Prognostic Characteristics and Immunotherapy Response of Patients With Nonsquamous NSCLC With Kras Mutation in East Asian Populations: A Single-Center Cohort Study in Taiwan

Dissecting the Clinical Characteristics and Treatment Outcomes Correlates of KRAS G12C-Mutated Non-Small Cell Lung Cancer

Background

KRAS mutation is one of the most common driver oncogenes in non-small cell lung cancer (NSCLC), and the most common mutation subtype is G12C. However, there is still a lack of efficacy and prognosis data related to immunotherapy, which hinders the promotion of new strategies.

Methods

Clinical characteristics and treatment outcomes were collected and analyzed for patients with NSCLC harboring KRAS mutations at West China Hospital of Sichuan University from June 2013 to March 2023.

Results

Among the 231 patients with KRAS-mutated NSCLC, 29.4% had KRAS G12C mutations. Compared to the KRAS non-G12C NSCLC group, the KRAS G12C NSCLC group had a greater number of pack-years. The programmed death ligand 1 expression and the proportion of patients with a high tumor mutational burden were not significantly different between the two groups. Similar patterns of TP53, STK11, and CDKN2A mutations were observed between KRAS G12C and KRAS non-G12C NSCLC groups. The median progression-free survival (PFS) (8.4 vs 7.0 months, p=0.100) and overall survival (OS) (12.1 vs 18.1 months, p=0.590) were not statistically different between KRAS G12C and KRAS non-G12C. Compared to patients with KRAS G12C NSCLC who did not receive immunotherapy, patients who received immunotherapy had a better objective response rate (46.2% vs 0%, p=0.002), PFS (12.2 vs 7.5 months, p=0.087) and OS (49.9 vs 11.1 months, p=0.12).

Conclusion

Patients with KRAS G12C were more likely to be smokers. Advanced KRAS G12C NSCLC patients who received immunotherapy had a better ORR than those who did not, suggesting that patients with G12C mutations are more likely to benefit from immunotherapy.

Prognostic value of KRAS G12C in advanced non-small cell lung cancer with high PD-L1 expression treated with upfront immunotherapy: a systematic review and meta-analysis

AIM

This study aims to evaluate the prognostic role of the KRAS G12C mutation in patients with advanced non-small cell lung cancer and PD-L1 expression ≥50% who are treated with immune checkpoint inhibitor monotherapy.

METHODS

We conducted a systematic review of clinical studies fulfilling the following criteria: (1) enrolling patients with advanced/metastatic non-small cell lung cancer with high PD-L1 tumour expression receiving first-line therapy with anti-PD-(L)1 immune checkpoint inhibitors; (2) comparing the outcomes of patients with the KRAS G12C mutation to those without this mutation, and (3) reporting overall survival and progression-free survival (PFS). The electronic databases Medline, EMBASE, Cochrane and Google Scholar, along with reference lists, were systematically searched.

RESULTS

We identified four publications that fulfilled the inclusion criteria, comprising a total of 469 patients. Of these, two studies reported hazard ratios (HR) for PFS, resulting in a final pooled patient sample of 163 for the meta-analysis. In patients with non-small cell lung cancer who received anti-PD-(L)1 monotherapy, the presence of a KRAS G12C mutation was associated with improved PFS compared to patients with KRAS wild-type tumours, with a pooled hazard ratio of 0.39 and a 95% Confidence Interval (CI) of 0.25-0.63. Among all patients with KRAS mutations, those harbouring a KRAS G12C mutation had improved PFS compared to patients with any other KRAS mutation (pooled HR 0.33, 95% CI 0.19-0.57).

CONCLUSIONS

Patients with non-small cell lung cancer who have the KRAS G12C mutation and high PD-L1 expression demonstrate favourable PFS with first-line PD-(L)1 immune checkpoint inhibitor monotherapy compared to patients with KRASwt or other KRAS mutations and high PD-L1 expression.

Targeting KRASG12C in Non-Small-Cell Lung Cancer: Current Standards and Developments

Among the most common molecular alterations detected in non-small-cell lung cancer (NSCLC) are mutations in Kristen Rat Sarcoma viral oncogene homolog (KRAS). KRAS mutant NSCLC is a heterogenous group of diseases, different from other oncogene-driven tumors in terms of biology and response to therapies. Despite efforts to develop drugs aimed at inhibiting KRAS or its signaling pathways, KRAS had remained undruggable for decades. The discovery of a small pocket in the binding switch II region of KRASG12C has revolutionized the treatment of KRASG12C-mutated NSCLC patients. Sotorasib and adagrasib, direct KRASG12C inhibitors, have been approved by the US Food and Drug Administration (FDA) and other regulatory agencies for patients with previously treated KRASG12C-mutated NSCLC, and these advances have become practice changing. However, first-line treatment in KRASG12C-mutated NSCLC does not differ from NSCLC without actionable driver genomic alterations. Treatment with KRASG12C inhibitors is not curative and patients develop progressive disease, so understanding associated mechanisms of drug resistance is key. New KRASG12C inhibitors and several combination therapy strategies, including with immune checkpoint inhibitors, are being studied in clinical trials. The aim of this review is to explore the clinical impact of KRAS, and outline different treatment approaches, focusing on the novel treatment of KRASG12C-mutated NSCLC.

KRAS G12C in advanced NSCLC: Prevalence, co-mutations, and testing

KRAS is the most commonly mutated oncogene in advanced, non-squamous, non-small cell lung cancer (NSCLC) in Western countries. Of the various KRAS mutants, KRAS G12C is the most common variant (~40%), representing 10-13% of advanced non-squamous NSCLC. Recent regulatory approvals of the KRASG12C-selective inhibitors sotorasib and adagrasib for patients with advanced or metastatic NSCLC harboring KRASG12C have transformed KRAS into a druggable target. In this review, we explore the evolving role of KRAS from a prognostic to a predictive biomarker in advanced NSCLC, discussing KRAS G12C biology, real-world prevalence, clinical relevance of co-mutations, and approaches to molecular testing. Real-world evidence demonstrates significant geographic differences in KRAS G12C prevalence (8.9-19.5% in the US, 9.3-18.4% in Europe, 6.9-9.0% in Latin America, and 1.4-4.3% in Asia) in advanced NSCLC. Additionally, the body of clinical data pertaining to KRAS G12C co-mutations such as STK11, KEAP1, and TP53 is increasing. In real-world evidence, KRAS G12C-mutant NSCLC was associated with STK11, KEAP1, and TP53 co-mutations in 10.3-28.0%, 6.3-23.0%, and 17.8-50.0% of patients, respectively. Whilst sotorasib and adagrasib are currently approved for use in the second-line setting and beyond for patients with advanced/metastatic NSCLC, testing and reporting of the KRAS G12C variant should be included in routine biomarker testing prior to first-line therapy. KRAS G12C test results should be clearly documented in patients' health records for actionability at progression. Where available, next-generation sequencing is recommended to facilitate simultaneous testing of potentially actionable biomarkers in a single run to conserve tissue. Results from molecular testing should inform clinical decisions in treating patients with KRAS G12C-mutated advanced NSCLC.

KRAS G12 isoforms exert influence over up-front treatments: A retrospective, multicenter, Italian analysis of the impact of first-line immune checkpoint inhibitors in an NSCLC real-life population

BACKGROUND

KRAS is commonly mutated in non-small cell lung cancer (NSCLC); however, the prognostic and predictive impact of each G12 substitution has not been fully elucidated. The approval of specific G12C inhibitors has modified the idea of KRAS "undruggability", and although the first-line standard consists of immune checkpoint inhibitors (ICIs) with or without chemotherapy, as suggested at ASCO 2022, the outcome in KRAS-mutated population is still controversial.

METHODS

We retrospectively described the clinical and pathological characteristics of a homogeneous G12 mutated cohort of 219 patients treated in four Italian oncologic units. We evaluated the outcome (PFS at 18 months and OS at 30 months) of those who underwent standard first-line treatment according to PD-L1 status, focusing on differences across single mutations.

RESULTS

In the study population, 47.9% of patients harbor the KRAS G12C mutation; 20.5%, G12V; 17.4%, G12D; and 8.2%, G12A. Smoking was a common behavior of patients harboring transversions and transition mutations. PD-L1 expression does not show particular distribution in the case series, although we recorded a prevalence of PD-L1 <1% in G12V (51.4%) compared to G12A (26.7%). ICIs alone was the clinician's choice in 32.7% of patients, and the chemo-immune combination in 17.3% of patients. We described the independent prognostic role of young age (p = 0.007), female gender (p = 0.016), and an ICI-based regimen (p = 0.034) regardless of mutations. Overall, our data confirm the worst prognostic value of G12V mutation apart from treatment choice unlike the other major mutations (C, D, and A) that showed a favorable trend in PFS.

CONCLUSIONS

KRAS G12 mutations are confirmed to have different characteristics, and the outcome is influenced by ICI first-line regimen. This study provides valuable information for further analysis in the future.

Light at the end of the tunnel: Clinical features and therapeutic prospects of KRAS mutant subtypes in non-small-cell lung cancer

Lung cancer is one of the most common causes of cancer-related deaths, and non-small-cell lung cancer (NSCLC) accounts for approximately 85% of all lung cancer cases. Kirsten rat sarcoma virus (KRAS), one of the three subtypes of the RAS family, is the most common oncogene involved in human cancers and encodes the key signaling proteins in tumors. Oncogenic KRAS mutations are considered the initiating factors in 30% of NSCLC cases, accounting for the largest proportion of NSCLC cases associated with driver mutations. Because effective inhibition of the related functions of KRAS with traditional small-molecule inhibitors is difficult, the KRAS protein is called an "undruggable target." However, in recent years, the discovery of a common mutation in the KRAS gene, glycine 12 mutated to cysteine (G12C), has led to the design and synthesis of covalent inhibitors that offer novel strategies for effective targeting of KRAS. In this review, we have summarized the structure, function, and signal transduction pathways of KRAS and discussed the available treatment strategies and potential treatment prospects of KRAS mutation subtypes (especially G12C, G12V, and G12D) in NSCLC, thus providing a reference for selecting KRAS mutation subtypes for the treatment of NSCLC.

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.

Economic Analysis of Tissue-First, Plasma-First, and Complementary NGS Approaches for Treatment-Naïve Metastatic Lung Adenocarcinoma

Background

To compare the testing costs and testing turnaround times of tissue-first, plasma-first, and complementary next-generation sequencing (NGS) approaches in patients with treatment-naïve metastatic lung adenocarcinoma.

Materials and Methods

We developed a decision tree model to compare three different approaches. Patients were entered into the model upon cancer diagnosis and those with both insufficient tissue specimens and negative liquid-based NGS were subjected to tissue re-biopsy. Actionable gene alterations with the U.S. Food and Drug Administration (FDA)-approved therapies included epidermal growth factor receptor (EGFR) mutation, anaplastic lymphoma kinase (ALK) gene rearrangement, ROS proto-oncogene 1 (ROS1) rearrangement, B-Raf proto-oncogene (BRAF) V600E mutation, rearranged during transfection (RET) gene rearrangement, mesenchymal-epithelial transition factor (MET) mutation, neurotrophic tyrosine receptor kinase (NTRK) gene rearrangement, K-Ras proto-oncogene (KRAS) G12C mutation, and human epidermal growth factor receptor 2 (HER2) mutation. Model outcomes were testing costs, testing turnaround times, and monetary losses taking both cost and time into consideration. We presented base-case results using probabilistic analysis. Stacked one-way and three-way sensitivity analyses were also performed.

Results

In terms of testing costs, tissue-first approach incurred US$2,354($1,963-$2,779) and was the most cost-efficient strategy. Complementary approach testing turnaround time (days) of 12.7 (10.8 to 14.9) was found as the least time-consuming strategy. Tissue-first, complementary, and plasma-first approaches resulted in monetary losses in USD of $4,745 ($4,010-$5,480), $6,778 ($5,923-$7,600), and $7,006 ($6,047-$7,964) respectively, and identified the same percentage of patients with appropriate FDA-approved therapies. Costs for liquid-based NGS, EGFR mutation rates, and quantity of tissue specimens were the major determinants in minimizing monetary loss. Plasma-first approach would be the preferable strategy if its testing price was reduced in USD to $818, $1,343, and $1,869 for populations with EGFR mutation rates of 30%, 45%, and 60% respectively.

Conclusion

The tissue-first approach is currently the best strategy in minimizing monetary loss. The complementary approach is an alternative for populations with a low EGFR mutation rate. The plasma-first approach becomes increasingly preferable as EGFR mutation rates gradually increase.

Genomic Landscape of Non-Small Cell Lung Cancer (NSCLC) in East Asia Using Circulating Tumor DNA (ctDNA) in Clinical Practice

Plasma-based next-generation sequencing (NGS) has demonstrated the potential to guide the personalized treatment of non-small cell lung cancer (NSCLC). Inherent differences in mutational genomic profiles of NSCLC exist between Asian and Western populations. However, the published mutational genomic data of NSCLC has largely focused on Western populations. We retrospectively analyzed results from comprehensive NGS of plasma (Guardant360^®) from patients with advanced non-squamous NSCLC, as seen in clinical practice. Tests were ordered between January 2016 and December 2020 in Hong Kong, Korea, Taiwan, Japan and Southeast Asia. The assay identified single-nucleotide variants (SNV), insertions and deletions, and fusions and amplifications in 74 genes. In total, 1608 plasma samples from patients with advanced non-squamous NSCLC were tested. The median turnaround time for test results was 7 days. Of the samples with detectable ctDNA (85.6%), 68.3% had alterations in at least one NCCN-recommended NSCLC biomarker. EGFR driver mutations were most frequent (48.6%), followed by alterations of KRAS (7.9%), ERBB2 (4.1%) and ALK (2.5%). Co-mutations of EGFR and KRAS occurred in 4.7% of samples. KRAS G12C was identified in 18.6% of all samples with KRAS mutations. Common mutations, such as exon 19 deletions and L858R, accounted for 88.4% of EGFR driver mutations. Among the samples with any EGFR driver mutation, T790M was present in 36.9%, including 7.7% with additional alterations associated with osimertinib resistance (MET amplification, C797X). Comprehensive plasma-based NGS provided the timely and clinically informative mutational genomic profiling of advanced non-squamous NSCLC in East Asian patients.

Clinical Characteristics and Outcomes in Advanced KRAS-Mutated NSCLC: A Multicenter Collaboration in Asia (ATORG-005)

Introduction

Whereas interpatient heterogeneity in clinical characteristics and treatment outcomes of NSCLC harboring a KRAS mutation is recognized, the characterization of these patients in Asia has been limited.

Methods

A multicenter, retrospective cohort study was conducted in eight academic centers across Asia. Patients diagnosed with advanced NSCLC harboring a KRAS mutation and who had received at least one line of anticancer therapy between January 2014 and December 2018 were included. Modified time to next treatment (TTNT) was adopted as a proxy for progression-free survival.

Results

A total of 216 patients were analyzed. The median age at diagnosis of advanced NSCLC was 63.3 years, 70.8% were men and 89.8% had adenocarcinoma. KRAS G12D was the most common subtype (25.5%), followed by G12C (24.5%), and G12V (19.4%) The proportion of current or former smokers was 65.7% in the overall population, with 86.8% in G12C and 58.9% in non-G12C subgroups. For all treatments combined for the total population, the first-line duration of therapy, modified TTNT, and TTNT were 4.5 (95% confidence interval: 3.4–5.9), 6.2 (4.9–8.8), and 9.5 (7.1–11.4) months, respectively. The median overall survival for the total population was 10.3 (6.9–12.4) months and was prolonged in patients ever treated with immunotherapy (14.6 [8.6–19.1] versus 7.0 [5.9–10.6] mo, hazard ratio = 0.54, p < 0.001), with left truncation to account for the time of KRAS testing.

Conclusions

Whereas treatment outcomes with conventional anticancer therapy are reasonable and immunotherapy looks promising, the unmet need remains high for patients with KRAS-mutated NSCLC in Asia, underscoring the need for novel therapeutic approaches.