Overall survival in patients with advanced non-small cell lung cancer with KRAS G12C mutation with or without STK11 and/or KEAP1 mutations in a real-world setting

Differential Response and Resistance to KRAS-Targeted Therapy

KRAS is the most frequently mutated oncogene. In epithelial malignancies such as lung, colorectal, and pancreatic tumors, KRAS is mutated in 25 to above 90% cases. KRAS was considered undruggable for over three decades until the recent development of covalent inhibitors targeting the KRAS G12C mutant. The recent approval of the KRAS G12C inhibitors sotorasib and adagrasib has ushered in a new era of KRAS-targeted therapy. Despite this success, a major challenge in KRAS-targeted therapy is intrinsic and acquired resistance to KRAS inhibitors. Clinical studies have shown that many patients with KRAS G12C cancers did not respond to sotorasib and adagrasib. Colorectal cancer, in particular, has a markedly lower response rate to KRAS G12C inhibitors compared to non-small cell lung cancer. Furthermore, the therapeutic response to KRAS G12C inhibition was short-lived, with quick emergence of acquired resistance. In this review, we summarize several major themes that have emerged from recent clinical and preclinical studies on the mechanisms of intrinsic and acquired resistance to KRAS-targeted therapy in colorectal, lung, and pancreatic cancers. We also discuss various combination strategies for targeting these mechanisms to overcome resistance to KRAS inhibitors.

Real-World outcomes of Non-Small cell lung cancer patients harbouring KRAS G12C and KRAS G12D mutations

BACKGROUND

KRAS G12D and G12C mutations have distinct biological traits influencing treatment response. This study examines real-world demographics, clinical characteristics, and first-line treatment outcomes in metastatic non-small-cell lung cancer (NSCLC) patients with these mutations.

METHODS

This retrospective, multi-institution observational study used data from the AURORA database. Patients aged 18 years or older, diagnosed with metastatic KRAS G12D or G12C NSCLC between January 1, 2010, and April 30, 2024, were included. Descriptive statistics compared patient characteristics, and time-to-event outcomes were assessed using Cox proportional hazards regression.

RESULTS

A total of 298 (216 KRAS G12C and 82 KRAS G12D) patients were included. The KRAS G12D group had a higher proportion of never smokers (15 % vs. 1 %, p < 0.01) and PD-L1 < 1 % (36 % vs. 21 %, p = 0.06). No significant differences were observed in overall survival (OS) (HR 1.09, 95 % CI 0.80-1.48, p = 0.60) or real-world progression-free survival (rwPFS) (HR 1.21, 95 % CI 0.92-1.59, p = 0.18) between mutation groups. In KRAS G12C, monotherapy immunotherapy (HR 0.61, 95 % CI 0.39-0.97, p = 0.04) and chemo-immunotherapy (HR 0.59, 95 % CI 0.37-0.94, p = 0.03) improved OS compared to chemotherapy. For KRAS G12D, neither immunotherapy (HR 0.74, 95 % CI 0.29-1.89, p = 0.53) nor chemo-immunotherapy (HR 0.73, 95 % CI 0.34-1.57, p = 0.42) improved OS compared to chemotherapy alone.

CONCLUSION

KRAS G12C and G12D mutations demonstrate distinct clinical characteristics and treatment responses, with poorer immunotherapy outcomes in KRAS G12D patients. Prospective studies are needed to validate these findings.

Intracranial Disease Control and Survival among Patients with KRAS-mutant Lung Adenocarcinoma and Brain Metastases Treated with Stereotactic Radiosurgery

PURPOSE

Precision medicine according to molecularly defined subgroups offers great potential to improve outcomes for patients with metastatic lung adenocarcinoma. This study describes clinical outcomes and the impact of co-occurring genetic alterations on outcomes following stereotactic radiosurgery (SRS) among patients with Kirsten rat sarcoma viral oncogene homolog (KRAS)-mutant lung adenocarcinoma.

METHODS AND MATERIALS

A total of 195 patients with KRAS-mutant lung adenocarcinoma were treated with SRS for brain metastases (BMs) between 2014 and 2018 with follow-up until 2022 or death. Coprimary outcomes were median overall survival (OS) and intracranial progression-free survival (iPFS); univariable and multivariable Cox regression models and Kaplan-Meier survival analysis were used.

RESULTS

Median follow-up from the date of BM diagnosis was 11 months. Median OS and iPFS for the cohort were 27.7 months (95% CI, 19.7-36.8) and 22.1 months (95% CI, 16.8-48.9), respectively. Lesion-level local control at 12 and 24 months was 89.9% and 87.5%, respectively. In a multivariable Cox regression model, inferior OS was associated with coalterations in KEAP1 and STK11 (hazard ratio [HR], 1.94; 95% CI, 1.04-3.62; q = 0.087), progressive (HR, 3.41; 95% CI, 1.38-8.39; q = 0.087), and mixed response (HR, 3.52; 95% CI, 1.2-10.3; q = 0.092) extracranial disease, and 6 or more BMs at time of diagnosis (HR, 2.58; 95% CI, 1.22-6.63; q = 0.087). Positive programmed death ligand 1 status was associated with improved OS (HR, 0.57; 95% CI, 0.37-0.87; P = .01). Inferior iPFS was associated with chemotherapy before SRS (HR, 2.69; 95% CI, 1.42-5.09; q = 0.04) and age >65 years (HR, 2.21; 95% CI, 1.25-3.93; q = 0.055). KRAS G12C was not associated with differences in iPFS, OS, or type of intracranial progression event following SRS.

CONCLUSIONS

Coalteration of KRAS and KEAP1/STK11 was associated with inferior OS, but not iPFS. Similar outcomes were found in patients harboring KRAS G12C and non-G12C mutant non-small cell lung cancer BMs. Further understanding of molecularly characterized subgroups will be critical in driving personalized radiation therapy for patients with lung cancer BMs.

Durvalumab With or Without Tremelimumab in Combination With Chemotherapy in First-Line Metastatic NSCLC: Five-Year Overall Survival Outcomes From the Phase 3 POSEIDON Trial

INTRODUCTION

The primary analysis (median follow-up 34.9 mo across all arms) of the phase 3 POSEIDON study revealed a statistically significant overall survival (OS) improvement with first-line tremelimumab plus durvalumab and chemotherapy (T+D+CT) versus CT in patients with EGFR and ALK wild-type metastatic NSCLC (mNSCLC). D+CT had a trend for OS improvement versus CT that did not reach statistical significance. This article reports prespecified OS analyses after long-term follow-up (median >5 y).

METHODS

A total of 1013 patients were randomized (1:1:1) to T+D+CT, D+CT, or CT, stratified by tumor cell programmed cell death ligand-1 (PD-L1) expression (≥50% versus <50%), disease stage (IVA versus IVB), and tumor histologic type (squamous versus nonsquamous). Serious adverse events were collected during follow-up.

RESULTS

After a median follow-up of 63.4 months across all arms, T+D+CT had sustained OS benefit versus CT (hazard ratio [HR] = 0.76, 95% confidence interval [CI]: 0.64-0.89; 5-y OS: 15.7% versus 6.8%). OS improvement with D+CT versus CT (HR = 0.84, 95% CI: 0.72-1.00; 5-y OS: 13.0%) was consistent with the primary analysis. OS benefit with T+D+CT versus CT remained more pronounced in nonsquamous (HR = 0.69, 95% CI: 0.56-0.85) versus squamous (HR = 0.85, 95% CI: 0.65-1.10) mNSCLC. OS benefit with T+D+CT versus CT was still evident regardless of PD-L1 expression, including patients with PD-L1 tumor cell less than 1%, and remained evident in STK11-mutant (nonsquamous), KEAP1-mutant, and KRAS-mutant (nonsquamous) mNSCLC. No new safety signals were identified.

CONCLUSIONS

After a median follow-up of more than 5 years, T+D+CT had durable long-term OS benefit versus CT, supporting its use as first-line treatment in mNSCLC, including in patient subgroups with harder-to-treat disease.

Emerging insights into STK11, KEAP1 and KRAS mutations: implications for immunotherapy in patients with advanced non-small cell lung cancer

Immune checkpoint inhibitors (ICIs) have become an established treatment option for patients with advanced non-small cell lung cancer (NSCLC). However, the efficacy of single-agent immunotherapy as well as in combination with chemotherapy seems to be dependent on the presence of molecular abnormalities in some genes-serine/threonine kinase 11 (STK11), Kelch-like ECH-associated protein 1 (KEAP1) and Kirsten rat sarcoma viral oncogene homolog (KRAS) among them. The KEAP1 gene is a critical regulator of the cellular response to oxidative stress and electrophilic stress, thus playing a pivotal role in maintaining cellular homeostasis. The STK11 gene encodes a serine/threonine kinase (STK11) involved the regulation of cell growth, polarity, motility, differentiation and cell metabolism. The STK11 gene mutations are often associated with an immunologically "cold" tumour microenvironment. The co-occurrence of STK11 or KEAP1 abnormalities with the KRAS mutation changes the composition of the tumour microenvironment as compared when presented alone. The current data, based on retrospective analyses of clinical trials, indicate that the co-existence of STK11 and KEAP1 genes mutations with the KRAS gene mutations have negative impact on the prognosis, regardless of treatment methods, in patients with advanced NSCLC. However, this group of patients should not be omitted because they constitute a significant percentage of advanced NSCLC patients. Immunotherapy focused on two ICIs [anti-programmed death 1 (PD-1)/anti-cytotoxic T-lymphocyte antigen 4 (CTLA-4)] combined with chemotherapy, may be more effective than immunotherapy or chemotherapy alone in this group of patients. Confirmation of this thesis can be found in the results of available clinical studies. Here, we summarize the theoretical justification as well as the results of clinical trials for combining immunotherapy in patients with STK11-, KEAP1- and KRAS-mutated genes. There is certainly a need to create a prospective clinical trial to assess the effectiveness of combined immunotherapy in the discussed group of patients.

Clinical perspectives on the value of testing for STK11 and KEAP1 mutations in advanced NSCLC

Standard first-line therapy for patients with metastatic non-small cell lung cancer (mNSCLC) without identified actionable mutations consists of regimens comprising immune checkpoint inhibitors (ICIs), alone or in combination with platinum-based chemotherapy (CTx). However, approximately 20-30% of patients with mNSCLC (including some patients with high tumor programmed cell death ligand-1 expression) display primary resistance to ICIs, either alone or in combination with CTx. Mutations in tumor suppressor genes serine/threonine kinase 11 (STK11), and Kelch-like ECH-associated protein 1 (KEAP1) often detected in patients with Kirsten rat sarcoma virus mutations, are associated with an aggressive disease phenotype and resistance to standard ICI regimens. Consequently, there is an important need for effective treatments for patients with NSCLC with STK11 or KEAP1 mutations. In this article, we describe new data on the prevalence of STK11 and KEAP1 mutations in a large clinical population, consider practicalities around the detection of these mutations using available biomarker testing methodologies, and describe experiences of managing some of these difficult-to-treat patients in our clinical practice.

Integrated proteomic and glycoproteomic analysis reveals heterogeneity and molecular signatures of brain metastases from lung adenocarcinomas

Brain metastasis is a major cause of poor prognosis and death in lung adenocarcinoma (LUAD); however, the understanding of therapeutic strategies and mechanisms for brain metastases from LUAD (BM-LUAD) remains notably limited, especially at the proteomics levels. To address this issue, we conducted integrated proteomic and glycoproteomic analyses on 49 BM-LUAD tumors, revealing two distinct subtypes of the disease: BM-S1 and BM-S2. Whole exome sequencing analysis revealed that somatic mutations in STK11 and KEAP1, as well as copy number deletions on chr19p13.3, such as STK11, UQCR11, and SLC25A23, were more frequently detected in BM-S2. In BM-S1 tumors, we observed significant infiltration of GFAP + astrocytes, as evidenced by elevated levels of GFAP, GABRA2, GABRG1 and GAP43 proteins and an enrichment of astrocytic signatures in both our proteomic data and external spatial transcriptomic data. Conversely, BM-S2 tumors demonstrated higher levels of PD-1 immune cell infiltration, supported by the upregulation of PD-1 and LAG-3 genes. These findings suggest distinct microenvironmental adaptations required by the different BM-LUAD subtypes. Additionally, we observed unique glycosylation patterns between the subtypes, with increased fucosylation in BM-S1 and enhanced sialylation in BM-S2, primarily affected by glycosylation enzymes such as FUT9, B4GALT1, and ST6GAL1. Specifically, in BM-S2, these sialylation modifications are predominantly localized to the lysosomes, underscoring the critical role of N-glycosylation in the tumor progression of BM-LUAD. Overall, our study not only provides a comprehensive multi-omic data resource but also offers valuable biological insights into BM-LUAD, highlighting potential mechanisms and therapeutic targets for further investigation.

Treatment patterns and outcomes in KRASG12C-positive advanced NSCLC patients previously treated with immune checkpoint inhibitors: A Canada-wide real-world, multi-center, retrospective cohort study

OBJECTIVES

KRAS mutations, particularly KRASG12C, are prevalent in non-small cell lung cancer (NSCLC). Immune checkpoint inhibitors (ICIs) have been a frontline treatment, but recently developed KRASG12C-selective inhibitors, such as sotorasib, present new therapeutic options. We conducted a multi-center retrospective cohort study to gain insights into real-world treatment patterns and outcomes in patients with KRASG12C-positive advanced NSCLC receiving systemic therapy post-ICI treatment.

METHODS

From the CAnadian CAncers With Rare Molecular Alterations-Basket Real-world Observational Study (CARMA-BROS), a cohort of 102 patients with KRASG12C-positive advanced NSCLC across 9 Canadian centers diagnosed between 2015 and 2021 was analyzed. Clinico-demographic and treatment data were obtained from electronic health records. Survival outcomes were assessed using Kaplan-Meier curves and Cox proportional hazards models.

RESULTS

The patients (median age 66 years; 58 % female; 99 % current/former tobacco exposure; 59 % PD-L1 ≥ 50 %), exhibited heterogeneous treatment patterns post-ICI. Most patients received ICIs as a first-line therapy, with varying subsequent lines including chemotherapy and targeted therapy. In patients receiving systemic therapy post-ICI, median overall survival was 12.6 months, and real-world progression-free survival was 4.7 months. KRASG12C-selective targeted therapy post-ICI (n = 20) showed longer real-world progression-free survival compared to single-agent chemotherapy (aHR = 0.39, p = 0.012).

CONCLUSION

This study contributes valuable real-world data on KRASG12C-positive advanced NSCLC post-ICI treatment. The absence of a standard treatment sequencing post-ICI underscores the need for further investigation and consensus-building in the evolving landscape of KRASG12C-targeted therapies.

Orthotopic Models Using New, Murine Lung Adenocarcinoma Cell Lines Simulate Human Non-Small Cell Lung Cancer Treated with Immunotherapy

Understanding tumor-host immune interactions and the mechanisms of lung cancer response to immunotherapy is crucial. Current preclinical models used to study this often fall short of capturing the complexities of human lung cancer and lead to inconclusive results. To bridge the gap, we introduce two new murine monoclonal lung cancer cell lines for use in immunocompetent orthotopic models. We demonstrate how our cell lines exhibit immunohistochemical protein expression (TTF-1, NapA, PD-L1) and common driver mutations (KRAS, p53, and p110α) seen in human lung adenocarcinoma patients, and how our orthotopic models respond to combination immunotherapy in vivo in a way that closely mirrors current clinical outcomes. These new lung adenocarcinoma cell lines provide an invaluable, clinically relevant platform for investigating the intricate dynamics between tumor and the immune system, and thus potentially contributes to a deeper understanding of immunotherapeutic approaches to lung cancer treatment.

Clinical Management of Patients with Non-Small Cell Lung Cancer, Brain Metastases, and Actionable Genomic Alterations: A Systematic Literature Review

INTRODUCTION

Nearly 60% of patients with non-small cell lung cancer (NSCLC) present with metastatic disease, and approximately 20% have brain metastases (BrMs) at diagnosis. During the disease course, 25-50% of patients will develop BrMs. Despite available treatments, survival rates for patients with NSCLC and BrMs remain low, and their overall prognosis is poor. Even with newer agents for NSCLC, options for treating BrMs can be limited by their ineffective transport across the blood-brain barrier (BBB) and the unique brain tumor microenvironment. The presence of actionable genomic alterations (AGAs) is a key determinant of optimal treatment selection, which aims to maximize responses and minimize toxicities. The objective of this systematic literature review (SLR) was to understand the current landscape of the clinical management of patients with NSCLC and BrMs, particularly those with AGAs.

METHOD

A Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA)-compliant SLR was conducted to identify studies in patients with BrMs in NSCLC. Searches used the EMBASE and MEDLINE® databases, and articles published between January 1, 2017 and September 26, 2022 were reviewed.

RESULTS

Overall, 179 studies were included in the SLR. This subset review focused on 80 studies that included patients with NSCLC, BrMs, and AGAs (19 randomized controlled trials [RCTs], two single-arm studies, and 59 observational studies). Sixty-four of the 80 studies reported on epidermal growth factor receptor (EGFR) mutations, 14 on anaplastic lymphoma kinase (ALK) alterations, and two on both alterations. Ninety-five percent of studies evaluated targeted therapy. All RCTs allowed patients with previously treated, asymptomatic, or neurologically stable BrMs; the percentage of asymptomatic BrMs varied across observational studies.

CONCLUSIONS

Although targeted therapies demonstrate systemic benefits for patients with NSCLC, BrMs, and AGAs, there remains a continued need for effective therapies to treat and prevent BrMs in this population. Increased BBB permeability of emerging therapies may improve outcomes for this population.

Prognostic implications of STK11 with different mutation status and its relationship with tumor-infiltrating immune cells in non-small cell lung cancer

Background

Mutations in STK11 (STK11Mut) gene may present a negative impact on survival in Non-small Cell Lung Cancer (NSCLC) patients, however, its relationship with immune related genes remains unclear. This study is to unveil whether overexpressed- and mutated-STK11 impact survival in NSCLC and to explore whether immune related genes (IRGs) are involved in STK11 mutations.

Methods

188 NSCLC patients with intact formalin-fixed paraffin-embedded (FFPE) tissue available for detecting STK11 protein expression were included in the analysis. After immunohistochemical detection of STK11 protein, patients were divided into high STK11 expression group (STK11High) and low STK11 expression group (STK11Low), and then Kaplan-Meier survival analysis and COX proportional hazards model were used to compare the overall survival (OS) and progression-free survival (PFS) of the two groups of patients. In addition, the mutation data from the TCGA database was used to categorize the NSCLC population, namely STK11 Mutated (STK11Mut) and wild-type (STK11Wt) subgroups. The difference in OS between STK11Mut and STK11Wt was compared. Finally, bioinformatics analysis was used to compare the differences in IRGs expression between STK11Mut and STK11Wt populations.

Results

The median follow-up time was 51.0 months (range 3.0 - 120.0 months) for real-life cohort. At the end of follow-up, 64.36% (121/188) of patients experienced recurrence or metastasis. 64.89% (122/188) of patients ended up in cancer-related death. High expression of STK11 was a significant protective factor for NSCLC patients, both in terms of PFS [HR=0.42, 95% CI= (0.29-0.61), P<0.001] and OS [HR=0.36, 95% CI= (0.25, 0.53), P<0.001], which was consistent with the finding in TCGA cohorts [HR=0.76, 95%CI= (0.65, 0.88), P<0.001 HR=0.76, 95%CI= (0.65, 0.88), P<0.001]. In TCGA cohort, STK11 mutation was a significant risk factor for NSCLC in both lung squamous cell carcinoma (LUSC) and lung adenocarcinoma (LUAD) histology in terms of OS [HR=6.81, 95%CI= (2.16, 21.53), P<0.001; HR=1.50, 95%CI= (1.00, 2.26), P=0.051, respectively]. Furthermore, 7 IRGs, namely CALCA, BMP6, S100P, THPO, CGA, PCSK1 and MUC5AC, were found significantly overexpressed in STK11-mutated NSCLC in both LUSC and LUAD histology.

Conclusions

Low STK11 expression at protein level and presence of STK11 mutation were associated with poor prognosis in NSCLC, and mutated STK11 might probably alter the expression IRGs profiling.