A single institution study evaluating outcomes of PD-L1 high KRAS-mutant advanced non-small cell lung cancer (NSCLC) patients treated with first line immune checkpoint inhibitors

Prognostic Value of KRAS Mutations in Relation to PDL1 Expression and Immunotherapy Treatment in Adenocarcinoma and Squamous Cell Carcinoma Patients: A Greek Cohort Study

BACKGROUND

Factors that could predict which patients will benefit from Immune Checkpoint Inhibitors (ICIs) are not fully understood. This study aimed to investigate the prognostic value of KRAS biomarker in patients with advanced non-small cell lung cancer (NSCLC) in relation to clinical characteristics, treatment response and PDL1 expression.

PATIENTS AND METHODS

The study included 100 patients with NSCLC who received immunotherapy with or without chemotherapy as 1st line treatment. In biopsy samples, the PDL1 biomarker expression rate and somatic mutations of KRAS gene were determined.

RESULTS

The mean age of the patients was 67 ± 8 years. Patients were all male and 66% were found with adenocarcinoma whereas 34% with squamous cell carcinoma. The KRAS G12C mutation was found with the highest percentage (73%). In the Kaplan-Meier survival analysis, patients with PDL1 > 49% in combination with a negative KRAS result had a median overall survival of 40 months compared to patients with a positive KRAS result (9 months, p < 0.05). In addition, patients diagnosed with adenocarcinoma, PDL1 < 49% and negative KRAS result had a median overall survival of 39 months compared to patients with a positive result (28 months, p < 0.05).

CONCLUSIONS

Our study suggests that the presence of KRAS mutations in advanced NSCLC patients has a poor prognostic value, regardless of their PDL1 expression values, after receiving immunotherapy as first-line treatment.

Progresses in biomarkers for cancer immunotherapy

Currently, checkpoint inhibitor-based immunotherapy has emerged as prevailing treatment modality for diverse cancers. However, immunotherapy as a first-line therapy has not consistently yielded durable responses. Moreover, the risk of immune-related adverse events increases with combination regimens. Thus, the development of predictive biomarkers is needed to optimize individuals benefit, minimize risk of toxicities, and guide combination approaches. The greatest focus has been on tumor programmed cell death-ligand 1 (PD-L1), microsatellite instability (MSI), and tumor mutational burden (TMB). However, there remains a subject of debate due to thresholds variability and significant heterogeneity. Major unmet challenges in immunotherapy are the discovery and validation of predictive biomarkers. Here, we show the status of tumor PD-L1, MSI, TMB, and emerging data on novel biomarker strategies with oncogenic signaling and epigenetic regulation. Considering the exploration of peripheral and intestinal immunity has served as noninvasive alternative in predicting immunotherapy, this review also summarizes current data in systemic immunity, encompassing solute PD-L1 and TMB, circulating tumor DNA and infiltrating lymphocytes, routine emerging inflammatory markers and cytokines, as well as gut microbiota. This review provides up-to-date information on the evolving field of currently available biomarkers in predicting immunotherapy. Future exploration of novel biomarkers is warranted.

Breaking the 'Undruggable' Barrier: Anti-PD-1/PD-L1 Immunotherapy for Non-Small Cell Lung Cancer Patients with KRAS Mutations-A Comprehensive Review and Description of Single Site Experience

Kirsten rat sarcoma viral oncogene homologue (KRAS) gene mutations are among the most commonly found oncogenic alterations in non-small cell lung cancer (NSCLC) patients. Unfortunately, KRAS mutations have been considered "undruggable" for many years, making treatment options very limited. Immunotherapy targeting programmed death-ligand 1 (PD-L1), programmed death 1 (PD-1) and cytotoxic T lymphocyte antigen 4 (CTLA-4) has emerged as a promising therapeutic option for NSCLC patients. However, some studies have suggested a lower response rate to immunotherapy in KRAS-mutated NSCLC patients with the coexistence of mutations in the STK11 (Serine/Threonine Kinase 11) gene. However, recent clinical trials have shown promising results with the combination of immunotherapy and chemotherapy or immunotherapy and KRAS inhibitors (sotorasib, adagrasib) in such patients. In other studies, the high efficacy of immunotherapy has been demonstrated in NSCLC patients with mutations in the KRAS gene that do not coexist with other mutations or coexist with the TP53 gene mutations. In this paper, we review the available literature on the efficacy of immunotherapy in KRAS-mutated NSCLC patients. In addition, we presented single-site experience on the efficacy of immunotherapy in NSCLC patients with KRAS mutations. The effectiveness of chemoimmunotherapy or immunotherapy as well as KRAS inhibitors extends the overall survival of advanced NSCLC patients with the G12C mutation in the KRAS gene to 2-3 years. This type of management has become the new standard in the treatment of NSCLC patients. Further studies are needed to clarify the potential benefits of immunotherapy in KRAS-mutated NSCLC patients and to identify potential biomarkers that may help predict response to therapy.

KRAS Mutations in Solid Tumors: Characteristics, Current Therapeutic Strategy, and Potential Treatment Exploration

Kristen rat sarcoma (KRAS) gene is one of the most common mutated oncogenes in solid tumors. Yet, KRAS inhibitors did not follow suit with the development of targeted therapy, for the structure of KRAS has been considered as being implausible to target for decades. Chemotherapy was the initial recommended therapy for KRAS-mutant cancer patients, which was then replaced by or combined with immunotherapy. KRAS G12C inhibitors became the most recent breakthrough in targeted therapy, with Sotorasib being approved by the Food and Drug Administration (FDA) based on its significant efficacy in multiple clinical studies. However, the subtypes of the KRAS mutations are complex, and the development of inhibitors targeting non-G12C subtypes is still at a relatively early stage. In addition, the monotherapy of KRAS inhibitors has accumulated possible resistance, acquiring the exploration of combination therapies or next-generation KRAS inhibitors. Thus, other non-target, conventional therapies have also been considered as being promising. Here in this review, we went through the characteristics of KRAS mutations in cancer patients, and the prognostic effect that it poses on different therapies and advanced therapeutic strategy, as well as cutting-edge research on the mechanisms of drug resistance, tumor development, and the immune microenvironment.

The integrative analysis based on super-enhancer related genes for predicting different subtypes and prognosis of patient with lower-grade glioma

Objective: Emerging evidence revealed that super-enhancer plays a crucial role in the transcriptional reprogramming for many cancers. The purpose aimed to explored how the super-enhancer related genes affects the prognosis and tumor immune microenvironment (TIME) of patients with low-grade glioma (LGG). Methods: In this study, the differentially expressed genes (DEGs) between LGG cohorts and normal brain tissue cohort were identified by the comprehensive analysis of the super-enhancer (SE) related genes. Then non-negative matrix factorization was performed to seek the optimal classification based on the DEGs, while investigating prognostic and clinical differences between different subtypes. Subsequently, a prognostic related signature (SERS) was constructed for the comprehensive evaluation in term of individualized prognosis, clinical characteristics, cancer markers, genomic alterations, and immune microenvironment of patients with LGG. Results: Based on the expression profiles of 170 DEGs, we identified three SE subtypes, and the three subtypes showed significant differences in prognostic, clinicopathological features. Then, nine optimal SE-related genes were selected to construct the SERS through the least absolute shrinkage and selection operator Cox regression analysis. Survival analysis showed that SERS had strong and stable predictive ability for the prognosis of LGG patients in the The Cancer Genome Atlas, China Glioma Genome Atlas, and Remdrandt cohorts, respectively. We also found that SERS was highly correlated with clinicopathological features, tumor immune microenvironment, cancer hallmarks, and genomic alterations in LGG patients. In addition, the predictive power of SERS for immune checkpoint inhibitor treatment is also superior. The qRT-PCR results and immunohistochemical results also confirmed the difference in the expression of four key genes in normal cells and tumors, as well as in normal tissues and tumor tissues. Conclusion: The SERS could be suitable to utilize individualized prognosis prediction and immunotherapy options for LGG patients in clinical application.

RAS oncogenic activity predicts response to chemotherapy and outcome in lung adenocarcinoma

Activating mutations in KRAS occur in 32% of lung adenocarcinomas (LUAD). Despite leading to aggressive disease and resistance to therapy in preclinical studies, the KRAS mutation does not predict patient outcome or response to treatment, presumably due to additional events modulating RAS pathways. To obtain a broader measure of RAS pathway activation, we developed RAS84, a transcriptional signature optimised to capture RAS oncogenic activity in LUAD. We report evidence of RAS pathway oncogenic activation in 84% of LUAD, including 65% KRAS wild-type tumours, falling into four groups characterised by coincident alteration of STK11/LKB1, TP53 or CDKN2A, suggesting that the classifications developed when considering only KRAS mutant tumours have significance in a broader cohort of patients. Critically, high RAS activity patient groups show adverse clinical outcome and reduced response to chemotherapy. Patient stratification using oncogenic RAS transcriptional activity instead of genetic alterations could ultimately assist in clinical decision-making.

Biomarkers of related driver genes predict anti-tumor efficacy of immune checkpoint inhibitors

Cancer is a disease with high morbidity and mortality in the world. In the past, the main treatment methods for cancer patients were surgery, radiotherapy and chemotherapy. However, with early treatment, the recurrence rate of cancer is higher, and the drug resistance of cancer cells is faster. In recent years, with the discovery of immune escape mechanism of cancer cells, Immunotherapy, especially Immune Checkpoint Inhibitors (ICIs), has made a breakthrough in the treatment of solid tumors, significantly prolonging the overall survival time and disease-free progression in some solid tumors, and its clinical benefits are more prominent than those of traditional anti-tumor drugs, which has become the hope of cancer patients after the failure of multi-line therapy. More and more studies have shown that there is a correlation between cancer driving genes and the clinical benefits of ICIs treatment, and the therapeutic effects and adverse reactions of ICIs can be predicted by the status of driving genes. Therefore, screening potential biomarkers of people who may benefit from immunotherapy in order to maximize the therapeutic benefits is a top priority. This review systematically summarizes the cancer driving genes that may affect the clinical benefits of immune checkpoint inhibitors, and provides accurate scientific basis for clinical practice.

KRAS-G12D mutation drives immune suppression and the primary resistance of anti-PD-1/PD-L1 immunotherapy in non-small cell lung cancer

BACKGROUND

Although immune checkpoint inhibitors (ICIs) against programmed cell death protein 1 (PD-1) and its ligand PD-L1 have demonstrated potency towards treating patients with non-small cell lung carcinoma (NSCLC), the potential association between Kirsten rat sarcoma viral oncogene homolog (KRAS) oncogene substitutions and the efficacy of ICIs remains unclear. In this study, we aimed to find point mutations in the KRAS gene resistant to ICIs and elucidate resistance mechanism.

METHODS

The association between KRAS variant status and the efficacy of ICIs was explored with a clinical cohort (n = 74), and confirmed with a mouse model. In addition, the tumor immune microenvironment (TIME) of KRAS-mutant NSCLC, such as CD8⁺ tumor-infiltrating lymphocytes (TILs) and PD-L1 level, was investigated. Cell lines expressing classic KRAS substitutions were used to explore signaling pathway activation involved in the formation of TIME. Furthermore, interventions that improved TIME were developed to increase responsiveness to ICIs.

RESULTS

We observed the inferior efficacy of ICIs in KRAS-G12D-mutant NSCLC. Based upon transcriptome data and immunostaining results from KRAS-mutant NSCLC, KRAS-G12D point mutation negatively correlated with PD-L1 level and secretion of chemokines CXCL10/CXCL11 that led to a decrease in CD8⁺ TILs, which in turn yielded an immunosuppressive TIME. The analysis of cell lines overexpressing classic KRAS substitutions further revealed that KRAS-G12D mutation suppressed PD-L1 level via the P70S6K/PI3K/AKT axis and reduced CXCL10/CXCL11 levels by down-regulating high mobility group protein A2 (HMGA2) level. Notably, paclitaxel, a chemotherapeutic agent, upregulated HMGA2 level, and in turn, stimulated the secretion of CXCL10/CXCL11. Moreover, PD-L1 blockade combined with paclitaxel significantly suppressed tumor growth compared with PD-L1 inhibitor monotherapy in a mouse model with KRAS-G12D-mutant lung adenocarcinoma. Further analyses revealed that the combined treatment significantly enhanced the recruitment of CD8⁺ TILs via the up-regulation of CXCL10/CXCL11 levels. Results of clinical study also revealed the superior efficacy of chemo-immunotherapy in patients with KRAS-G12D-mutant NSCLC compared with ICI monotherapy.

CONCLUSIONS

Our study elucidated the molecular mechanism by which KRAS-G12D mutation drives immunosuppression and enhances resistance of ICIs in NSCLC. Importantly, our findings demonstrate that ICIs in combination with chemotherapy may be more effective in patients with KRAS-G12D-mutant NSCLC.

Efficacy of first‐line immune checkpoint inhibitors in patients with advanced NSCLC with KRAS , MET , FGFR , RET , BRAF , and HER2 alterations

Background

In patients with non‐small cell lung cancer (NSCLC) harboring driver alterations, the efficacy of immune checkpoint inhibitors (ICIs) remains uncertain. Our study aimed to examine the first‐line ICI efficacy in patients with NSCLC harboring KRAS, MET, FGFR, RET, BRAF, and HER2 alterations in a real‐world setting.

Methods

This single‐center, retrospective cohort study included patients with advanced NSCLC harboring KRAS, MET, FGFR, RET, BRAF, HER2 alterations or driver‐negative, and were treated with first‐line ICI therapy. Best overall response, progression‐free survival (PFS), and overall survival (OS) were evaluated.

Results

Seventy‐eight patients with NSCLC were included (median age, 72 years): 67% were men, 15% were never‐smokers, and 83% had adenocarcinoma. The driver alterations involved KRAS (n = 21), MET (n = 6), FGFR (n = 3), RET (n = 2), BRAF (n = 2), HER2 (n = 1), and driver‐negative (n = 43). The partial responses for KRAS, MET, FGFR, RET, BRAF, HER2, and driver‐negative were 57%, 50%, 100%, 50%, 100%, 0%, and 47%, respectively. The median PFS (months) was 16.2 (95% confidence interval [CI]: 6.3– not reached [NR]) for KRAS, 2.8 (95% CI: 2.7–NR) for MET, 11.7 (95% CI: 5.9–NR) for other alterations (FGFR, RET, BRAF, and HER2), and 10.0 (95% CI: 3.7–14.3) for driver‐negative, respectively. The median OS (months) was 31.3 (95% CI: 9.0–NR) for KRAS, not reached for MET, 23.5 (95% CI: 18.3–NR) for other alterations, and 21.1 (95% CI: 15.2–NR) for driver‐negative, respectively.

Conclusions

The benefit of the first‐line ICI was similar in advanced NSCLC regardless of the driver alterations, except for MET alterations.

Survival Prediction of Patients Treated With Immune Checkpoint Inhibitors via KRAS/TP53/EGFR-Single Gene Mutation

Background: Immune checkpoint inhibitors (ICIs) have become an effective treatment option for cancer. KRAS, EGFR and TP53 are common mutated oncogenes in cancer whose single gene status may predict the therapeutic effect of clinical ICIs. In this efficacy evaluation, we aimed to clarify whether the single gene mutation status of KRAS, EGFR or TP53 affects the survival benefits of ICIs in cancer patients.

Methods: We used PubMed, Cochrane Library, web of science, and clinical trials Gov database to retrieve qualified documents, the time was up to January 2022. Hazard ratios (HRS) and 95% confidence intervals (CIs) were used to determine the single gene mutation status and no progression of KRAS, EGFR or TP53.

Results: A total of 19 studies included 7029 cancer patients treated with ICIs. The results showed that KRAS, EGFR or TP53 single gene mutation could significantly improve PFS and OS in patients receiving ICIs, but the degree of improvement was different. The risk of prolongation of PFS (HR = 1.48, 95% CI = 1.19-1.85, p = 0.0004) and OS (HR = 1.68, 95% CI = 1.36-2.07, p < 0.00001) caused by TP53 single gene mutation was relatively high, the risk ratio of prolongation of PFS (HR = 1.38, 95% CI = 1.21-1.57, p < 0.00001) and OS (HR = 1.56, 95% CI = 1.20-2.04, p = 0.001) caused by EGFR single gene mutation was the second, the risk ratio of prolongation of PFS (HR = 1.33, 95% CI = 1.12-1.57, p = 0.001) and OS (HR = 1.39, 95% CI = 1.18-1.63, p < 0.00001) caused by KRAS single gene mutation was relatively low, and the results were significantly different.

Conclusion: In cancer patients, KRAS, EGFR or TP53 single gene status is correlated with the benefits of immunotherapy PFS and OS, which suggests that gene sequencing should be carried out in time in the process of clinical treatment to determine the gene mutation of patients and better predict the clinical treatment effect of ICIs.

Predictive Markers for Immune Checkpoint Inhibitors in Non-Small Cell Lung Cancer

Immune checkpoint inhibitors (ICIs) have dramatically improved the outcomes of non-small cell lung cancer patients and have increased the possibility of long-term survival. However, few patients benefit from ICIs, and no predictive biomarkers other than tumor programmed cell death ligand 1 (PD-L1) expression have been established. Hence, the identification of biomarkers is an urgent issue. This review outlines the current understanding of predictive markers for the efficacy of ICIs, including PD-L1, tumor mutation burden, DNA mismatch repair deficiency, microsatellite instability, CD8⁺ tumor-infiltrating lymphocytes, human leukocyte antigen class I, tumor/specific genotype, and blood biomarkers such as peripheral T-cell phenotype, neutrophil-to-lymphocyte ratio, interferon-gamma, and interleukin-8. A tremendous number of biomarkers are in development, but individual biomarkers are insufficient. Tissue biomarkers have issues in reproducibility and accuracy because of intratumoral heterogeneity and biopsy invasiveness. Furthermore, blood biomarkers have difficulty in reflecting the tumor microenvironment and therefore tend to be less predictive for the efficacy of ICIs than tissue samples. In addition to individual biomarkers, the development of composite markers, including novel technologies such as machine learning and high-throughput analysis, may make it easier to comprehensively analyze multiple biomarkers.

Single Circulating-Tumor-Cell-Targeted Sequencing to Identify Somatic Variants in Liquid Biopsies in Non-Small-Cell Lung Cancer Patients

Non-small-cell lung cancer (NSCLC) accounts for most cancer-related deaths worldwide. Liquid biopsy by a blood draw to detect circulating tumor cells (CTCs) is a tool for molecular profiling of cancer using single-cell and next-generation sequencing (NGS) technologies. The aim of the study was to identify somatic variants in single CTCs isolated from NSCLC patients by targeted NGS. Thirty-one subjects (20 NSCLC patients, 11 smokers without cancer) were enrolled for blood draws (7.5 mL). CTCs were identified by immunofluorescence, individually retrieved, and DNA-extracted. Targeted NGS was performed to detect somatic variants (single-nucleotide variants (SNVs) and insertions/deletions (Indels)) across 65 oncogenes and tumor suppressor genes. Cancer-associated variants were classified using OncoKB database. NSCLC patients had significantly higher CTC counts than control smokers (p = 0.0132; Mann–Whitney test). Analyzing 23 CTCs and 13 white blood cells across seven patients revealed a total of 644 somatic variants that occurred in all CTCs within the same subject, ranging from 1 to 137 per patient. The highest number of variants detected in ≥1 CTC within a patient was 441. A total of 18/65 (27.7%) genes were highly mutated. Mutations with oncogenic impact were identified in functional domains of seven oncogenes/tumor suppressor genes (NF1, PTCH1, TP53, SMARCB1, SMAD4, KRAS, and ERBB2). Single CTC-targeted NGS detects heterogeneous and shared mutational signatures within and between NSCLC patients. CTC single-cell genomics have potential for integration in NSCLC precision oncology.

Targeting KRAS in Non-Small Cell Lung Cancer

Kirsten Rat Sarcoma viral oncogene homolog (KRAS) is the most frequently altered oncogene in Non-Small Cell Lung Cancer (NSCLC). KRAS mutant tumors constitute a heterogeneous group of diseases, different from other oncogene-derived tumors in terms of biology and response to treatment, which hinders the development of effective drugs against KRAS. Therefore, for decades, despite enormous efforts invested in the development of drugs aimed at inhibiting KRAS or its signaling pathways, KRAS was considered to be undruggable. Recently, the discovery of a new pocket under the effector binding switch II region of KRAS G12C has allowed the development of direct KRAS inhibitors such as sotorasib, the first FDA-approved drug targeting KRAS G12C, or adagrasib, initiating a new exciting era. However, treatment with targeted KRAS G12C inhibitors also leads to resistance, and understanding the possible mechanisms of resistance and which drugs could be useful to overcome it is key. Among others, KRAS G12C (ON) tricomplex inhibitors and different combination therapy strategies are being analyzed in clinical trials. Another area of interest is the potential role of co-mutations in treatment selection, particularly immunotherapy. The best first-line strategy remains to be determined and, due to the heterogeneity of KRAS, is likely to be based on combination therapies.

Oncogenic KRAS blockade therapy: renewed enthusiasm and persistent challenges

Across a broad range of human cancers, gain-of-function mutations in RAS genes (HRAS, NRAS, and KRAS) lead to constitutive activity of oncoproteins responsible for tumorigenesis and cancer progression. The targeting of RAS with drugs is challenging because RAS lacks classic and tractable drug binding sites. Over the past 30 years, this perception has led to the pursuit of indirect routes for targeting RAS expression, processing, upstream regulators, or downstream effectors. After the discovery that the KRAS-G12C variant contains a druggable pocket below the switch-II loop region, it has become possible to design irreversible covalent inhibitors for the variant with improved potency, selectivity and bioavailability. Two such inhibitors, sotorasib (AMG 510) and adagrasib (MRTX849), were recently evaluated in phase I-III trials for the treatment of non-small cell lung cancer with KRAS-G12C mutations, heralding a new era of precision oncology. In this review, we outline the mutations and functions of KRAS in human tumors and then analyze indirect and direct approaches to shut down the oncogenic KRAS network. Specifically, we discuss the mechanistic principles, clinical features, and strategies for overcoming primary or secondary resistance to KRAS-G12C blockade.

Immunotherapy and Vaccination in Surgically Resectable Non-Small Cell Lung Cancer (NSCLC)

Early-stage NSCLC (stages I and II, and some IIIA diseases) accounts for approximately 30% of non-small cell lung cancer (NSCLC) cases, with surgery being its main treatment modality. The risk of disease recurrence and cancer-related death, however, remains high among NSCLC patients after complete surgical resection. In previous studies on the long-term follow-up of post-operative NSCLC, the results showed that the five-year survival rate was about 65% for stage IB and about 35% for stage IIIA diseases. Platinum-based chemotherapy with or without radiation therapy has been used as a neoadjuvant therapy or post-operative adjuvant therapy in NSCLC, but the improvement of survival is limited. Immune checkpoint inhibitors (ICIs) have effectively improved the 5-year survival of advanced NSCLC patients. Cancer vaccination has also been explored and used in the prevention of cancer or reducing disease recurrence in resected NSCLC. Here, we review studies that have focused on the use of immunotherapies (i.e., ICIs and vaccination) in surgically resectable NSCLC. We present the results of completed clinical trials that have used ICIs as neoadjuvant therapies in pre-operative NSCLC. Ongoing clinical trials investigating ICIs as neoadjuvant and adjuvant therapies are also summarized.