Genomic and Immunophenotypic Landscape of Acquired Resistance to PD-(L)1 Blockade in Non-Small-Cell Lung Cancer

PURPOSE

Although immune checkpoint inhibitors (ICI) have extended survival in patients with non-small-cell lung cancer (NSCLC), acquired resistance (AR) to ICI frequently develops after an initial benefit. However, the mechanisms of AR to ICI in NSCLC are largely unknown.

METHODS

Comprehensive tumor genomic profiling, machine learning-based assessment of tumor-infiltrating lymphocytes, multiplexed immunofluorescence, and/or HLA-I immunohistochemistry (IHC) were performed on matched pre- and post-ICI tumor biopsies from patients with NSCLC treated with ICI at the Dana-Farber Cancer Institute who developed AR to ICI. Two additional cohorts of patients with intervening chemotherapy or targeted therapies between biopsies were included as controls.

RESULTS

We performed comprehensive genomic profiling and immunophenotypic characterization on samples from 82 patients with NSCLC and matched pre- and post-ICI biopsies and compared findings with a control cohort of patients with non-ICI intervening therapies between biopsies (chemotherapy, N = 32; targeted therapies, N = 89; both, N = 17). Putative resistance mutations were identified in 27.8% of immunotherapy-treated cases and included acquired loss-of-function mutations in STK11, B2M, APC, MTOR, KEAP1, and JAK1/2; these acquired alterations were not observed in the control groups. Immunophenotyping of matched pre- and post-ICI samples demonstrated significant decreases in intratumoral lymphocytes, CD3e+ and CD8a+ T cells, and PD-L1-PD1 engagement, as well as increased distance between tumor cells and CD8+PD-1+ T cells. There was a significant decrease in HLA class I expression in the immunotherapy cohort at the time of AR compared with the chemotherapy (P = .005) and the targeted therapy (P = .01) cohorts.

CONCLUSION

These findings highlight the genomic and immunophenotypic heterogeneity of ICI resistance in NSCLC, which will need to be considered when developing novel therapeutic strategies aimed at overcoming resistance.

Activating point mutations in the MET kinase domain represent a unique molecular subset of lung cancer and other malignancies targetable with MET inhibitors

Activating point mutations in the MET tyrosine kinase domain (TKD) are oncogenic in a subset of papillary renal cell carcinomas (PRCC). Here, using comprehensive genomic profiling among >600,000 patients, we identify activating MET TKD point mutations as putative oncogenic driver across diverse cancers, with a frequency of ~0.5%. The most common mutations in the MET TKD defined as oncogenic or likely oncogenic according to OncoKB resulted in amino acid substitutions at positions H1094, L1195, F1200, D1228, Y1230, M1250, and others. Preclinical modeling of these alterations confirmed their oncogenic potential, and also demonstrated differential patterns of sensitivity to type I and type II MET inhibitors. Two patients with metastatic lung adenocarcinoma harboring MET TKD mutations (H1094Y, F1200I) and no other known oncogenic drivers achieved confirmed partial responses to a type I MET inhibitor. Activating MET TKD mutations occur in multiple malignancies and may confer clinical sensitivity to currently available MET inhibitors.

Impact of Aneuploidy and Chromosome 9p Loss on Tumor Immune Microenvironment and Immune Checkpoint Inhibitor Efficacy in NSCLC

INTRODUCTION

Although gene-level copy number alterations have been studied as a potential biomarker of immunotherapy efficacy in NSCLC, the impact of aneuploidy burden and chromosomal arm-level events on immune checkpoint inhibitor (ICI) efficacy in NSCLC is uncertain.

METHODS

Patients who received programmed cell death protein 1 or programmed death-ligand 1 (PD-L1) inhibitor at two academic centers were included. Across all 22 chromosomes analyzed, an arm was considered altered if at least 70% of its territory was either gained or deleted. Among nonsquamous NSCLCs which underwent targeted next-generation sequencing, we retrospectively quantified aneuploidy using the adjusted fraction of chromosomal arm alterations (FAA), defined as the number of altered chromosome arms divided by the number of chromosome arms assessed, adjusted for tumor purity.

RESULTS

Among 2293 nonsquamous NSCLCs identified, the median FAA increased with more advanced cancer stage and decreased with higher PD-L1 tumor proportion score (TPS) levels (median FAA in TPS < 1%: 0.09, TPS 1%-49%: 0.08, TPS ≥ 50%: 0.05, p < 0.0001). There was a very weak correlation between FAA and tumor mutational burden when taken as continuous variables (R: 0.07, p = 0.0005). A total of 765 advanced nonsquamous NSCLCs with available FAA values were treated with ICIs. With decreasing FAA tertiles, there was a progressive improvement in objective response rate (ORR 15.1% in upper tertile versus 23.2% in middle tertile versus 28.4% in lowest tertile, p = 0.001), median progression-free survival (mPFS 2.5 versus 3.3 versus 4.1 mo, p < 0.0001), and median overall survival (mOS 12.5 versus 13.9 versus 16.4 mo, p = 0.006), respectively. In the arm-level enrichment analysis, chromosome 9p loss (OR = 0.22, Q = 0.0002) and chromosome 1q gain (OR = 0.43, Q = 0.002) were significantly enriched in ICI nonresponders after false discovery rate adjustment. Compared with NSCLCs without chromosome 9p loss (n = 452), those with 9p loss (n = 154) had a lower ORR (28.1% versus 7.8%, p < 0.0001), a shorter mPFS (4.1 versus 2.3 mo, p < 0.0001), and a shorter mOS (18.0 versus 9.6 mo, p < 0.0001) to immunotherapy. In addition, among NSCLCs with high PD-L1 expression (TPS ≥ 50%), chromosome 9p loss was associated with lower ORR (43% versus 6%, p < 0.0001), shorter mPFS (6.4 versus 2.6 mo, p = 0.0006), and shorter mOS (30.2 versus 14.3 mo, p = 0.0008) to immunotherapy compared with NSCLCs without 9p loss. In multivariable analysis, adjusting for key variables including FAA, chromosome 9p loss, but not 1q gain, retained a significant impact on ORR (hazard ratio [HR] = 0.25, p < 0.001), mPFS (HR = 1.49, p = 0.001), and mOS (HR = 1.47, p = 0.003). Multiplexed immunofluorescence and computational deconvolution of RNA sequencing data revealed that tumors with either high FAA levels or chromosome 9p loss had significantly fewer tumor-associated cytotoxic immune cells.

CONCLUSIONS

Nonsquamous NSCLCs with high aneuploidy and chromosome 9p loss have a distinct tumor immune microenvironment and less favorable outcomes to ICIs.

Advanced non-small-cell lung cancer treated with first-line pembrolizumab plus chemotherapy: tumor response dynamics as a marker for survival

OBJECTIVES

The study investigated tumor burden dynamics on computed tomography (CT) scans in patients with advanced non-small-cell lung cancer (NSCLC) during first-line pembrolizumab plus chemotherapy, to provide imaging markers for overall survival (OS).

METHODS

The study included 133 patients treated with first-line pembrolizumab plus platinum-doublet chemotherapy. Serial CT scans during therapy were assessed for tumor burden dynamics during therapy, which were studied for the association with OS.

RESULTS

There were 67 responders, with overall response rate of 50%. The tumor burden change at the best overall response ranged from - 100.0% to + 132.1% (median of - 30%). Higher response rates were associated with younger age (p < 0.001) and higher programmed cell death-1 (PD-L1) expression levels (p = 0.01). Eighty-three patients (62%) showed tumor burden below the baseline burden throughout therapy. Using an 8-week landmark analysis, OS was longer in patients with tumor burden below the baseline burden in the first 8 weeks than in those who experienced ≥ 0% increase (median OS: 26.8 vs. 7.6 months, hazard ratio (HR): 0.36, p < 0.001). Tumor burden remained below their baseline throughout therapy was associated with significantly reduced hazards of death (HR: 0.72, p = 0.03) in the extended Cox models, after adjusting for other clinical variables. Pseudoprogression was noted in only one patient (0.8%).

CONCLUSIONS

Tumor burden staying below the baseline burden throughout the therapy was predictive of prolonged overall survival in patients with advanced NSCLC treated with first-line pembrolizumab plus chemotherapy, and may be used as a practical marker for therapeutic decisions in this widely used combination regimen.

CLINICAL RELEVANCE STATEMENT

The analysis of tumor burden dynamics on serial CT scans in reference to the baseline burden can provide an additional objective guide for treatment decision making in patients treated with first-line pembrolizumab plus chemotherapy for their advanced NSCLC.

KEY POINTS

• Tumor burden remaining below baseline burden during therapy predicted longer survival during first-line pembrolizumab plus chemotherapy. • Pseudoprogression was noted in 0.8%, demonstrating the rarity of the phenomenon. • Tumor burden dynamics may serve as an objective marker for treatment benefit to guide treatment decisions during first-line pembrolizumab plus chemotherapy.

Clinicopathologic, Genomic, and Immunophenotypic Landscape of ATM Mutations in Non-Small Cell Lung Cancer

PURPOSE

ATM is the most commonly mutated DNA damage and repair gene in non-small cell lung cancer (NSCLC); however, limited characterization has been pursued.

EXPERIMENTAL DESIGN

Clinicopathologic, genomic, and treatment data were collected for 5,172 patients with NSCLC tumors which underwent genomic profiling. ATM IHC was performed on 182 NSCLCs with ATM mutations. Multiplexed immunofluorescence was performed on a subset of 535 samples to examine tumor-infiltrating immune cell subsets.

RESULTS

A total of 562 deleterious ATM mutations were identified in 9.7% of NSCLC samples. ATM-mutant (ATMMUT) NSCLC was significantly associated with female sex (P = 0.02), ever smoking status (P < 0.001), non-squamous histology (P = 0.004), and higher tumor mutational burden (DFCI, P < 0.0001; MSK, P < 0.0001) compared with ATM-wild-type (ATMWT) cases. Among 3,687 NSCLCs with comprehensive genomic profiling, co-occurring KRAS, STK11, and ARID2 oncogenic mutations were significantly enriched among ATMMUT NSCLCs (Q < 0.05), while TP53 and EGFR mutations were enriched in ATMWT NSCLCs. Among 182 ATMMUT samples with ATM IHC, tumors with nonsense, insertions/deletions, or splice site mutations were significantly more likely to display ATM loss by IHC (71.4% vs. 28.6%; P < 0.0001) compared with tumors with only predicted pathogenic missense mutations. Clinical outcomes to PD-(L)1 monotherapy (N = 1,522) and chemo-immunotherapy (N = 951) were similar between ATMMUT and ATMWT NSCLCs. Patients with concurrent ATM/TP53 mutations had significantly improved response rate and progression-free survival with PD-(L)1 monotherapy.

CONCLUSIONS

Deleterious ATM mutations defined a subset of NSCLC with unique clinicopathologic, genomic, and immunophenotypic features. Our data may serve as resource to guide interpretation of specific ATM mutations in NSCLC.

Clinicopathologic and Genomic Factors Impacting Efficacy of First-Line Chemoimmunotherapy in Advanced NSCLC

INTRODUCTION

Although programmed cell death protein 1 and programmed death-ligand 1 (PD-L1) blockade in combination with platinum-doublet chemotherapy has become a mainstay of first-line treatment for advanced NSCLC, factors associated with efficacy of chemoimmunotherapy (CIT) are not well characterized.

METHODS

In this multicenter retrospective analysis, clinicopathologic and genomic data were collected from patients with advanced NSCLC (lacking sensitizing genomic alterations in EGFR and ALK) and evaluated with clinical outcomes to first-line CIT.

RESULTS

Among 1285 patients treated with CIT, a worsening performance status and increasing derived neutrophil-to-lymphocyte ratio in the blood were associated with a significantly reduced objective response rate (ORR), median progression-free survival (mPFS), and median overall survival (mOS). With increasing PD-L1 tumor proportion scores of less than 1%, 1% to 49%, 50% to 89%, and greater than or equal to 90%, there was a progressive improvement in ORR (32.7% versus 37.5% versus 51.6% versus 61.7%, p < 0.001), mPFS (5.0 versus 6.1 versus 6.8 versus 13.0 mo, p < 0.001), and generally mOS (12.9 versus 14.6 versus 34.7 versus 23.1 mo, p = 0.009), respectively. Of 789 NSCLCs with comprehensive genomic data, NSCLCs with a tumor mutational burden (TMB) greater than or equal to the 90th percentile had an improved ORR (53.5% versus 36.4%, p = 0.004), mPFS (10.8 versus 5.5 mo, p < 0.001), and mOS (29.2 versus 13.1 mo, p < 0.001), compared with those with a TMB less than the 90th percentile. In all-comers with nonsquamous NSCLC, the presence of an STK11, KEAP1, or SMARCA4 mutation was associated with significantly worse ORR, mPFS, and mOS to CIT (all p < 0.05); this was also observed in the KRAS-mutant subgroup of NSCLCs with co-occurring mutations in STK11, KEAP1, or SMARCA4 (all p < 0.05). In KRAS wild-type NSCLC, KEAP1 and SMARCA4 mutations were associated with a significantly shorter mPFS and mOS to CIT (all p < 0.05), but STK11 mutation status had no significant impact on mPFS (p = 0.16) or mOS (p = 0.38).

CONCLUSIONS

In advanced NSCLC, better patient performance status, low derived neutrophil-to-lymphocyte ratio, increasing PD-L1 expression, a very high TMB, and STK11/KEAP1/SMARCA4 wild-type status are associated with improved clinical outcomes to first-line CIT.

Dissecting the clinicopathologic, genomic, and immunophenotypic correlates of KRASG12D-mutated non-small-cell lung cancer

BACKGROUND

Allele-specific KRAS inhibitors are an emerging class of cancer therapies. KRAS-mutant (KRASMUT) non-small-cell lung cancers (NSCLCs) exhibit heterogeneous outcomes, driven by differences in underlying biology shaped by co-mutations. In contrast to KRASG12C NSCLC, KRASG12D NSCLC is associated with low/never-smoking status and is largely uncharacterized.

PATIENTS AND METHODS

Clinicopathologic and genomic information were collected from patients with NSCLCs harboring a KRAS mutation at the Dana-Farber Cancer Institute (DFCI), Memorial Sloan Kettering Cancer Center, MD Anderson Cancer Center, and Imperial College of London. Multiplexed immunofluorescence for CK7, programmed cell death protein 1 (PD-1), programmed death-ligand 1 (PD-L1), Foxp3, and CD8 was carried out on a subset of samples with available tissue at the DFCI. Clinical outcomes to PD-(L)1 inhibition ± chemotherapy were analyzed according to KRAS mutation subtype.

RESULTS

Of 2327 patients with KRAS-mutated (KRASMUT) NSCLC, 15% (n = 354) harbored KRASG12D. Compared to KRASnon-G12D NSCLC, KRASG12D NSCLC had a lower pack-year (py) smoking history (median 22.5 py versus 30.0 py, P < 0.0001) and was enriched in never smokers (22% versus 5%, P < 0.0001). KRASG12D had lower PD-L1 tumor proportion score (TPS) (median 1% versus 5%, P < 0.01) and lower tumor mutation burden (TMB) compared to KRASnon-G12D (median 8.4 versus 9.9 mt/Mb, P < 0.0001). Of the samples which underwent multiplexed immunofluorescence, KRASG12D had lower intratumoral and total CD8+PD1+ T cells (P < 0.05). Among 850 patients with advanced KRASMUT NSCLC who received PD-(L)1-based therapies, KRASG12D was associated with a worse objective response rate (ORR) (15.8% versus 28.4%, P = 0.03), progression-free survival (PFS) [hazard ratio (HR) 1.51, 95% confidence interval (CI) 1.45-2.00, P = 0.003], and overall survival (OS; HR 1.45, 1.05-1.99, P = 0.02) to PD-(L)1 inhibition alone but not to chemo-immunotherapy combinations [ORR 30.6% versus 35.7%, P = 0.51; PFS HR 1.28 (95%CI 0.92-1.77), P = 0.13; OS HR 1.36 (95%CI 0.95-1.96), P = 0.09] compared to KRASnon-G12D.

CONCLUSIONS

KRASG12D lung cancers harbor distinct clinical, genomic, and immunologic features compared to other KRAS-mutated lung cancers and worse outcomes to PD-(L)1 blockade. Drug development for KRASG12D lung cancers will have to take these differences into account.

Association of High Tumor Mutation Burden in Non-Small Cell Lung Cancers With Increased Immune Infiltration and Improved Clinical Outcomes of PD-L1 Blockade Across PD-L1 Expression Levels

Importance

Although tumor mutation burden (TMB) has been explored as a potential biomarker of immunotherapy efficacy in solid tumors, there still is a lack of consensus about the optimal TMB threshold that best discriminates improved outcomes of immune checkpoint inhibitor therapy among patients with non-small cell lung cancer (NSCLC).

Objectives

To determine the association between increasing TMB levels and immunotherapy efficacy across clinically relevant programmed death ligand-1 (PD-L1) levels in patients with NSCLC.

Design, Setting, and Participants

This multicenter cohort study included patients with advanced NSCLC treated with immunotherapy who received programmed cell death-1 (PD-1) or PD-L1 inhibition in the Dana-Farber Cancer Institute (DFCI), Memorial Sloan Kettering Cancer Center (MSKCC), and in the Stand Up To Cancer (SU2C)/Mark Foundation data sets. Clinicopathological and genomic data were collected from patients between September 2013 and September 2020. Data analysis was performed from November 2021 to February 2022.

Exposures

Treatment with PD-1/PD-L1 inhibition without chemotherapy.

Main Outcomes and Measures

Association of TMB levels with objective response rate (ORR), progression-free survival (PFS), and overall survival (OS).

Results

In the entire cohort of 1552 patients with advanced NSCLC who received PD-1/PD-L1 blockade, the median (range) age was 66 (22-92) years, 830 (53.5%) were women, and 1347 (86.8%) had cancer with nonsquamous histologic profile. A regression tree modeling ORR as a function of TMB identified 2 TMB groupings in the discovery cohort (MSKCC), defined as low TMB (≤19.0 mutations per megabase) and high TMB (>19.0 mutations per megabase), which were associated with increasing improvements in ORR, PFS, and OS in the discovery cohort and in 2 independent cohorts (DFCI and SU2C/Mark Foundation). These TMB levels also were associated with significant improvements in outcomes of immunotherapy in each PD-L1 tumor proportion score subgroup of less than 1%, 1% to 49%, and 50% or higher. The ORR to PD-1/PD-L1 inhibition was as high as 57% in patients with high TMB and PD-L1 expression 50% or higher and as low as 8.7% in patients with low TMB and PD-L1 expression less than 1%. Multiplexed immunofluorescence and transcriptomic profiling revealed that high TMB levels were associated with increased CD8-positive, PD-L1-positive T-cell infiltration, increased PD-L1 expression on tumor and immune cells, and upregulation of innate and adaptive immune response signatures.

Conclusions and Relevance

These findings suggest that increasing TMB levels are associated with immune cell infiltration and an inflammatory T-cell-mediated response, resulting in increased sensitivity to PD-1/PD-L1 blockade in NSCLC across PD-L1 expression subgroups.

Abstract 2143: Clinicopathologic, genomic and immunophenotypic landscape of ATM mutations in non-small cell lung cancer

Introduction: Defective DNA damage repair machinery is a hallmark of cancer, resulting in increased mutation rates and genomic instability. In non-small cell lung cancer (NSCLC), ATM is mutated in ~10% of cases, representing the most commonly mutated DNA damage and repair gene. However, the clinicopathologic, genomic, and immunophenotypic correlates of ATM mutations in NSCLC are unknown. The impact of ATM mutation on clinical outcomes to PD-(L)1 blockade is also unclear.

Methods: Clinicopathologic and genomic data were collected from 3592 patients (pts) with NSCLC who had consented to correlative studies at the Dana-Farber Cancer Institute (DFCI), and whose tumors underwent genomic profiling (OncoPanel). Multiplexed immunofluorescence (mIF) for CD8, PD1, PD-L1, FOXP3, and CK AE1/AE3 was performed on a subset of 416 NSCLC samples to examine tumor-infiltrating immune cells. ATM immunohistochemistry (IHC) was also performed on 184 ATM mutated NSCLCs with available tissue. ATM mutated (ATMMUT) tumors were defined as harboring loss-of-function mutations (nonsense, frameshift, splice site, known deleterious missense mutations). Missense mutation of unknown significance were excluded, unless deemed to affect protein function in silico. Tumors lacking ATM mutations or harboring benign ATM alterations were defined as ATM wild type (ATMWT).

Results: A total of 399 deleterious ATM mutations were identified in 10.2% (365/3592) of samples; 138 (34.6%) mutations were truncating (nonsense, frameshift, and splice site mutations); the remaining 261 (65.4%) were missense mutations. Truncating mutations were significantly more likely to result in ATM loss by IHC compared to missense mutations (71.4% vs 28.9%, P&lt;0.01) When we examined the genomic profiles of tumors with versus without deleterious ATM mutations, we found that ATMMUT NSCLCs were significantly enriched with KRAS, STK11, RBM10, and KDM5C co-mutations (P&lt;0.01), while co-mutations in EGFR, CDKN2A and TP53 were nearly mutually exclusive (P&lt;0.01). Among ATMMUT NSCLCs, those with ATM loss by IHC were significantly enriched with KRAS and STK11 co-mutations, while those with retained ATM expression were enriched with TP53 co-mutations (P&lt;0.01). Pts with ATMMUT NSCLCs had similar outcomes to PD-(L)1 inhibition +/- chemotherapy, compared to ATMWT cases, and similar immune cell subsets infiltration (P&gt;0.05). Pts with deleterious mutations in ATM and TP53 (ATMMUT/TP53MUT) had increased response rates to chemo-immunotherapy compared to those with ATMMUT/TP53WT, ATMWT/TP53MUT, or ATMWT/TP53WT genotypes (70% vs 56.2% vs 35.7% vs 27.4%, respectively, P=0.01), as well as increased tumor-stroma interface CD8+ T cells (P&lt;0.01) and higher PD-L1 expression by mIF on tumor (P&lt;0.01) and immune cells (P&lt;0.01).

Conclusion: Deleterious ATM mutations defined a subset of NSCLC with unique clinicopathologic, genomic, and immunophenotypic features.

Citation Format: Biagio Ricciuti, Joao Victor Alessi, Xinan Wang, Arrien A. Bertram, Victor R. Vaz, Mizuki Nishino, James Lindsay, Kristen D. Felt, Bijaya Sharma, Lynette M. Sholl, Rodig Scott, Mark M. Awad, Michael L. Cheng. Clinicopathologic, genomic and immunophenotypic landscape of ATM mutations in non-small cell lung cancer [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 2143.

Abstract 506: Dissecting the genomic and tumor immune microenvironment factors associated with disease recurrence in resected stage I NSCLC

Background: Patients with early-stage non-small cell lung cancer (NSCLC) are at substantial risk for disease recurrence after surgical resection, and the discovery of biomarkers that predict disease recurrence has been challenging. We sought to identify genomic and immunologic factors associated with recurrence after surgery in stage I NSCLC.

Methods: We collected clinicopathologic data from patients with resected stage I NSCLC (AJCC 8th Edition) which underwent multiplexed immunofluorescence for CD8+, FOXP3+, PD-1+, and PD-L1. A subset of these samples also had next-generation sequencing performed to identify genomic alterations and tumor mutational burden (TMB). A bidirectional stepwise elimination was applied on variables with a univariable disease-free survival (DFS) p-value &lt;0.25. The final multivariable Cox model was validated with internal bootstrapping (B=300).

Results: A total of 252 cases were included. After a median follow-up of 25.6 months from the time of surgery, 47 cases (18.7%) experienced recurrence, with a 2-year DFS rate of 82.9%, and a 2-year overall survival (OS) rate of 97.9%. Shorter DFS was associated with higher TMB, increased PD-L1 expression, and greater numbers of intratumoral (IT) CD8+, PD-1+, and PD-1+CD8+ immune cells, as well as increased CD8+ and FOXP3+ T cells at the tumor stroma interface (TSI) in univariable analyses (p&lt;0.05). Multivariable analysis showed that shorter DFS was associated with increasing TMB and higher PD-L1 tumor cell expression. We observed a difference by immune cell localization and risk of recurrence: shorter DFS was associated with higher IT but lower TSI PD-1+ immune cells, and higher IT but lower TSI FOXP3+ T cells (Table). Internal bootstrap validation showed good model performance (C-index = 0.74).

Conclusion: Genomic analysis and immunophenotyping of stage I NSCLCs can identify cases at greatest risk of disease recurrence after surgical resection.

Table. Univariable and multivariable analysis Disease-free survival Univariable HR [95%CI] p-value Multivariable HR [95%CI] p-value Stage at diagnosis - 0.10 – – IA1 1.52 [0.58, 3.97] IA2 2.61 [0.95, 7.20] IA3 2.61 [1.03, 6.63] IB Histology - 0.42 Adenocarcinoma 1.38 [0.65, 2.97] Squamous Age* 1.02 [0.99, 1.06] 0.19 – – TMB* 1.09 [1.05, 1.12] &lt;0.001 1.09 [1.05, 1.13] &lt;0.001 Smoking* (pack-years) 1.01 [1.00, 1.02] 0.008 – – Smoking history - 0.012 – – Never 5.24 [1.27, 21.7] Former Current 4.92 [0.82, 29.5] Surgical treatment - 0.084 - 0.074 Lobectomy 1.80 [0.89, 3.62] 2.18 [0.93, 5.14] Sublobar Intratumoral** 1.09 [1.03, 1.16] 0.015 - – CD8+ 1.22 [1.10, 1.36] 0.002 1.80 [1.13, 2.87] 0.014 PD-1+ 1.51 [1.20, 1.90] 0.004 - – 0.004 PD-1+ CD8+ 1.22 [1.04, 1.44] 0.053 0.15 [0.04, 0.55] FOXP3+ Tumor-Stroma Interface** 1.06 [1.01, 1.11] 0.033 - - CD8+ 1.10 [1.01,1.20] 0.056 0.71 [0.56, 0.91] 0.007 PD-1+ 1.21 [0.99, 1.48] 0.100 - - PD-1+ CD8+ 1.28 [1.03, 1.59] 0.037 2.42 [1.49, 3.95] &lt;0.001 FOXP3+ PD-L1 expression* 1.02 [1.01, 1.03] &lt;0.001 1.03 [1.01, 1.04] &lt;0.001 Tumor Proportion Score (TPS) 1.02 [1.01, 1.04] - - Immune cells 0.011 *Per unit increase. ** Per 100 units increase. Intratumoral, is defined as the region of the slide consisting of tumor beyond the tumor-stroma interface. Tumor-Stroma Interface is defined as the region within 40 microns to either side of the defined border between tumor and stroma.

Citation Format: Joao Victor Alessi, Zihan Wei, Biagio Ricciuti, James Lindsay, Victor R. Vaz, Adriana Barrichello, Bijaya Sharma, Kristen D. Felt, Fangxin Hong, Lynette M. Sholl, Scott J. Rodig, Mark M. Awad. Dissecting the genomic and tumor immune microenvironment factors associated with disease recurrence in resected stage I 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 506.

Distinct genomic and immunophenotypic features of solid-predominant versus nonsolid-predominant stage I lung adenocarcinomas and association with disease recurrence after surgical resection

8514

Background: Compared to lung adenocarcinomas (LUAD) with nonsolid-predominant histology (lepidic, acinar, papillary, micropapillary), those with predominantly solid features have a higher risk of disease recurrence after surgical resection. However, little is known about the genomic landscape and immunophenotype of solid vs nonsolid stage I LUAD. Methods: We collected clinicopathologic data from patients with resected stage I NSCLC (AJCC 8th Edition), which underwent next-generation sequencing to identify genomic alterations and tumor mutational burden (TMB). A subset of these samples also had multiplexed immunofluorescence for CD8+, FOXP3+, PD-1+, and PD-L1 to determine differences in tumor immune cells subsets according to histologic subtype. Disease free-survival (DFS) was compared in patients based on their predominant histologic subtype (solid vs nonsolid). Results: Among 658 LUADs, 11.4% (N = 75) had solid-predominant and 88.6% (N = 583) nonsolid-predominant histology. After a median follow-up of 50 months from the time of surgery, 145 patients (22.0%) experienced recurrence. Compared to nonsolid-predominant LUAD, those with solid predominance had a significantly lower prevalence of activating EGFR, BRAFV600E, and METex14 mutations as well as ALK/ RET/ ROS1 rearrangements (9.3% versus 31.6%, P < 0.001), no difference in KRASG12C frequency (24% versus 16.8%, P = 0.14), a higher TMB (median 12.2 versus 7.2 mutations/megabase; P < 0.001), and a shorter median DFS from the time of surgical resection (43.2 months versus not reached, HR: 3.3 [95% CI: 2.2-4.9], P < 0.001). The detrimental effect of solid-predominant LUAD in DFS remained significant after adjusting for other factors such as tumor stage, surgery type, smoking status, and TMB (HR: 2.66 [95% CI: 1.71-4.11], P < 0.001]. Among LUADs profiled by multiplex immunofluorescence, compared to tumors with nonsolid-predominant subtype (N = 197), those with solid predominance (N = 23) had significantly higher numbers of CD8+, FOXP3+, PD-1+ immune cells, and PD-1+ CD8+ T cells, both intratumorally (P < 0.001) and at the tumor-stroma interface (P < 0.001). Solid-predominant subtype was also associated with a higher median PD-L1 expression level on tumor (5% versus 1%; P = 0.01) and immune cells (16% versus 7%, P = 0.02). Conclusions: Among patients with surgically-resected stage I LUAD, solid-predominant histology was associated with distinct genotypic and immunologic characteristics. These findings may aid in identifying patients at greater risk of recurrence after surgery.

Impact of STK11 copy loss on clinical outcomes to PD-(L)1 blockade in non–small cell lung cancer

9059

Background: STK11 is among the most commonly altered genes in non-squamous lung cancers. While STK11 mutation is associated with diminished efficacy of immune checkpoint inhibition (ICI), particularly in KRAS mutated tumors, it is not known whether STK11 copy deletion influences outcomes to ICI. Methods: Patients with advanced non-squamous non-small cell lung cancer (NSCLC) treated with ICI whose tumors underwent genomic profiling were included. Clinical outcomes to ICI were analyzed according to KRAS mutation and STK11 deletions. STK11 copy number variations (CNVs) were determined using an internal informatic pipeline. Kaplan-Meier methodology was used to estimate event-time distributions. Results: Of 559 patients with non-squamous NSCLCs (Nsq-NSCLC), 40.4% (N = 226) had a KRAS mutation ( KRASmut), 18.4% (N = 103) had an oncogenic STK11 mutation ( STK11mut), and 22.5% had either single (N = 123), or bi-allelic (N = 3) deletion ( STK11del). Given that 32.5% of STK11del cases had a concurrent oncogenic STK11 mutation in our cohort, to isolate the impact of STK11del on ICI outcomes we excluded samples with STK11mut from this analysis. In all comers with NSCLC, STK11del had no impact on objective response rate (22.2% versus 23.8%, P = 0.8), progression-free (PFS, HR 0.90, P = 0.30), and overall survival (OS, HR 0.96, P = 0.79) to ICI. When we examined the impact of STK11del on clinical outcomes to PD-(L)1 blockade among KRASmut cases we found that STK11del was associated with a numerically lower ORR (13.3% versus 30.0%, P = 0.12), and a significantly shorter PFS (HR 0.57, P = 0.018) compared to cases without STK11del. No difference in OS were observed between these groups (HR 0.77, P = 0.39). Among KRASwt NSCLCs, STK11del cases had a similar ORR (22.6% versus 22.9%, P = 0.99), PFS (HR 0.92, P = 0.63), and OS (HR 1.18, P = 0.32) to PD-(L)1 inhibition compared to cases without STK11del. Among KRASmut but not KRASwt NSCLCs, cases with STK11del had significantly lower PD-L1 expression compared to those without STK11 deletions (27.5% versus 70%, P = 0.01). Conclusions: STK11 deletion is associated with low response rate and short progression-free survival among KRAS mutant NSCLCs. Future analyses will incorporate additional cases to increase sample size and immunopathologic findings to assess impact of mono and bi-allelic deletion on protein expression.

Activating MET kinase domain mutations define a novel molecular subtype of non–small cell lung cancer that is clinically targetable with the MET inhibitor elzovantinib (TPX-0022)

9124

Background: In non-small cell lung cancer (NSCLC), MET exon 14 skipping (METex14) mutations and MET amplification can be targeted with MET inhibitors. Here, we describe a novel, actionable molecular subtype of NSCLC characterized by activating MET-tyrosine kinase domain (MET-TKD) mutations in the absence of METex14 mutations. Methods: Clinicopathologic and genomic data were abstracted from NSCLC cases included in a multi-institutional cohort of tumors that underwent genomic profiling in the GENIE v10, China PanCancer, and the International Cancer Genome Consortium/ The Cancer Genome Atlas (ICGC/TCGA) datasets. External validation of the prevalence of MET-TKD mutations was performed on an independent cohort of NSCLC tissue and liquid samples from the Foundation Medicine genomic database. Results: Among 14,099 NSCLC samples in the multi-institutional cohort, 71 (0.5%) harbored MET-TKD mutations without concurrent METex14 mutations: 55 of these had uncertain pathogenic significance and 16 had known oncogenic potential, including MET H1094Y/R, D1228H/N/V, N1100S, H1106D, V1188I, and M1250T, in order of decreasing prevalence. In a separate cohort of 91,515 NSCLC samples from the Foundation Medicine database, MET-TKD mutations lacking concurrent METex14 mutations were identified in 799 (0.9%) samples, including H1094Y, L1195V, D1228H/N, M1250T and others. Among 60 NSCLC samples harboring MET-TKD mutations without concurrent METex14 mutations with complete genomic data in the multi-institutional cohort, 36 (60%) had concurrent driver alterations in KRAS, EGFR, ROS1, BRAF, HER2, or RET, while 24 (40%) had no concurrent oncogenic drivers. Among patients with available demographic data in the multi-institutional cohort, those with MET-TKD-mutant NSCLC (N = 70) were significantly younger than patients with METex14-mutant NSCLC (N = 353) (median age 63 [range 30-86] vs 73 [range 44-88], p < 0.0001), and there was no significant difference in sex or self-reported race. Confirmed partial responses to the MET tyrosine kinase inhibitor elzovantinib (TPX-0022) were observed in two patients with MET-TKD-mutant NSCLC and no other detectable driver mutations: a 64-year-old man with MET H1094Y-mutant NSCLC, and an 80-year-old man with MET F1200I-mutant NSCLC. Conclusions: Potentially actionable MET-TKD mutations lacking concurrent METex14 mutations represent a novel genomic subtype in 0.5-0.9% of NSCLC, and occur in the absence of other known drivers in a subset of cases.

Immunophenotypic correlates and response to first-line pembrolizumab among elderly patients with PD-L1-high (≥ 50%) non–small cell lung cancer

9054

Background: Older age is associated with increased levels of systemic inflammation and altered immunosurveillance in cancer. Whether aging correlates with a distinct immunophenotype or impacts clinical outcomes to first-line pembrolizumab in patients with advanced non-small-cell lung cancer (NSCLC) and a PD-L1 tumor proportion score (TPS) of ≥50% is unclear. Methods: We performed a retrospective analysis of patients with NSCLC. Multiplexed immunofluorescence (mIF) for CD8+, PD-1+, PD-1+CD8+ and FOXP3+ was performed to explore tumor immunophenotype. Clinical outcomes were analyzed on a separate cohort of patients with PD-L1-high (TPS of ≥50%) NSCLC (negative for sensitizing genomic alterations in EGFR and ALK) who received treatment with first-line pembrolizumab. Variables demonstrating a univariate signal of association of p < 0.1 were included in the multivariate model. The results were compared in patients < 80 vs ≥80 years old. Results: Among 541 patients with NSCLCs profiled by mIF, the median age was 67 (28-90). When comparing patients < 80y (n = 497) to ≥80y (n = 44), there was no difference in median CD8+ T cells/mm2 (171 vs 148; p = 0.69), PD-1+ immune cells/mm2 (81.1 vs 87.2; p = 0.95), or PD-1+CD8+ T cells/mm2 (18.0 vs 13.1; p = 0.56). NSCLCs from patients ≥80y had a higher median of intratumoral-associated FOXP3+ T cells/mm2 (63.6 vs 91.1; p = 0.03). In a cohort of 271 patients with PD-L1 ≥50% who received first-line pembrolizumab, baseline clinicopathological characteristics were balanced in the < 80y (n = 225) vs ≥80y (n = 46) groups in terms of sex, tobacco use, Eastern Cooperative Oncology Group-Performance Status (ECOG-PS), histology, presence of potentially targetable driver mutations (KRAS, MET, BRAF, HER2, RET), and PD-L1 TPS distribution (50-89% vs ≥90%). Compared to patients < 80y, patients ≥80y had no difference in objective response rate (ORR 39.1% vs 28.2%; p = 0.22) or median progression-free survival (mPFS 6.0 vs 3.0 months; p = 0.16). However, patients ≥80y had a shorter median overall survival (mOS 25.7 vs 7.6 months; p = 0.02), and this result remained significant after adjusting for ECOG-PS. Among those who experienced disease progression on pembrolizumab, patients ≥80y were significantly less likely to receive any second-line systemic therapy compared to patients < 80y (55.6% vs 30.8%; p = 0.008). Conclusions: In patients with NSCLC and PD-L1 ≥50%, the ORR and mPFS to first-line pembrolizumab were similar between patients < vs ≥80 years old. OS was shorter among patients ≥80y, potentially reflecting lower use of second-line therapy in elderly patients after progression on pembrolizumab. The immunophenotypic correlates of NSCLC in older patients need further investigation.

Genomic correlates of acquired resistance to PD-(L)1 blockade in patients with advanced non-small cell lung cancer (NSCLC)

9021

Background: Despite improvements in survival with immune checkpoint inhibition (ICI), the majority of patients develop acquired resistance to ICI after an initial benefit. However, the mechanisms underlying acquired resistance to ICI in NSCLC are largely unknown. Methods: Patients with advanced NSCLC treated with ICI at the Dana-Farber Cancer Institute (DFCI), and whose tumors underwent genomic profiling before and after ICI, with no intervening therapies, were included. Mutations, tumor mutational burden (TMB), copy number variations (CNVs), and PD-L1 tumor proportion score (TPS) were compared between pre- and post-ICI samples. Acquired resistance was defined as the development of disease progression after an initial objective response, or stable disease ≥3 months with PD-(L)1 blockade. Results: Among 1763 patients with advanced NSCLC who received ICI, 45 had matched pre- and post-ICI tissue samples available for genomic profiling. Putative mechanisms of resistance were identified in 55% of cases (N = 25). Five patients (20%) acquired an STK11 mutation, one patient (4%) acquired a KEAP1 mutation, and another patient (4%) developed concurrent KEAP1 and SMARCA4 mutations. A patient (4%) with KRAS G12C-mutant NSCLC developed concurrent STK11 and KEAP1 mutations at resistance. In 3 cases (12%) with pre-existing STK11 or KEAP1 mutations prior to ICI administration, we identified acquired copy losses of STK11 and KEAP1, respectively, resulting in bi-allelic inactivation of these genes. Acquired beta-2-microglobulin ( B2M) mutations were detected in 3 patients (12%), one of whom developed concurrent B2M copy loss, indicating bi-allelic inactivation. Eight additional patients (32%) developed B2M gene deletions. Other acquired alterations that have been implicated in ICI resistance included CDKN2A/B loss (N = 10, 40%), including 5 with bi-allelic deletion, acquired PTEN deletions (N = 5, 20%), and MDM2 amplification (N = 2, 8%). When we examined alterations in immune checkpoint genes, we identified acquired CD274 (PD-L1) and PDCD1LG2 (PD-L2) loss in 8% of cases (N = 2), and bi-allelic deletion in one case (4%). Intervening ICI did not affect TMB (median TMB: 8.7 [pre-ICI] vs 9.1 [post-ICI] mut/Mb, P = 0.6), PD-L1 expression (median PD-L1 TPS: 3% [pre-ICI] vs 5.0% [post-ICI] mut/Mb, P = 0.5), or aneuploidy levels (as fraction of genome altered [FGA]) (median FGA: 18.4% [pre-ICI] vs 21.1% [post-ICI], P = 0.2), indicating that acquired gene level CNVs were not a reflection of increased cancer aneuploidy. In a control cohort of 30 patients with pre- and post-chemotherapy matched samples which underwent genomic profiling, no acquired mutations in STK11, KEAP1, SMARCA4, or B2M were detected. Conclusions: Mechanisms of acquired resistance to PD-(L)1 blockade are heterogenous, and new therapeutic strategies are required to delay and overcome ICI resistance in patients with NSCLC.

Diminished Efficacy of Programmed Death-(Ligand)1 Inhibition in STK11- and KEAP1-Mutant Lung Adenocarcinoma Is Affected by KRAS Mutation Status

INTRODUCTION

STK11 and KEAP1 mutations (STK11 mutant [STK11MUT] and KEAP1MUT) are among the most often mutated genes in lung adenocarcinoma (LUAD). Although STK11MUT has been associated with resistance to programmed death-(ligand)1 (PD-[L]1) inhibition in KRASMUT LUAD, its impact on immunotherapy efficacy in KRAS wild-type (KRASWT) LUAD is currently unknown. Whether KEAP1MUT differentially affects outcomes to PD-(L)1 inhibition in KRASMUT and KRASWT LUAD is also unknown.

METHODS

Clinicopathologic and genomic data were collected from September 2013 to September 2020 from patients with advanced LUAD at the Dana-Farber Cancer Institute/Massachusetts General Hospital cohort and the Memorial Sloan Kettering Cancer Center/MD Anderson Cancer Center cohort. Clinical outcomes to PD-(L)1 inhibition were analyzed according to KRAS, STK11, and KEAP1 mutation status in two independent cohorts. The Cancer Genome Atlas transcriptomic data were interrogated to identify differences in tumor gene expression and tumor immune cell subsets, respectively, according to KRAS/STK11 and KRAS/KEAP1 comutation status.

RESULTS

In the combined cohort (Dana-Farber Cancer Institute/Massachusetts General Hospital + Memorial Sloan Kettering Cancer Center/MD Anderson Cancer Center) of 1261 patients (median age = 61 y [range: 22-92], 708 women [56.1%], 1065 smokers [84.4%]), KRAS mutations were detected in 536 cases (42.5%), and deleterious STK11 and KEAP1 mutations were found in 20.6% (260 of 1261) and 19.2% (231 of 1202) of assessable cases, respectively. In each independent cohort and in the combined cohort, STK11 and KEAP1 mutations were associated with significantly worse progression-free (STK11 hazard ratio [HR] = 2.04, p < 0.0001; KEAP1 HR = 2.05, p < 0.0001) and overall (STK11 HR = 2.09, p < 0.0001; KEAP1 HR = 2.24, p < 0.0001) survival to immunotherapy uniquely among KRASMUT but not KRASWT LUADs. Gene expression ontology and immune cell enrichment analyses revealed that the presence of STK11 or KEAP1 mutations results in distinct immunophenotypes in KRASMUT, but not in KRASWT, lung cancers.

CONCLUSIONS

STK11 and KEAP1 mutations confer worse outcomes to immunotherapy among patients with KRASMUT but not among KRASWT LUAD. Tumors harboring concurrent KRAS/STK11 and KRAS/KEAP1 mutations display distinct immune profiles in terms of gene expression and immune cell infiltration.

Prognostic effect of body mass index in patients with advanced NSCLC treated with chemoimmunotherapy combinations

Introduction

It has been recognized that increasing body mass index (BMI) is associated with improved outcome from immune checkpoint inhibitors (ICIs) in patients with various malignancies including non-small cell lung cancer (NSCLC). However, it is unclear whether baseline BMI may influence outcomes from first-line chemoimmunotherapy combinations.

Methods

In this international multicenter study, we evaluated the association between baseline BMI, progression-free survival (PFS) and overall survival (OS) in a cohort of patients with stage IV NSCLC consecutively treated with first-line chemoimmunotherapy combinations. BMI was categorized according to WHO criteria.

Results

Among the 853 included patients, 5.3% were underweight; 46.4% were of normal weight; 33.8% were overweight; and 14.5% were obese. Overweight and obese patients were more likely aged ≥70 years (p=0.00085), never smokers (p<0.0001), with better baseline Eastern Cooperative Oncology Group—Performance Status (p=0.0127), and had lower prevalence of central nervous system (p=0.0002) and liver metastases (p=0.0395). Univariable analyses showed a significant difference in the median OS across underweight (15.5 months), normal weight (14.6 months), overweight (20.9 months), and obese (16.8 months) patients (log-rank: p=0.045, log rank test for trend: p=0.131), while no difference was found with respect to the median PFS (log-rank for trend: p=0.510). Neither OS nor PFS was significantly associated with baseline BMI on multivariable analysis.

Conclusions

In contrast to what was observed in the context of chemotherapy-free ICI-based regimens, baseline BMI does not affect clinical outcomes from chemoimmunotherapy combinations in patients with advanced NSCLC.

Low peripheral blood derived neutrophil-to-lymphocyte ratio (dNLR) is associated with increased tumor T-cell infiltration and favorable outcomes to first-line pembrolizumab in non-small cell lung cancer

BACKGROUND

An elevated peripheral blood derived neutrophil-to-lymphocyte ratio (dNLR) is a negative prognostic marker for patients with non-small cell lung cancer (NSCLC) receiving chemotherapy and immune checkpoint inhibitors. Whether dNLR is also associated with clinical outcomes to first-line pembrolizumab among patients with NSCLC and a programmed cell death ligand 1 (PD-L1) Tumor Proportion Score (TPS) of ≥50% is uncertain. How dNLR relates to the tumor immune microenvironment is also unclear.

METHODS

In two participating academic centers, we retrospectively analyzed the dNLR (defined as the absolute neutrophil count/white cell count - absolute neutrophil count) prior to initiation of first-line pembrolizumab in patients with metastatic NSCLC and a PD-L1 TPS ≥50% and lacking genomic alterations in EGFR and ALK. An unbiased recursive partitioning algorithm was used to investigate an optimal dNLR cut-off with respect to objective response rate (ORR). Multiplexed immunofluorescence for CD8+, FOXP3+, PD-1+, and PD-L1 was performed on a separate cohort of NSCLCs to determine the immunophenotype associated with dNLR.

RESULTS

A total of 221 patients treated with first-line pembrolizumab were included in this study. The optimal dNLR cut-off to differentiate treatment responders from non-responders was 2.6. Compared with patients with a dNLR ≥2.6 (n=97), patients with dNLR <2.6 (n=124) had a significantly higher ORR (52.4% vs 24.7%, p<0.001), a significantly longer median progression-free survival (mPFS 10.4 vs 3.4 months, HR 0.48, 95% CI 0.35 to 0.66, p<0.001), and a significantly longer median overall survival (mOS 36.6 vs 9.8 months, HR 0.34, 95% CI 0.23 to 0.49, p<0.001). After adjusting for age, sex, tobacco use, performance status, histology, serum albumin level, oncogenic driver status, and PD-L1 distribution (50%-89% vs ≥90%), a dNLR <2.6 was confirmed to be an independent predictor of longer mPFS (HR 0.47, 95% CI 0.33 to 0.67, p<0.001) and mOS (HR 0.32, 95% CI 0.21 to 0.49, p<0.001). Among advanced NSCLC samples with a PD-L1 TPS of ≥50%, those with a dNLR <2.6 had significantly higher numbers of tumor-associated CD8+, FOXP3+, PD-1 +immune cells, and PD-1 +CD8+T cells than those with a dNLR ≥2.6.

CONCLUSIONS

Among patients with NSCLC and a PD-L1 TPS ≥50%, a low dNLR has a distinct immune tumor microenvironment and more favorable outcomes to first-line pembrolizumab.

Antibiotic-exposed patients with non-small-cell lung cancer preserve efficacy outcomes following first-line chemo-immunotherapy

BACKGROUND

Prior antibiotic therapy (pATB) is known to impair efficacy of single-agent immune checkpoint inhibitors (ICIs), potentially through the induction of gut dysbiosis. Whether ATB also affects outcomes to chemo-immunotherapy combinations is still unknown.

PATIENTS AND METHODS

In this international multicentre study, we evaluated the association between pATB, concurrent ATB (cATB) and overall survival (OS), progression-free survival (PFS) and objective response rate (ORR) in patients with non-small-cell lung cancer (NSCLC) treated with first-line chemo-immunotherapy at eight referral institutions.

RESULTS

Among 302 patients with stage IV NSCLC, 216 (71.5%) and 61 (20.2%) patients were former and current smokers, respectively. Programmed death-ligand 1 tumour expression in assessable patients (274, 90.7%) was ≥50% in 76 (25.2%), 1%-49% in 84 (27.9%) and <1% in 113 (37.5%). Multivariable analysis showed pATB-exposed patients to have similar OS {hazard ratio (HR) = 1.42 [95% confidence interval (CI): 0.91-2.22]; P = 0.1207} and PFS [HR = 1.12 (95% CI: 0.76-1.63); P = 0.5552], compared to unexposed patients, regardless of performance status. Similarly, no difference with respect to ORR was found across pATB exposure groups (42.6% versus 57.4%, P = 0.1794). No differential effect was found depending on pATB exposure duration (≥7 versus <7 days) and route of administration (intravenous versus oral). Similarly, cATB was not associated with OS [HR = 1.29 (95% CI: 0.91-1.84); P = 0.149] and PFS [HR = 1.20 (95% CI: 0.89-1.63); P = 0.222] when evaluated as time-varying covariate in multivariable analysis.

CONCLUSIONS

In contrast to what has been reported in patients receiving single-agent ICIs, pATB does not impair clinical outcomes to first-line chemo-immunotherapy of patients with NSCLC. pATB status should integrate currently available clinico-pathologic factors for guiding first-line treatment decisions, whilst there should be no concern in offering cATB during chemo-immunotherapy when needed.