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.

Effect of STK11 mutations on efficacy of PD-1 inhibition in non-small cell lung cancer (NSCLC) and dependence on KRAS mutation status

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Background: STK11 mutations ( STK11m) have been associated with resistance to ICI in KRAS-mutant ( KRASm) NSCLC. Whether STK11m status also impacts clinical outcomes to ICI in KRAS wild-type (wt) NSCLC is unknown. Methods: We analyzed clinical outcomes of patients (pts) with NSCLC treated with ICI according to KRAS and STK11 mutation status in independent discovery (DFCI+MGH) and validation (MSKCC) cohorts. TCGA and xCell data were interrogated to identify differences in tumor gene expression and tumor immune cell subsets, respectively, according to KRAS/ STK11 co-mutation status. Results: Of 1195 pts with advanced nonsquamous NSCLC treated with ICI, 447 (37.4%) had a KRASm, 252 (21.1%) had pathogenic STK11 mutations, and 128 (10.7%) had concurrent KRASm and STK11m. ICI outcomes for the discovery and validation cohorts in KRASm and KRASwt cases by STK11 mutation status are shown in Table. In the combined cohort (discovery+validation), STK11m was associated with significantly worse outcomes to ICI among KRASm cases: ORR 10.2% vs 30.7%, P < 0.001; median progression-free survival (mPFS): 2.0 vs 4.8 months (mo), HR:0.49 [95%CI:0.39-0.61], P < 0.0001; median overall survival (mOS): 6.1 vs 16.9 mo, HR:0.50 [95%CI:0.39-0.63], P < 0.0001. In multivariable analysis, STK11m was associated with significantly shorter PFS (HR:0.56, P = 0.002) and OS (HR:0.57, P = 0.006). By contrast, STK11m had no impact on ICI outcomes among KRASwt cases: ORR 24.2% vs 19.2%, P = 0.21; mPFS: 2.5 vs 2.8 mo, HR:0.98 [95%CI:0.79-1.21], P = 0.89; mOS: 12.0 vs 11.5 mo, HR:1.06 [95%CI:0.85-1.33], P = 0.57. Among KRASwt cases, STK11m had no impact on ICI outcomes among both smokers and never smokers, when analyzed separately. Gene ontology analysis from TCGA revealed that among KRASm but not KRASwt NSCLC, STK11m was associated with the downregulation of MHC class II-related genes (P = 0.02). Cell subset transcriptome analysis showed significantly lower proportions of M1 macrophages among KRASm/ STK11m but not among KRASwt/ STK11m NSCLCs (P < 0.01). Conclusions: STK11m are associated with resistance to ICI in KRASm but not KRASwt NSCLC. STK11m/ KRASm vs STK11m/ KRASwt NSCLC have distinct immunophenotypes. [Table: see text]

Clinical activity of programmed cell death 1 (PD-1) blockade in never, light, and heavy smokers with non-small-cell lung cancer and PD-L1 expression ≥50

Background:

Immune checkpoint inhibitors (ICIs) are standard therapies for patients with advanced non-small-cell lung cancer (NSCLC) and a programmed death-ligand 1 (PD-L1) tumor proportion score (TPS) ≥50%. Tumor mutation burden (TMB) also predicts response to ICIs but is often not available in real time for decision making in the first-line setting. Smoking exposure can be a proxy for TMB in NSCLC. The impact of smoking status on efficacy of PD-1 blockade in NSCLC patients with PD-L1 TPS ≥50% has not been well defined.

Patients and methods:

To investigate the relationship between smoking and activity of ICIs in NSCLC, we retrospectively studied 315 patients with NSCLC and PD-L1 TPS ≥50% at five USA academic medical centers. Objective response rates (ORRs), progression-free survival (PFS), and duration of response (DOR) were compared between never (<100 lifetime cigarettes), light (≤10 pack-years), and heavy (>10 pack-years) smokers. A subset of patients underwent next-generation sequencing to estimate TMB.

Results:

We identified 36 (11%) never, 42 (13%) light, and 237 (75%) heavy smokers with NSCLC and PD-L1 TPS ≥50% treated with ICIs. Objective responses were observed in 27%, 40%, and 40% of never, light, and heavy smokers, respectively (P = 0.180 never versus heavy; P = 1.000 light versus heavy). Median PFS and median DOR were numerically shorter in never and light smokers compared with heavy smokers (PFS 3.0 versus 4.0 versus 5.4 months; median DOR 6.9 versus 10.8 versus 17.8 months), but were not statistically different [PFS: hazard ratio (HR) 1.37, P = 0.135 and HR 1.24, P = 0.272; DOR: HR 1.92, P = 0.217 and HR 1.79, P = 0.141].

Conclusions:

PD-(L)1 inhibitors are associated with antitumor activity in NSCLC with PD-L1 TPS ≥50% regardless of smoking status. Nevertheless, there is a signal of potentially decreased durability among never and light smokers that should be further evaluated. Distinct immunobiologic features may affect initial response versus durability of antitumor immunity to programmed cell death 1 (PD-1) blockade.

Outcomes to first-line pembrolizumab in patients with non-small-cell lung cancer and very high PD-L1 expression

BACKGROUND

In non-small-cell lung cancers with programmed death-ligand 1 (PD-L1) expression on ≥50% of tumor cells, first-line treatment with the PD-1 inhibitor pembrolizumab improves survival compared with platinum-doublet chemotherapy. Whether higher PD-L1 levels within the expression range of 50%-100% predict for even greater benefit to pembrolizumab is currently unknown.

PATIENTS AND METHODS

In this multicenter retrospective analysis, we analyzed the impact of PD-L1 expression levels on the overall response rate (ORR), median progression-free survival (mPFS), and median overall survival (mOS) in patients who received commercial pembrolizumab as first-line treatment of non-small-cell lung cancer (NSCLC) with a PD-L1 expression of ≥50% and negative for genomic alterations in the EGFR and ALK genes .

RESULTS

Among 187 patients included in this analysis, the ORR was 44.4% [95% confidence interval (CI) 37.1% to 51.8%], the mPFS was 6.5 months (95% CI 4.5-8.5), and the mOS was not reached. The median PD-L1 expression level among patients who experienced a response to pembrolizumab was significantly higher than among patients with stable or progressive disease (90% versus 75%, P < 0.001). Compared with patients with PD-L1 expression of 50%-89% (N = 107), patients with an expression level of 90%-100% (N = 80) had a significantly higher ORR (60.0% versus 32.7%, P < 0.001), a significantly longer mPFS [14.5 versus 4.1 months, hazard ratio (HR) 0.50 (95% CI 0.33-0.74), P < 0.01], and a significantly longer mOS [not reached versus 15.9 months, HR 0.39 (95% CI 0.21-0.70), P = 0.002].

CONCLUSION

Among patients with NSCLC and PD-L1 expression of ≥50% treated with first-line pembrolizumab, clinical outcomes are significantly improved in NSCLCs with a PD-L1 expression of ≥90%. These findings have implications for treatment selection as well as for clinical trial interpretation and design.

Outcomes to first-line pembrolizumab in patients with non-small cell lung cancer and a PD-L1 tumor proportion score ≥90%

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Background: In non-small cell lung cancers with a programmed death-ligand 1 (PD-L1) tumor proportion score (TPS) of ≥50%, first-line treatment with the PD-1 inhibitor pembrolizumab improves survival compared to platinum-doublet chemotherapy. Whether higher PD-L1 expression levels within the TPS range of 50-100% predict for even greater benefit to pembrolizumab is currently unknown. Methods: In this multicenter retrospective analysis, we analyzed the impact of PD-L1 expression levels on the overall response rate (ORR), median progression-free survival (mPFS), and median overall survival (mOS) in patients who received commercial pembrolizumab as first-line treatment for advanced NSCLC with a PD-L1 TPS of ≥50%. Results: Among 196 patients with NSCLC treated with first-line pembrolizumab, the ORR was 43.8% (95%CI: 36.8-51.1). At a median follow-up of 12.6 months (95%CI: 11.6-13.7), the mPFS was 6.2 months (95% CI: 4.2-8.2) and the mOS was not reached. The median PD-L1 TPS among patients who experienced a response to pembrolizumab was significantly higher than in patients with stable or progressive disease (TPS 90% vs 70%, P < 0.001), so a TPS cut point of 90% was chosen for further analysis. Baseline clinicopathological characteristics were well-balanced between patients with a PD-L1 TPS of 50-89% vs 90-100%. Compared to patients with a PD-L1 TPS of 50-89% (N = 114, 58.2% of the cohort), patients with a TPS of 90-100% (N = 82, 41.8% of the cohort) had a significantly higher ORR (61.0% versus 31.6%, P < 0.001), a significantly longer mPFS (13.2 versus 3.7 months, HR: 0.48 [95% CI: 0.33-0.71], P < 0.001), and a significantly longer mOS (NR versus 16.0 months, HR: 0.38 [95% CI: 0.21-0.70], P = 0.002). After adjusting for ECOG performance status and smoking history, PD-L1 TPS of 90-100% was significantly associated with improved mPFS (HR: 0.51 [95% CI: 0.34-0.75], P < 0.001) and mOS (HR: 0.38 [95% CI: 0.21-0.70], P = 0.001). Conclusions: Among patients with NSCLC and a PD-L1 TPS ≥50%, clinical outcomes are improved in the subgroup of patients with a PD-L1 TPS of ≥90%. These findings have implications for treatment selection as well as for clinical trial interpretation and design.