The role of molecular heterogeneity targeting resistance mechanisms to lung cancer therapies

Debate on first-line treatment strategies in advanced non-small cell lung cancer with EGFR mutation: An expert panel meeting by the Italian Association of Thoracic Oncology (AIOT)

BACKGROUND

The front-line treatment options and regulatory approval scenario for epidermal growth factor receptor (EGFR) mutation positive metastatic non-small cell lung cancer (NSCLC) have rapidly evolved in the recent months, with newly presented positive trial results of novel compounds and combination strategies in the setting of common activating mutations, uncommon mutations, and exon 20 insertions. In this context, international lively debate is emerging on how to choose among the available regimens, based on efficacy and safety results.

METHODS

A virtual International Expert Panel was held in July 2024 to review data on front-line regimens in patients with NSCLC harboring EGFR mutations, including common, uncommon and exon 20 insertions. The panel discussed available evidence, and reached common considerations for clinical practice and clinical research.

RESULTS

In the setting of EGFR common activating mutations, all panelists agreed that single agent osimertinib, the combination of osimertinib with platinum-pemetrexed, and the combination of amivantamab and lazertinib, are first-line treatment options. Overall, panelists defined characteristics of patients in which combination treatments should be avoided. Subsequent treatment strategies at disease progression were discussed according to the different front-line options. With regards to uncommon EGFR mutations, panelists agreed that afatinib remains the only drug with phase 3 results available, and that afatinib and osimertinib are the preferred first-line options. In EGFR exon20 insertion positive disease, the combination of carboplatin, pemetrexed and amivantamab has been identified as the preferred front-line treatment, with second-line amivantamab to be used in the second-line setting whenever not available in front-line. The panelists defined priorities in clinical research, with high priority attributed to investigating resistance mechanisms, novel generation of tyrosine kinase inhibitors, and selection biomarkers.

CONCLUSIONS

Different toxicity profiles and sequential strategies were considered, together with efficacy results, to reach common considerations for the front-line treatment strategies in EGFR mutant NSCLC, however clinical research should be prioritized to identify further selection features.

Advancements in fourth-generation EGFR TKIs in EGFR-mutant NSCLC: Bridging biological insights and therapeutic development

Third-generation EGFR tyrosine kinase inhibitor (TKIs) have revolutionized the treatment landscape for patients with non-small cell lung cancer (NSCLC) harboring EGFR activating mutations, with improved long-term outcomes compared to first-generation TKIs. Nevertheless, disease progression inevitably occurs, limiting osimertinib long-term efficacy. Indeed, the molecular biology underlying acquired resistance to first-line osimertinib is multifaceted and includes the emergence of on-target and off-target alterations. EGFR-C797S mutation represents the most frequent mechanism of on-target resistance and hinders drug binding to the target site. EGFR-independent resistance includes the activation of alternative signaling pathways, such as MET amplification and HER2 mutations, and histological transformation. In this setting, chemotherapy is the current therapeutic option, with modest clinical outcomes. Therefore, the development of novel therapeutic strategies to overcome resistance to osimertinib is a major challenge. In this setting, fourth-generation TKIs are emerging as an interesting therapeutic option to overcome on-target resistance. Preclinical drug development has led to the discovery of thiazole-amid inhibitors, which activity is mediated by the allosteric inhibition of EGFR, resulting in high specificity towards mutant-EGFR. Early phase 1/2 clinical trials are ongoing to elucidate their activity also in the clinical setting. Aim of this review is to provide a state-of-the-art analysis on preclinical development of fourth-generation EGFR-TKIs and promising preliminary clinical data.

Co-Occurring Driver Genomic Alterations in Advanced Non-Small-Cell Lung Cancer (NSCLC): A Retrospective Analysis

Background: Actionable driver mutations account for 40-50% of NSCLC cases, and their identification clearly affects treatment choices and outcomes. Conversely, non-actionable mutations are genetic alterations that do not currently have established treatment implications. Among co-occurring alterations, the identification of concurrent actionable genomic alterations is a rare event, potentially impacting prognosis and treatment outcomes. Methods: We retrospectively evaluated the prevalence and patterns of concurrent driver genomic alterations in a large series of NSCLCs to investigate their association with clinicopathological characteristics, to assess the prognosis of patients whose tumor harbors concurrent alterations in the genes of interest and to explore their potential therapeutic implications. Results: Co-occurring driver alterations were identified in 26 out of 1520 patients with at least one gene alteration (1.7%). Within these cases, the incidence of concurrent actionable gene alterations was 39% (0.7% of the overall cohort). Among compound actionable gene mutations, EGFR was the most frequently involved gene (70%). The most frequent association was EGFR mutations with ROS1 rearrangement. Front-line targeted treatments were the preferred approach in patients with compound actionable mutations, with dismal median PFS observed (6 months). Conclusions: Advances in genomic profiling technologies are facilitating the identification of concurrent mutations. In patients with concurrent actionable gene alterations, integrated molecular and clinical data should be used to guide treatment decisions, always considering rebiopsy at the moment of disease progression.

Post-Progression Analysis of EGFR-Mutant NSCLC Following Osimertinib Therapy in Real-World Settings

BACKGROUND

Platinum-based chemotherapy is the current standard treatment option in patients with EGFR-mutant non-small-cell lung cancer (NSCLC) who progress on osimertinib. However, outcomes with chemotherapy are dismal, and the treatment of central nervous system (CNS) disease is an unmet need in this setting.

METHODS

Patients with EGFR-mutant NSCLC who were candidates to receive osimertinib in the metastatic setting at our Center from 2015 to 2022 were retrospectively evaluated to identify patients who received standard platinum-based chemotherapy post-osimertinib. Data were collected on treatment outcomes, with a focus on brain metastases and progression patterns.

RESULTS

A total of 220 patients received indication for osimertinib in the study period; n = 176 had adequate follow-up data. Overall, n = 117 patients experienced disease progression on osimertinib. The median time to osimertinib progressive disease (PD) was 15 months (95% confidence interval CI 13-18). Of them, 51 patients (45%) had no access to further treatments. Of the remaining patients, n = 8 received experimental treatments, and n = 55 received standard platinum-based chemotherapy and were considered for this study. Median duration of chemotherapy was 3 months (95% CI 2-5); the best responses among 53 evaluable patients were observed as follows: 15% partial response/complete response (PR/CR), 40% stable disease (SD), 45% PD. Median progression-free survival (PFS) and overall survival (OS) were 3 (95% CI 2-5) and 10 (95% CI 6-15) months, respectively. All patients had baseline and follow-up brain radiologic assessments, and n = 23 had brain metastases at the start of chemotherapy. With a median follow-up of 13 months, intracranial PD occurred in 47% patients, being the first site of PD in 59% of cases. The median time for intracranial (IC) PD was 2 months (95% CI 2-7). IC PD occurred as oligometastatic in 29%, whereas in 71% of cases, it was associated with systemic PD.

CONCLUSIONS

Access to subsequent treatments and CNS progression are confirmed unmet needs in EGFR-mutant NSCLC patients. Clinical and CNS-specific outcomes in patients receiving standard chemotherapy after the failure of osimertinib are dismal. Novel upfront treatment options with demonstrated prolonged PFS and better CNS outcomes may help address this important issue.

New Generations of Tyrosine Kinase Inhibitors in Treating NSCLC with Oncogene Addiction: Strengths and Limitations

Tyrosine kinase inhibitors (TKIs) revolutionized the treatment of patients with advanced or metastatic non-small cell lung cancer (NSCLC) harboring most driver gene alterations. Starting from the first generation, research rapidly moved to the development of newer, more selective generations of TKIs, obtaining improved results in terms of disease control and survival. However, the use of novel generations of TKIs is not without limitations. We reviewed the main results obtained, as well as the ongoing clinical trials with TKIs in oncogene-addicted NSCLC, together with the biology underlying their potential strengths and limitations. Across driver gene alterations, novel generations of TKIs allowed delayed resistance, prolonged survival, and improved brain penetration compared to previous generations, although with different toxicity profiles, that generally moved their use from further lines to the front-line treatment. However, the anticipated positioning of novel generation TKIs leads to abolishing the possibility of TKI treatment sequencing and any role of previous generations. In addition, under the selective pressure of such more potent drugs, resistant clones emerge harboring more complex and hard-to-target resistance mechanisms. Deeper knowledge of tumor biology and drug properties will help identify new strategies, including combinatorial treatments, to continue improving results in patients with oncogene-addicted NSCLC.

Immune checkpoint inhibitors in EGFR-mutant non-small cell lung cancer: A systematic review

BACKGROUND

Since their first introduction in clinical practice, immune checkpoint inhibitors showed limited benefit in patients with NSCLC harboring EGFR mutations. With the rationale of increasing immune activation, combinatorial ICI strategies have been evaluated also in this subgroup of patients.

METHODS

We performed a systematic review on efficacy of ICI-based strategies in EGFR-mutant NSCLC according to most updated evidence.

RESULTS

Overall, ICI monotherapy and ICI plus chemotherapy confirm to be ineffective in EGFR-mutant NSCLC, whereas the combination of ICI with antiangiogenic and chemotherapy showed promising results. Limited data are available with alternative ICI combination strategies, driven by strong biological rationale of modulating the tumor immune microenvironment.

CONCLUSIONS

To date, the available evidence do not support the use of ICI in patients with NSCLC harboring EGFR mutations. Clinical trials are ongoing to define which is the best timing and exploring novel combinations with ICI in this specific disease.

Liquid biopsy from research to clinical practice: focus on non-small cell lung cancer

INTRODUCTION

In the current era of personalized medicine, liquid biopsy has acquired a relevant importance in patient management of advanced stage non-small cell lung cancer (NSCLC). As a matter of fact, liquid biopsy may supplant the problem of inadequate tissue for molecular testing. The term 'liquid biopsy' refers to a number of different biological fluids, but is most clearly associated with plasma-related platforms. It must be taken into account that pre-analytical processing and the selection of the appropriate technology according to the clinical context may condition the results obtained. In addition, novel clinical applications beyond the evaluation of the molecular status of predictive biomarkers are currently under investigation.

AREAS COVERED

This review summarizes the available evidence on pre-analytical issues and different clinical applications of liquid biopsies in NSCLC patients.

EXPERT OPINION

Liquid biopsy should be considered not only as a valid alternative but as complementary to tissue-based molecular approaches. Careful attention should be paid to the optimization and standardization of all phases of liquid biopsy samples management in order to determine a significant improvement in either sensitivity or specificity, while significant reducing the number of 'false negative' or 'false positive' molecular results.