer (NSCLC) who received only hospice care are largely unclear. In this study, we aimed to determine the prognostic factors correlated with survival in patients with advanced NSCLC who had undergone hospice care only.METHODS:A total of 102 patients with recurrent stage III/IV NSCLC after traditional treatment failure were investigated. Survival was measured from the date of enrollment to December 2019 or the time of death. Tumor tissues were collected, and DNA sequencing was performed to identify somatic mutations. Data on clinical factors of patients were collected and analyzed by univariate and multivariate analyses. Overall survival analysis was conducted using the Kaplan-Meier method.RESULTS:The 6-month, 1-year, and 2-year overall survival rates of the 102 patients with metastatic NSCLC were 17.65%, 3.92%, and 0.98%, respectively. The median overall survival of the 102 patients was 3.15 months. Tumor location in the peripheral lung, epidermal growth factor receptor (EGFR) inhibitor history, low tumor mutation load, adenocarcinoma, and poor performance status score were associated with prolonged survival compared with tumor location in the central lung, no EGFR inhibitor history, high tumor mutation load, squamous cell carcinoma, and good performance status score (p=0.045, p=0.003, p=0.045, p=0.021, and p=0.0003, respectively). CONCLUSIONS:EGFR inhibitor treatment history and tumor mutation load are risk factors for the overall survival of patients with stage III/IV NSCLC who have undergone only hospice care. These results provide a critical clinical basis for further study of nontraditional anti-tumor responses induced by EGFR inhibitors.

Significance of Tumor Mutation Burden in Immune Infiltration and Prognosis in Cutaneous Melanoma.

Background: Melanoma is highly immunogenic and therefore suitable for immunotherapy, but the efficacy is limited by response rate. In several types of tumor, tumor mutation burden (TMB) and immune infiltration have been reported to predict the response to immunotherapy, although each has its limitations. In the current study, we aimed to explore the association of TMB with immune infiltration and prognosis in cutaneous melanoma.Methods: The data of cutaneous melanoma used for analyses was downloaded from The Cancer Genome Atlas (TCGA) database. The mutation data was sorted using “maftools” R package. TMB was estimated and then patients were divided into two groups based on TMB. The association of TMB with prognosis and clinical characteristics was explored. Differential analysis between two TMB groups was performed using “DESeq2” R package to identify differentially expressed genes (DEGs). The function enrichment analyses of DEGs were conducted to screen critical pathways. Besides, DEGs were further filtered to identify two hub genes, based on which a risk score model and nomogram for predicting prognosis were conducted, and the validation was performed using three datasets from Gene Expression Omnibus (GEO) database. Finally, CIBERSORT algorithm and TIMER database were used to assess the effect of TMB and hub genes on immune infiltration.Results: The most common mutation was C > T, and the top three frequently mutated genes were TTN, MUC16, and BRAF. Higher TMB indicated better survival outcomes and lower pathological stages. 735 DEGs were identified and mainly involved in immune-related and adhesion-related pathways. The risk score model and nomogram were validated using receiver operating characteristic (ROC) curves and calibration curves, and exhibited relatively high predictive capability. Decision curve analysis (DCA) was used to assess clinical benefit. As for immune infiltration, the proportion was higher for macrophages M1 and M2 in the high-TMB group, while lower for memory B cells and regulatory T cells.Conclusions: In cutaneous melanoma, TMB was positively correlated with prognosis. The risk score model and nomogram can be conveniently used to predict prognosis. The association of TMB with immune infiltration can help improve the predicting methods for the response to immunotherapy.

Association of tumor mutational burden (TMB) and clinical outcomes with pembrolizumab (pembro) versus chemotherapy (chemo) in patients with metastatic triple-negative breast cancer (mTNBC) from KEYNOTE-119.

1013 Background: In the randomized, open-label, phase 3 KEYNOTE-119 study (NCT02555657) , OS was not significantly different with pembro monotherapy versus chemo in second- or third-line settings for mTNBC; however, the pembro treatment effect increased with increasing PD-L1 enrichment. We evaluated the association of TMB with efficacy of pembro monotherapy versus chemo in patients with previously treated mTNBC. Methods: Patients with centrally confirmed TNBC and 1 or 2 prior systemic treatments for metastatic disease were enrolled. Patients were randomly assigned 1:1 to pembro 200 mg Q3W or single-agent chemo per investigator’s choice of capecitabine, eribulin, gemcitabine, or vinorelbine. Association of TMB, as measured by FoundationOne CDx (Foundation Medicine), with response was an exploratory objective evaluated using receiver operator characteristic (ROC) analysis, logistic regression (ORR), and Cox regression (OS; PFS) within treatment arms; estimates of efficacy based on TMB cutpoint used a prespecified cutpoint of 10 mut/Mb. Results: TMB data were available for 253/601 (42.1%) treated patients (pembro, n = 132; chemo, n = 121); baseline characteristics were similar to that of the overall study population. One-sided P values for the association of TMB and clinical outcomes in pembro-treated patients were 0.154 for ORR, 0.014 for PFS, and 0.018 for OS; the area under the ROC curve ([AUROC] 95% CI) for predicting ORR was 0.58 (0.43-0.73). Two-sided P values for the association of TMB and clinical outcomes in chemo-treated patients were 0.114 for ORR, 0.478 for PFS, and 0.906 for OS; AUROC (95% CI) was 0.43 (0.27-0.59). Twenty-six patients had TMB ≥10 mut/Mb. Thus, the prevalence of TMB ≥10 mut/Mb was ~10%. Outcomes based on TMB cutpoint are reported in the Table. Conclusions: Data from this exploratory analysis from KEYNOTE-119 suggest a potential positive association between TMB and clinical benefit with pembro but not chemo in patients with mTNBC. Although precision is limited by sample size and the number of patients with TMB ≥10 mut/Mb, ORR and HRs for OS suggested a trend towards increased benefit with pembro versus chemo in patients with TMB ≥10 mut/Mb. Clinical trial information: NCT02555657 . [Table: see text]

Molecular biomarkers to identify patients (pts) who may benefit from durvalumab (D; anti-PD-L1) ± tremelimumab (T; anti-CTLA-4) in recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC) from HAWK and CONDOR studies.

6548 Background: Baseline tumor and germline biomarkers in R/M HNSCC were analyzed for predictive potential in pts benefitting from D or D+T. Methods: In HAWK (NCT02207530), 112 pts (PD-L1 tumor cells [TC]≥25%) received D (10 mg/kg Q2W for ≤12 m); in CONDOR (NCT02319044), 67 pts (PD-L1 TC &lt; 25%) received D (10 mg/kg Q2W for ≤12 m), 133 pts received D+T (D 20 mg/kg Q4W, T 1 mg/kg Q4W for ≤12 m), and 67 pts received T (10 mg/kg Q4W [7 doses] then Q12W [2 doses] for ≤12 m) VENTANA PD-L1 (SP263) Assay determined PD-L1 status. Paired FFPE archival tumor and PBMC samples (as germline control) in the HAWK and CONDOR trials were evaluated by whole exome sequencing (WES). Tumor mutation burden (TMB) was number of somatic mutations/megabase. HLA class I types were obtained via WES of PBMCs (CONDOR only). HPV and neutrophil-to-lymphocyte ratio (NLR) were tested locally in CONDOR. Wilcoxon, log-rank tests, and COX-PH models were used. Pooled D &amp; D+T data were analyzed unless noted. Results: 153 pts had paired evaluable FFPE tumor and PBMC samples (HAWK, n = 48; CONDOR, n = 105). TMB distributions were similar between studies ( P= 0.43). TMB correlated with smoking ( P= 0.02) but not HPV ( P= 0.24), NLR ( P= 0.66), or PD-L1 status ( P= 0.43). Overall, high TMB (≥upper tertile) trended with longer OS vs low TMB in all evaluable pts (N = 153; 9.0 vs 5.6 m; HR = 0.70; 95% CI = 0.48-1.01); P= 0.06). In HAWK, there was no association of TMB with OS. In CONDOR, pts (D and D+T arms) with high TMB vs low had significantly longer OS (N = 76; 16.3 vs 5.3 m; HR = 0.53; 95% CI = 0.31-0.92). TMB and OS association was further assessed by increasing TMB cutoffs. Improved HRs trended with higher cutoffs; cutoffs ≥upper quartile significantly linked to OS.TMB was not associated with PFS or ORR. Pts with low PD-L1 and low TMB had worse OS compared to pts with high PD-L1 or high TMB. Pts with high NLR (≥median) and low TMB had significantly worse OS than pts with low NLR and high TMB (HR = 2.63, P&lt; 0.001). Analysis of germline HLA alleles revealed significantly poorer survival for carriers of the HLA-B*15:01 allele (9.4%) (HLA-B variant status did not affect TMB and OS association in CONDOR). Germline HLA heterozygosity did not impact OS. Pts with mutations in ATM (5%), a DNA damage repair gene, also trended with prolonged OS. Conclusions: TMB is a possible predictive biomarker of IO HNSCC therapy. Combined analysis of NLR and TMB may provide additional PD-L1 data in assessing pts most likely to have long-term benefit. Clinical trial information: NCT002207530, NCT02319044 .

Association of tumor mutational burden with age in solid tumors.

e13590 Background: Immunotherapy is becoming one of the promising treatments for cancer administration, and several studies indicated a better outcome was received in patients with high tumor mutation burden (TMB). The distribution of TMB is still unknown and this study aimed to analysis the association between TMB and age especially in East Asian populations. Methods: In our study, TMB value was measured as the numbers of synonymous, nonsynonymous mutations and InDels by next generation sequencing with 539 genes panel in tumor tissue. TMB-H was defined as highest mutation load quintile (top 20%) in each cancer type. The association between TMB and age in 874 patients was investigated including 174 patients with liver cancer, 32 patients with bile duct cancer, 54 patients with gastric cancer, 119 patients with colorectal cancer, 27 patients with pancreatic cancer, 32 patients with melanoma, 25 patients with glioma and 411 patients with lung cancer cases, respectively. Spearman rank correlation analysis, Mann-Whitney U-test and Fisher’s exact test were used for statistical analysis. Results: A significant correlation between TMB and ages was observed in patients with solid tumors (r = 0.204, p = 1.263×10−9). The median age of included patients was 60 years-old. Based on nonparametric test, the value of TMB in patients with liver cancer ( p = 2.310×10−4), gastric cancer ( p = 0.029) and lung cancer ( p = 0.001) aged ≥ 60 years-old was significantly higher than the corresponding patients aged &lt; 60 years-old. No significant differences of TMB values were found between patients &lt; 60 and ≥ 60 years-old in bile duct cancer ( p = 0.419), colorectal cancer ( p = 0.075), pancreatic cancer ( p = 1), melanoma ( p = 0.952) and glioma ( p = 0.720). The TMB-H ratio in patients with liver ( p = 0.049) and gastric ( p = 0.015) cancer aged &lt; 60 years old was significantly lower than patients aged ≥ 60 years-old. Conclusions: Our study indicated the TMB value and TMB-H ratio were relatively higher with ages ≥ 60 years old in specific tumors, which might provide useful information to guide precisely the the application of PD-1 or PD-L1 inhibitors. As a retrospective study with a relatively small population, the conclusions of this study needed to be verified with a larger sample.

Validation of 3-factor clinical-genomic model to predict response to atezolizumab as first-line or post-platinum therapy for advanced urothelial carcinoma.

552 Background: Previously, we reported a 3-factor model including tumor mutation burden (TMB), peripheral blood neutrophil/lymphocyte ratio (NLR) and visceral metastasis status to predict tumor regression (c-statistic=0.90) when using ICIs for mUC regardless of line of therapy. We conducted an external validation of this model to determine its ability to predict response. Methods: We utilized data from a phase II trial, IMvigor210, which evaluated atezolizumab (atezo) for post-platinum pts or as first-line therapy for cisplatin-ineligible pts with mUC. Pts with TMB, NLR, visceral metastasis and RECIST1.1 response status available were evaluable. Tumor genomic analysis was performed using FoundationOne, which sequences 324 cancer-related genes. Multivariable regression studied the association of TMB (&lt;10 vs. ≥10 mutations/megabase), NLR (&lt;5 vs. ≥5) and visceral metastasis status (yes vs.no) with RECIST 1.1 response status (≥partial response [PR] vs no PR). Model discrimination performance was assessed using the concordance (c)-index. Results: A total of 234 pts were evaluable for analysis, of whom 185 (79%) were men. 164 (70.1%) pts received post-platinum therapy and 70 (29.9%) received first-line therapy with atezo. 60 pts exhibited RECIST 1.1 ≥PR. On multivariate analysis, all 3 factors were independently and significantly associated with ≥PR: TMB ≥10 mutations/megabase (HR -4.254, p=2.1 x 10−5), low NLR (HR=2.591, p=0.00958) and absence of visceral metastasis status (HR=4.105, p=4.04 x 10−5). The c-index of this 3-factor model to predict ≥PR was 0.77. Presence of all 3 favorable factors (TMBhigh, NLRlow, no visceral metastases) was associated with ≥PR in 15/21 pts (71.4%), while the absence of all 3 factors (TMBlow, NLRhigh, visceral metastases) was associated with ≥PR in 2/37 pts (5.4%). Conclusions: A 3-factor model combining readily available clinical and genomic variables including TMB, NLR and visceral metastasis status was validated to robustly predict RECIST 1.1 response in pts with mUC receiving atezo as first-line or post-platinum therapy. This model may improve the therapeutic index and cost efficacy of atezo.