Association of potential biomarkers with clinical outcomes in metastatic triple-negative breast cancer treated with pembrolizumab or chemotherapy

Currently, predictive biomarkers for response to immune checkpoint inhibitor (ICI) therapy in lung cancer are limited. Identifying such biomarkers would be useful to refine patient selection and guide precision therapy. To develop a machine-learning (ML)-based tumor-infiltrating lymphocytes (TILs) scoring approach, and to evaluate TIL association with clinical outcomes in patients with advanced non-small cell lung cancer (NSCLC). This multicenter retrospective discovery-validation cohort study included 685 ICI-treated patients with NSCLC with median follow-up of 38.1 and 43.3 months for the discovery (n = 446) and validation (n = 239) cohorts, respectively. Patients were treated between February 2014 and September 2021. We developed an ML automated method to count tumor, stroma, and TIL cells in whole-slide hematoxylin-eosin-stained images of NSCLC tumors. Tumor mutational burden (TMB) and programmed death ligand-1 (PD-L1) expression were assessed separately, and clinical response to ICI therapy was determined by medical record review. Data analysis was performed from June 2021 to April 2022. All patients received anti-PD-(L)1 monotherapy. Objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) were determined by blinded medical record review. The area under curve (AUC) of TIL levels, TMB, and PD-L1 in predicting ICI response were calculated using ORR. Overall, there were 248 (56%) women in the discovery cohort and 97 (41%) in the validation cohort. In a multivariable analysis, high TIL level (≥250 cells/mm2) was independently associated with ICI response in both the discovery (PFS: HR, 0.71; P = .006; OS: HR, 0.74; P = .03) and validation (PFS: HR = 0.80; P = .01; OS: HR = 0.75; P = .001) cohorts. Survival benefit was seen in both first- and subsequent-line ICI treatments in patients with NSCLC. In the discovery cohort, the combined models of TILs/PD-L1 or TMB/PD-L1 had additional specificity in differentiating ICI responders compared with PD-L1 alone. In the PD-L1 negative (<1%) subgroup, TIL levels had superior classification accuracy for ICI response (AUC = 0.77) compared with TMB (AUC = 0.65). In these cohorts, TIL levels were robustly and independently associated with response to ICI treatment. Patient TIL assessment is relatively easily incorporated into the workflow of pathology laboratories at minimal additional cost, and may enhance precision therapy.

&lt;div&gt;AbstractPurpose:&lt;p&gt;This prespecified exploratory analysis evaluated the association between tumor mutational burden (TMB) status and outcomes of first-line pembrolizumab±chemotherapy versus chemotherapy in KEYNOTE-062.&lt;/p&gt;Patients and Methods:&lt;p&gt;In patients with advanced gastric cancer and evaluable TMB data, we evaluated the association between TMB (continuous variable; square root scale) assessed with FoundationOne CDx and clinical outcomes [objective response rate (ORR), progression-free survival (PFS), and overall survival (OS)] using logistic (ORR) and Cox proportional hazards (PFS, OS) regression models. Clinical utility of TMB was assessed using the prespecified cutoff of 10 mut/Mb.&lt;/p&gt;Results:&lt;p&gt;TMB data were available for 306 of 763 patients (40.1%; pembrolizumab, 107; pembrolizumab+chemotherapy, 100; chemotherapy, 99). TMB was significantly associated with clinical outcomes in patients treated with pembrolizumab and pembrolizumab+chemotherapy (ORR, PFS, and OS; all &lt;i&gt;P&lt;/i&gt; &lt; 0.05) but not with chemotherapy (all &lt;i&gt;P&lt;/i&gt; &gt; 0.05). The overall prevalence of TMB ≥10 mut/Mb was 16% across treatment groups; 44% of patients who had TMB ≥10 mut/Mb had high microsatellite instability (MSI-H) tumors. Improved clinical outcomes (ORR, PFS, and OS) were observed in pembrolizumab-treated patients (pembrolizumab monotherapy and pembrolizumab+chemotherapy) with TMB ≥10 mut/Mb. When the analysis was limited to the non–MSI-H subgroup, both the positive association between clinical outcomes with pembrolizumab or pembrolizumab+chemotherapy and TMB as a continuous variable and the clinical utility of pembrolizumab (with or without chemotherapy) versus chemotherapy by TMB cutoff were attenuated.&lt;/p&gt;Conclusions:&lt;p&gt;This exploratory analysis of KEYNOTE-062 suggests an association between TMB and clinical efficacy with first-line pembrolizumab-based therapy in patients with advanced gastric/gastroesophageal junction adenocarcinoma. However, after the exclusion of patients with MSI-H tumors, the clinical utility of TMB was attenuated.&lt;/p&gt;&lt;/div&gt;

&lt;div&gt;AbstractPurpose:&lt;p&gt;This prespecified exploratory analysis evaluated the association between tumor mutational burden (TMB) status and outcomes of first-line pembrolizumab±chemotherapy versus chemotherapy in KEYNOTE-062.&lt;/p&gt;Patients and Methods:&lt;p&gt;In patients with advanced gastric cancer and evaluable TMB data, we evaluated the association between TMB (continuous variable; square root scale) assessed with FoundationOne CDx and clinical outcomes [objective response rate (ORR), progression-free survival (PFS), and overall survival (OS)] using logistic (ORR) and Cox proportional hazards (PFS, OS) regression models. Clinical utility of TMB was assessed using the prespecified cutoff of 10 mut/Mb.&lt;/p&gt;Results:&lt;p&gt;TMB data were available for 306 of 763 patients (40.1%; pembrolizumab, 107; pembrolizumab+chemotherapy, 100; chemotherapy, 99). TMB was significantly associated with clinical outcomes in patients treated with pembrolizumab and pembrolizumab+chemotherapy (ORR, PFS, and OS; all &lt;i&gt;P&lt;/i&gt; &lt; 0.05) but not with chemotherapy (all &lt;i&gt;P&lt;/i&gt; &gt; 0.05). The overall prevalence of TMB ≥10 mut/Mb was 16% across treatment groups; 44% of patients who had TMB ≥10 mut/Mb had high microsatellite instability (MSI-H) tumors. Improved clinical outcomes (ORR, PFS, and OS) were observed in pembrolizumab-treated patients (pembrolizumab monotherapy and pembrolizumab+chemotherapy) with TMB ≥10 mut/Mb. When the analysis was limited to the non–MSI-H subgroup, both the positive association between clinical outcomes with pembrolizumab or pembrolizumab+chemotherapy and TMB as a continuous variable and the clinical utility of pembrolizumab (with or without chemotherapy) versus chemotherapy by TMB cutoff were attenuated.&lt;/p&gt;Conclusions:&lt;p&gt;This exploratory analysis of KEYNOTE-062 suggests an association between TMB and clinical efficacy with first-line pembrolizumab-based therapy in patients with advanced gastric/gastroesophageal junction adenocarcinoma. However, after the exclusion of patients with MSI-H tumors, the clinical utility of TMB was attenuated.&lt;/p&gt;&lt;/div&gt;

This prespecified exploratory analysis evaluated the association between tumor mutational burden (TMB) status and outcomes of first-line pembrolizumab±chemotherapy versus chemotherapy in KEYNOTE-062. In patients with advanced gastric cancer and evaluable TMB data, we evaluated the association between TMB (continuous variable; square root scale) assessed with FoundationOne CDx and clinical outcomes [objective response rate (ORR), progression-free survival (PFS), and overall survival (OS)] using logistic (ORR) and Cox proportional hazards (PFS, OS) regression models. Clinical utility of TMB was assessed using the prespecified cutoff of 10 mut/Mb. TMB data were available for 306 of 763 patients (40.1%; pembrolizumab, 107; pembrolizumab+chemotherapy, 100; chemotherapy, 99). TMB was significantly associated with clinical outcomes in patients treated with pembrolizumab and pembrolizumab+chemotherapy (ORR, PFS, and OS; all P < 0.05) but not with chemotherapy (all P > 0.05). The overall prevalence of TMB ≥10 mut/Mb was 16% across treatment groups; 44% of patients who had TMB ≥10 mut/Mb had high microsatellite instability (MSI-H) tumors. Improved clinical outcomes (ORR, PFS, and OS) were observed in pembrolizumab-treated patients (pembrolizumab monotherapy and pembrolizumab+chemotherapy) with TMB ≥10 mut/Mb. When the analysis was limited to the non-MSI-H subgroup, both the positive association between clinical outcomes with pembrolizumab or pembrolizumab+chemotherapy and TMB as a continuous variable and the clinical utility of pembrolizumab (with or without chemotherapy) versus chemotherapy by TMB cutoff were attenuated. This exploratory analysis of KEYNOTE-062 suggests an association between TMB and clinical efficacy with first-line pembrolizumab-based therapy in patients with advanced gastric/gastroesophageal junction adenocarcinoma. However, after the exclusion of patients with MSI-H tumors, the clinical utility of TMB was attenuated.

9066 Background: Current biomarker(s) for immuno-oncology (IO) therapy response prediction in lung cancer are limited. Additional predictive biomarkers are useful to help refine patient selection and guide precision therapy. Methods: Biopsy and surgical specimens stained with hematoxylin-eosin (H&amp;E) were subjected to whole-slide scanning for 446 advanced stage non-small cell lung cancer (NSCLC) treated with single agent immune check point inhibitors (ICI). A machine learning model was trained on H&amp;E images for classification of tumor infiltrating lymphocytes (TILs), tumor cells, and stromal cells in specific tissue types. Results: TIL levels were found to be highly variable, with a range of 12 to 4270 cells/mm2, and median of 319 (Q1 = 159, Q3 = 681). TIL levels were assessed on tissue samples from multiple organs which had shown primary or metastatic NSCLC, and were similar across all specimen sites except the liver, for which median TIL levels were significantly lower, at 90 cells/mm2. There was no correlation between tumor mutational burden (TMB) and TIL levels, while high TIL levels were correlated with high PD-L1 (≥ 50%) expression. Patients who experienced a partial/complete response to ICI therapy had a trend to higher median TILs compared to those who had progressive/stable disease (350 versus 310 cells/mm2, P = 0.09). In a multivariable analysis after controlling for covariates (incl. sex, age, cigarette smoking, ECOG, PD-L1, TMB &amp; treatment line), a higher TIL level (≥ 250 cells/mm2) was an independent predictor of IO response for both progression-free survival (PFS; HRadj 0.70; 95% CI, 0.55 - 0.89; P = 0.003) and overall survival (HRadj 0.73; 95% CI, 0.56 - 0.95; P = 0.02). In a ROC analysis considering single biomarkers, PD-L1 had the highest AUC (0.68, P &lt; 0.001), while TIL (AUC = 0.53, P = 0.08) and TMB (AUC = 0.55, P = 0.05) had similar AUC values for classifying responders from non-responders based on objective response rate. Using weighted linear regression approach to combine the biomarkers, paired PD-L1/TMB had the greatest AUC (0.70, P &lt; 0.001) compared to PD-L1 single assay. In the PD-L1 negative (&lt; 1%, N = 50) subgroup, TIL levels had superior predictive performance for classification of IO responders (AUC = 0.77, P = 0.02) compared to TMB (AUC = 0.57, P = 0.3), such that patients with a high TIL level (≥ 250 cells/mm2) had an improved PFS (median PFS: 2.7 vs 2.2 months; HR = 0.48; 95% CI, 0.26 - 0.87; P = 0.02). Conclusions: Digital TIL quantification with use of machine learning is feasible. TIL levels appear to be a robust and independent biomarker of likelihood of response to IO treatment in NSCLC, especially in the PD-L1 negative subgroup. The findings of this study are under validation in additional lung cancer cohorts.

Background: Circadian rhythms are 24-hour cycles that are part of our body’s internal clock. These processes rely on a transcription-translation feedback loop controlled by a family of circadian-relevant genes, including the transcription factors (CLOCK/BMAL1) and key circadian genes (Cryptochromes (CRY1 and CRY2) and Period (PER1, PER2, and PER3)). Previous studies showed that the circadian clock could affect the DNA damage response pathway. Therefore, we hypothesized that alterations of the circadian clock genes might associate with tumor mutation burden (TMB). Here, we explored the associations of mutations in the circadian clock genes with TMB and response to immune-checkpoint inhibitors (ICIs) in NSCLC. Methods: The ICIs treatment NSCLC cohort from the Memorial Sloan Kettering Cancer Center (MSKCC) was used for exploring the associations of mutations in the clock genes (CLOCK, BMAL1, CRY1, CRY2, PER1, PER2, and PER3) with TMB, tumor neoantigen burden (TNB), and ICIs efficacy. The relationships between the clock genes mutations and TMB, PD-L1 expression, levels of tumor infiltrating lymphocytes (TILs), and prognostic value were investigated in the TCGA-NSCLC cohort. Results: In the TCGA-NSCLC cohort, the most frequently mutated gene was PER3 (1.4%), followed by PER1 (1.3%), CRY1 (1.1%), and CRY2 (0.7%). The median TMB was significantly higher in the clock genes mutations (MT) group compared to the wild type (WT) group (10.1 vs 5.9 muts/Mb, P &amp;lt; 0.0001). However, the data revealed that PD-L1 expression and the levels of TILs did not have any associations with mutations of the clock genes. Furthermore, there was no difference in overall survival (OS) for patients with MT or WT tumors. In the MSKCC ICIs cohort, mutations in the clock genes were also associated with higher TMB (16.7 vs 4.3 muts/Mb, P &amp;lt; 0.0001) and higher median predicted neoantigen burden (1338 vs 293, P &amp;lt; 0.0001). Compared to the WT group, patients in the MT group had a significantly longer median progression-free survival (PFS) (23.0 vs 5.2 months, HR: 0.45 [95%CI: 0.25-0.81], P = 0.0216) with PD-1 plus CTLA-4 blockade. About (70.6%) showed a durable clinical benefit (DCB) in the MT group, while 43.1% of patients showed DCB in the WT group (P = 0.046). Conclusions: Our data indicated that mutations in the clock genes were associated with higher TMB and improved clinical outcomes in NSCLC patients treated with ICIs, suggesting that these mutations might be a potential predictive biomarker for ICIs treatment in NSCLC. However, they did not have significant prognostic value. Citation Format: Dong-Dong Jia, Yanling Niu, Xin Zhang, Tonghui Ma. Alterations of the circadian clock genes and their association with tumor mutation burden and response to immunotherapy in 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 5197.

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.

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...

In an exploratory analysis, we investigated the association between programmed death ligand 1 (PD-L1), tumor mutational burden (TMB), T-cell-inflamed gene expression profile (TcellinfGEP), and stromal signature with outcomes of pembrolizumab in urothelial carcinoma (UC). Patients with advanced UC received first-line pembrolizumab 200 mg every 3 weeks in the single-arm phase II KEYNOTE-052 trial (NCT02335424) and salvage pembrolizumab 200 mg every 3 weeks or chemotherapy (paclitaxel/docetaxel/vinflunine) in the randomized phase III KEYNOTE-045 trial (NCT02256436). The association of each biomarker (continuous variable) with objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) was evaluated using logistic regression (ORR) and Cox PH (PFS, OS), adjusted for ECOG PS; nominal P values were calculated without multiplicity adjustment (one-sided, pembrolizumab; two-sided, chemotherapy). Significance was prespecified at α = 0.05. In KEYNOTE-052, PD-L1, TMB, and TcellinfGEP were significantly associated with improved outcomes; stromal signature was significantly associated with worse outcomes. In KEYNOTE-045, although findings for TMB and TcellinfGEP with pembrolizumab were consistent with those of KEYNOTE-052, PD-L1 was not significantly associated with improved outcomes, nor was stromal signature associated with worse outcomes with pembrolizumab; chemotherapy was not associated with outcomes in a consistent manner for any of the biomarkers. Hazard ratio (HR) estimates at prespecified cutoffs showed an advantage for pembrolizumab versus chemotherapy regardless of PD-L1 or TMB, with a trend toward lower HRs in the combined positive score ≥10 and the TMB ≥175 mutation/exome subgroup. For TcellinfGEP, PFS and OS HRs were lower in the TcellinfGEP-nonlow subgroup regardless of treatment. Multiple biomarkers characterizing the tumor microenvironment may help predict response to pembrolizumab monotherapy in UC, and potential clinical utility of these biomarkers may be context-dependent.

&lt;div&gt;AbstractPurpose:&lt;p&gt;In an exploratory analysis, we investigated the association between programmed death ligand 1 (PD-L1), tumor mutational burden (TMB), T-cell–inflamed gene expression profile (Tcell&lt;sub&gt;inf&lt;/sub&gt;GEP), and stromal signature with outcomes of pembrolizumab in urothelial carcinoma (UC).&lt;/p&gt;Patients and Methods:&lt;p&gt;Patients with advanced UC received first-line pembrolizumab 200 mg every 3 weeks in the single-arm phase II KEYNOTE-052 trial (NCT02335424) and salvage pembrolizumab 200 mg every 3 weeks or chemotherapy (paclitaxel/docetaxel/vinflunine) in the randomized phase III KEYNOTE-045 trial (NCT02256436). The association of each biomarker (continuous variable) with objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) was evaluated using logistic regression (ORR) and Cox PH (PFS, OS), adjusted for ECOG PS; nominal &lt;i&gt;P&lt;/i&gt; values were calculated without multiplicity adjustment (one-sided, pembrolizumab; two-sided, chemotherapy). Significance was prespecified at &lt;i&gt;α&lt;/i&gt; = 0.05.&lt;/p&gt;Results:&lt;p&gt;In KEYNOTE-052, PD-L1, TMB, and Tcell&lt;sub&gt;inf&lt;/sub&gt;GEP were significantly associated with improved outcomes; stromal signature was significantly associated with worse outcomes. In KEYNOTE-045, although findings for TMB and Tcell&lt;sub&gt;inf&lt;/sub&gt;GEP with pembrolizumab were consistent with those of KEYNOTE-052, PD-L1 was not significantly associated with improved outcomes, nor was stromal signature associated with worse outcomes with pembrolizumab; chemotherapy was not associated with outcomes in a consistent manner for any of the biomarkers. Hazard ratio (HR) estimates at prespecified cutoffs showed an advantage for pembrolizumab versus chemotherapy regardless of PD-L1 or TMB, with a trend toward lower HRs in the combined positive score ≥10 and the TMB ≥175 mutation/exome subgroup. For Tcell&lt;sub&gt;inf&lt;/sub&gt;GEP, PFS and OS HRs were lower in the Tcell&lt;sub&gt;inf&lt;/sub&gt;GEP-nonlow subgroup regardless of treatment.&lt;/p&gt;Conclusions:&lt;p&gt;Multiple biomarkers characterizing the tumor microenvironment may help predict response to pembrolizumab monotherapy in UC, and potential clinical utility of these biomarkers may be context-dependent.&lt;/p&gt;&lt;/div&gt;

&lt;div&gt;AbstractPurpose:&lt;p&gt;In an exploratory analysis, we investigated the association between programmed death ligand 1 (PD-L1), tumor mutational burden (TMB), T-cell–inflamed gene expression profile (Tcell&lt;sub&gt;inf&lt;/sub&gt;GEP), and stromal signature with outcomes of pembrolizumab in urothelial carcinoma (UC).&lt;/p&gt;Patients and Methods:&lt;p&gt;Patients with advanced UC received first-line pembrolizumab 200 mg every 3 weeks in the single-arm phase II KEYNOTE-052 trial (NCT02335424) and salvage pembrolizumab 200 mg every 3 weeks or chemotherapy (paclitaxel/docetaxel/vinflunine) in the randomized phase III KEYNOTE-045 trial (NCT02256436). The association of each biomarker (continuous variable) with objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) was evaluated using logistic regression (ORR) and Cox PH (PFS, OS), adjusted for ECOG PS; nominal &lt;i&gt;P&lt;/i&gt; values were calculated without multiplicity adjustment (one-sided, pembrolizumab; two-sided, chemotherapy). Significance was prespecified at &lt;i&gt;α&lt;/i&gt; = 0.05.&lt;/p&gt;Results:&lt;p&gt;In KEYNOTE-052, PD-L1, TMB, and Tcell&lt;sub&gt;inf&lt;/sub&gt;GEP were significantly associated with improved outcomes; stromal signature was significantly associated with worse outcomes. In KEYNOTE-045, although findings for TMB and Tcell&lt;sub&gt;inf&lt;/sub&gt;GEP with pembrolizumab were consistent with those of KEYNOTE-052, PD-L1 was not significantly associated with improved outcomes, nor was stromal signature associated with worse outcomes with pembrolizumab; chemotherapy was not associated with outcomes in a consistent manner for any of the biomarkers. Hazard ratio (HR) estimates at prespecified cutoffs showed an advantage for pembrolizumab versus chemotherapy regardless of PD-L1 or TMB, with a trend toward lower HRs in the combined positive score ≥10 and the TMB ≥175 mutation/exome subgroup. For Tcell&lt;sub&gt;inf&lt;/sub&gt;GEP, PFS and OS HRs were lower in the Tcell&lt;sub&gt;inf&lt;/sub&gt;GEP-nonlow subgroup regardless of treatment.&lt;/p&gt;Conclusions:&lt;p&gt;Multiple biomarkers characterizing the tumor microenvironment may help predict response to pembrolizumab monotherapy in UC, and potential clinical utility of these biomarkers may be context-dependent.&lt;/p&gt;&lt;/div&gt;

Biomarkers that can predict response to anti-programmed cell death 1 (PD-1) therapy across multiple tumor types include a T-cell-inflamed gene-expression profile (GEP), programmed death ligand 1 (PD-L1) expression, and tumor mutational burden (TMB). Associations between these biomarkers and the clinical efficacy of pembrolizumab were evaluated in a clinical trial that encompassed 20 cohorts of patients with advanced solid tumors. KEYNOTE-028 ( ClinicalTrials.gov identifier: NCT02054806) is a nonrandomized, phase Ib trial that enrolled 475 patients with PD-L1-positive advanced solid tumors who were treated with pembrolizumab 10 mg/kg every 2 weeks for 2 years or until confirmed disease progression or unacceptable toxicity occurred. The primary end point was objective response rate (ORR; by RECIST v1.1, investigator review). Secondary end points included safety, progression-free survival (PFS), and overall survival (OS). Relationships between T-cell-inflamed GEP, PD-L1 expression, and TMB and antitumor activity were exploratory end points. ORRs (with 95% CIs) ranged from 0% (0.0% to 14.2%) in pancreatic cancer to 33% (15.6% to 55.3%) in small-cell lung cancer. Across cohorts, median (95% CI) PFS ranged from 1.7 months (1.5 to 2.9 months) to 6.8 months (1.9 to 14.1 months) in pancreatic and thyroid cancers, respectively, and median OS from 3.9 months (2.8 to 5.5 months) to 21.1 months (9.1 to 22.4 months) in vulvar and carcinoid tumors, respectively. Higher response rates and longer PFS were demonstrated in tumors with higher T-cell-inflamed GEP, PD-L1 expression, and/or TMB. Correlations of TMB with GEP and PD-L1 were low. Response patterns indicate that patients with tumors that had high levels of both TMB and inflammatory markers (GEP or PD-L1) represent a population with the highest likelihood of response. Safety was similar and consistent with prior pembrolizumab reports. A T-cell--inflamed GEP, PD-L1 expression, and TMB predicted response to pembrolizumab in multiple tumor types. These biomarkers (alone/in combination) may help identify patients who have a higher likelihood of response to anti-PD-1 therapies across a broad spectrum of cancers.

Purpose Data suggest that TMB is correlated with response to checkpoint blockade. We present an analysis of atezolizumab treatment of patients (pts) with advanced solid tumors and high TMB from MyPathway (NCT02091141), a multi-basket study assessing activity of FDA-approved therapies in non-indicated tumors with targetable alterations. Methods Eligible pts were ≥18 years old with previously treated advanced solid tumors with TMB ≥10 mut/Mb by any CLIA-certified assay. Pts received atezolizumab 1200 mg IV q3w. The pre-planned primary endpoint was objective response rate (ORR) in pts with TMB ≥16 mut/Mb by FoundationOne CDx (F1CDx), a threshold determined by a retrospective study that showed TMB ≥16 mut/Mb is associated with improved ORR and duration of response (DOR) for various tumor types. Other endpoints in this group included disease control rate (DCR), DOR, progression-free survival (PFS), and overall survival (OS). Separate analyses were performed in pts with TMB ≥10 and &amp;lt;16 mut/Mb by F1CDx, and TMB by any CLIA assay. Results Enrollment closed on 7-9-20. By the 12-11-20 data cutoff, 118 pts with 20 tumor types and TMB ≥10 mut/Mb by any CLIA assay were evaluable for efficacy. In the primary efficacy population of 42 pts with TMB ≥16 mut/Mb by F1CDx, confirmed investigator-assessed ORR was 38.1% vs 2.1% in 48 pts with TMB ≥10 mut/Mb and &amp;lt;16 mut/Mb; median DOR was not reached in either group. DCR was 61.9% vs 22.9%, respectively; median PFS was 5.7 vs 1.8 mos; and median OS was 13.7 vs 11.4 mos. In pts with TMB ≥16 mut/Mb by any CLIA assay, ORR was 28.6% and DCR was 55.4%. Responses were observed in diverse tumor types. In pts with TMB ≥16 mut/Mb tumors by F1CDx, those with high microsatellite instability (MSI) had an ORR of 54.5% vs 30.0% for microsatellite stable/low tumors. Conclusions Atezolizumab had durable activity against diverse solid tumor types with TMB ≥16 mut/Mb, independent of MSI status. Limited activity was observed in tumors with TMB ≥10 and &amp;lt;16 mut/Mb. Clinical outcomesSubgroupORRaDCRbDORPFSOSn (%)n (%)Median mosMedian mosMedian mos95% CI95% CI95% CI95% CI95% CITMB by F1CDx assayc≥16 mut/Mb (n=42)16d (38.1)26 (61.9)Not reachede5.713.723.6-54.445.6-76.42.7-9.911.9-NA≥10 and &amp;lt;16 mut/Mb (n=48)1 (2.1)11 (22.9)Not reached1.811.40.1-11.112.0-37.31.4-2.65.3-15.7TMB by any CLIA assayf≥16 mut/Mb (n=56)16d (28.6)31 (55.4)12.24.813.717.3-42.241.5-68.74.4-NA2.6-5.811.9-NA≥10 and &amp;lt;16 mut/Mb (n=62)2 (3.2)13 (21.0)3.51.410.70.4-11.211.7-33.20.7-3.51.4-2.65.3-14.9TMB by F1CDx + MSI statusgTMB ≥16 mut/Mb + MSI-H (n=11)6h (54.5)8 (72.7)Not reached8.3Not reached23.4-83.339.0-94.06.9-NA1.3-NA10.4-NATMB ≥16 mut/Mb + MSS/Li (n=30)9j (30.0)17 (56.7)8.45.612.614.7-49.437.4-74.52.0-NA1.4-8.511.1-NATMB ≥10 and &amp;lt;16 mut/Mb + MSS/Li (n=45)1 (2.2)10 (22.2)Not reached1.811.40.1-11.811.2-37.11.9-NA1.4-2.65.3-15.7Tumor types represented in the safety population with any TMB CLIA assay (n=119) were colon (n=31), breast (n=29), biliary tract (n=6), uterine (n=6), gastroesophageal (n=5), ovarian (n=5), head and neck (n=5), cervical (n=4), prostate (n=4), sarcoma (n=3), urothelial (n=3), lung (n=3), pancreatic (n=3), small bowel (n=3), carcinoma of unknown primary (n=3), pancreatic endocrine (n=2), adrenocortical (n=1), central nervous system (n=1), liver (n=1), and skin (n=1).aIncludes patients with complete or partial response.bIncludes patients with complete or partial response, or stable disease &amp;gt;4 months.cIncludes local F1CDx (n=68) and central F1CDx (n=39); upon central retesting, 17 patients fell below the TMB threshold of 10 mut/Mb required for inclusion in the efficacy analysis.dIncludes three patients with a complete response.eDOR was &amp;gt;15 months in &amp;gt;50% of responders.fIncludes local F1CDx (n=68) and other local CLIA assays (n=51) from the safety population. One patient had no tumor assessment and was not included in the efficacy analysis population.gMSI status was missing for one patient with TMB ≥16 mut/Mb and two patients with TMB ≥10 and &amp;lt;16 mut/Mb. One additional patient with TMB ≥10 and &amp;lt;16 mut/Mb + MSI-H is not shown.hIncludes one patient with a complete response.iMSS/L includes microsatellite stable, low, or intermediate tumors, which were classified as “not high”.jIncludes two patients with a complete response.CI, confidence interval; CLIA, Clinical Laboratory Improvement Amendments; DCR, disease control rate; DOR, duration of response; F1CDx, FoundationOne CDx; MSI-H, high microsatellite instability; MSS/L, microsatellite stable/low; NA, not available; ORR, objective response rate; OS, overall survival; PFS, progression-free survival; TMB, tumor mutational burden.JH and CL contributed equally to this work. Citation Format: John Hainsworth, Claire F. Friedman, Razelle Kurzrock, David R. Spigel, Howard Burris, Christopher J. Sweeney, Funda Meric-Bernstam, Yong Wang, Jonathan Levy, David Shames, Katja Schulze, Arisha Patel, Charles Swanton. Efficacy of atezolizumab in the treatment of solid tumors with high tumor mutational burden (TMB): A MyPathway study cohort [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB012.

BackgroundHigh tumor mutational burden (TMB) and PD-L1 expression are associated with improved clinical outcomes in patients (pts) with non-small cell lung cancer (NSCLC) treated with immune checkpoint inhibitors (ICIs). However,...

The beneficial role of immunotherapy and the clinical relevance of current biomarkers in non-small cell lung cancer (NSCLC) remain inconclusive; thus, appropriate strategies and reliable predictors need further definition. To evaluate the association of clinical outcomes with immune checkpoint inhibitors, tumor vaccines, and cellular immunotherapy in patients with advanced NSCLC and to explore appropriate strategies, candidates, and predictors. The PubMed, EMBASE, and Cochrane Central Register of Controlled Trials databases were searched from inception to June 2018, using relevant search keywords and Medical Subject Headings (MeSH) terms, including tumor vaccine, cellular immunotherapy, immune checkpoint inhibitor, cytotoxic T-lymphocyte-associated protein 4, programmed death-ligand 1, programmed death receptor 1, and non-small cell lung carcinoma. Systematic reviews, meta-analyses, references, and conference proceedings were manually searched. English-language randomized clinical trials with available data that measured overall survival (OS), progression-free survival (PFS), or objective response rate comparing immune checkpoint inhibitors, tumor vaccines, or cellular immunotherapy with conventional therapy for patients with advanced or metastatic NSCLC were included. Thirty-one immunotherapy randomized clinical trials were included, and multicohort data included next-generation sequencing data from patients with advanced NCSLC. Hazard ratios and 95% CIs were pooled to estimate the survival increases in OS and PFS. Dichotomous data, such as object response rate data, were analyzed using the risk ratio. Mantel-Haenszel random-effects model was used. I2 was used to assess the heterogeneity between trials; an I2 value exceeding 50% indicated the existence of substantial heterogeneity. Analyses took place from February 1, 2018, to August 31, 2018. Primary outcomes were OS and PFS. In total, 14 395 patients (9500 [66.0%] men) were included in the meta-analysis, and 1833 patients (mean [SD], 65.2 [9.9] years; 1063 [58.0%] men) were included in the individual patient-level study. Compared with conventional therapy, immunotherapy was associated with significantly longer OS (hazard ratio, 0.76; 95% CI, 0.71-0.82; P < .001) and PFS (hazard ratio, 0.76; 95% CI, 0.70-0.83; P < .001). The best checkpoint blockade strategy was first-line pembrolizumab with platinum-based chemotherapy. The combined predictive utility of programmed cell death ligand 1 (PD-L1) expression and tumor mutation burden (TMB) was associated with predictive prognosis (whole-exome sequencing: 1-year PFS area under the receiver operating characteristic curve [AUC], 0.829; 3-year PFS AUC, 0.839; targeted next-generation sequencing: 1-year PFS AUC, 0.826; 3-year PFS AUC, 0.948). Moreover, the addition of CD8+ T-cell tumor-infiltrating lymphocytes was associated with improved prognosis predictions for OS (3-year OS AUC, 0.659; 5-year OS AUC, 0.665). RYR1 or MGAM mutations were significantly associated with concomitantly increased durable clinical benefits (RYR1: durable clinical benefit [DCB], 12 of 51 patients [24%]; no durable benefit [NDB], 2 of 55 patients [4%]; P < .001; MGAM: DCB, 12 of 51 patients [24%]; NDB, 0 patients; P < .001), a higher TMB (RYRI: high TMB, 12 of 53 patients [23%]; low TMB, 2 of 53 patients [38%]; P < .001; MGAM: high TMB, 9 of 53 patients [17%]; low TMB, 0 patients; P < .001), and higher PD-L1 expression (RYRI: high PD-L1 expression, 8 of 30 patients [27%]; low PD-L1 expression, 6 of 85 [7.1%]; P < .001; MGAM: high PD-L1 expression, 6 of 30 patients [20%]; low PD-L1 expression, 5 of 85 patients [6%]; P < .001). Immunotherapies showed promising clinical outcomes for patients with NSCLC. Pembrolizumab with platinum-based chemotherapy was found to be the most appropriate first-line immune checkpoint inhibitor regimen for advanced NSCLC, and the combined use of PD-L1 expression and TMB was found to be a promising biomarker to evaluate patients' survival and response to precision immunotherapy. The further combination of CD8+ T-cell tumor-infiltrating lymphocytes, PD-L1 expression, and TMB was associated with reliable prognosis. The predictive value of that combination needs to be prospectively validated in large-scale studies.