Osimertinib versus osimertinib plus chemotherapy for non-small cell lung cancer with EGFR (T790M)-associated resistance to initial EGFR inhibitor treatment: An open-label, randomised phase 2 clinical trial

Non-small cell lung cancer: an update on emerging EGFR-targeted therapies

INTRODUCTION

Current research in EGFR-mutated NSCLC focuses on the management of drug resistance and uncommon mutations, as well as on the opportunity to extend targeted therapies' field of action to earlier stages of disease.

AREAS COVERED

We conducted a review analyzing literature from the PubMed database with the aim to describe the current state of art in the management of EGFR-mutated NSCLC, but also to explore new strategies under investigation. To this purpose, we collected recruiting phase II-III trials registered on Clinicaltrials.govand conducted on EGFR-mutated NSCLC both in early and advanced stage.

EXPERT OPINION

With this review, we want to provide an exhaustive overview of current and new potential treatments in EGFR-mutated NSCLC, with emphasis on the most promising newly investigated strategies, such as association therapies in the first-line setting involving EGFR-TKIs and chemotherapy (FLAURA2) or drugs targeting different driver pathways (MARIPOSA). We also aimed at unearthing challenges to achieve in this field, specifically the need to fully exploit already available compounds while developing new ones, the management of new emerging toxicities and the necessity to improve our biological understanding of the disease to design trials with a solid scientific rationale and to allow treatment personalization such in case of uncommon mutations.

Real-world osimertinib pretreatment experience in patients with epidermal growth factor receptor T790M mutation-positive locally advanced or metastatic non-small cell lung cancer

Osimertinib has demonstrated efficacy in patients with epidermal growth factor receptor (EGFR) T790M-positive non-small cell lung cancer (NSCLC) in clinical trials. However, real-world data on its effectiveness remain scarce. Taiwanese patients with T790M-positive locally advanced or metastatic NSCLC and progressive disease following treatment with at least one EGFR tyrosine kinase inhibitor (TKI) were enrolled from the osimertinib early access program. Of the 419 patients (mean age, 63 years; female, 67%), 53% were heavily pretreated (≥ third-line [3L]), making osimertinib a fourth-line (4L) intervention. The median progression-free survival (PFS) was 10.5 months (95% confidence interval [CI]: 8.95-11.41); the 18-month PFS rate was 26.5%. The median overall survival (OS) was 19.0 months (95% CI: 16.30-20.95); the 24-month OS rate was 40.9%. The objective response rate was 32.46%, and the disease control rate was 86.38%. The median time to treatment discontinuation of osimertinib monotherapy was 11.9 months (95% CI: 10.49-13.11). Subgroup analyses of median PFS and OS in the chemotherapy combination group vs. the osimertinib monotherapy group yielded no difference. Central nervous system (CNS) metastasis, number of prior lines of therapy, and types of initial EGFR-TKIs did not significantly impact outcomes. The median PFS values were 9.0 (95% CI: 5.18-11.34) and 10.9 (95% CI: 9.18-11.90) months with and without CNS metastasis, respectively, and 10.8 (95% CI: 8.59-12.69), 13.6 (95% CI: 10.89-16.3), and 9.2 (95% CI: 7.8-10.62) months for second-line (2L), 3L, and ≥4L therapy, respectively. In patients who received osimertinib as 2L therapy, the median PFS values in response to prior afatinib, erlotinib and gefitinib treatment were 11.2 (95% CI: 4.85-4.79), 10.5 (95% CI: 8.59-20.26) and 8.7 (95% CI: 7.21-16.79) months, respectively. Overall, real-world data from Taiwan support the clinical benefits of osimertinib in EGFR T790M -positive NSCLC.

Insights into the Overcoming EGFRDel19/T790M/C797S Mutation: A Perspective on the 2-Aryl-4-aminothienopyrimidine Backbone

The epithelial growth factor receptor (EGFR) signaling pathway has been proposed to benefit non-small cell lung cancer (NSCLC) treatment. In this manuscript, we investigated the modification of 2-aryl-4-aminoquinazoline, the classical backbone of the fourth-generation EGFR inhibitors, in addition to obtaining a series of novel 2-aryl-4-aminothienopyrimidine derivatives (A1~A45), we also gained further understanding of the modification of this framework. Derivatives were tested for cytotoxicity against cancer cell lines (cervical cancer cell line Hela, lung cancer cell lines A549, H1975, and PC-9, Ba/F3-EGFRDel19/T790M/C797S cells, and human normal hepatocytes LO2) as well as for the derivative's inhibitory activity against EGFRWT, EGFRL858R/T790M, and EGFRDel19/T790M/C797S kinase inhibitory activities. The results showed that most of the target compounds showed moderate to excellent activity against one or more cancer cell lines. Among them, the antitumor activity (IC50) of the most promising A9 against A549 and H1975 cell lines was 0.77±0.08 μM, 6.90±0.83 μM, respectively. At concentration of 10 μM, A9 can be employed as the fourth-generation of EGFR inhibitors with the ability to overcome the C797S drug resistance since it can suppress EGFRDel19/T790M/C797S cells and kinase by 98.90 % and 85.88 %, respectively. Moreover, the tumor-bearing nude mice experiment further shows that A9 can significantly inhibit the growth of tumor in vivo, with the tumor inhibition rate (TIR) of 55.92 %, which was equivalent to the positive group. After that, from the result of HE staining experiment and blood biochemical analysis experiment, A9 show low toxicity and good safety, which is worthy of further research and development.

PIK3CA mutation as an acquired resistance driver to EGFR-TKIs in non-small cell lung cancer: Clinical challenges and opportunities

Epithelial growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have significantly enhanced the treatment outcomes in non-small cell lung cancer (NSCLC) patients harboring EGFR mutations. However, the occurrence of acquired resistance to EGFR-TKIs is an unavoidable outcome observed in these patients. Disruption of the PI3K/AKT/mTOR signaling pathway can contribute to the emergence of resistance to EGFR TKIs in lung cancer. The emergence of PIK3CA mutations following treatment with EGFR-TKIs can lead to resistance against EGFR-TKIs. This review provides an overview of the current perspectives regarding the involvement of PI3K/AKT/mTOR signaling in the development of lung cancer. Furthermore, we outline the state-of-the-art therapeutic strategies targeting the PI3K/AKT/mTOR signaling pathway in lung cancer. We highlight the role of PIK3CA mutation as an acquired resistance mechanism against EGFR-TKIs in EGFR-mutant NSCLC. Crucially, we explore therapeutic strategies targeting PIK3CA-mediated resistance to EGFR TKIs in lung cancer, aiming to optimize the effectiveness of treatment.

DNA topoisomerase II inhibition potentiates osimertinib's therapeutic efficacy in EGFR-mutant non-small cell lung cancer models

Development of effective strategies to manage the inevitable acquired resistance to osimertinib, a third-generation EGFR inhibitor for the treatment of EGFR-mutant (EGFRm) non-small cell lung cancer (NSCLC), is urgently needed. This study reports that DNA topoisomerase II (Topo II) inhibitors, doxorubicin and etoposide, synergistically decreased cell survival, with enhanced induction of DNA damage and apoptosis in osimertinib-resistant cells; suppressed the growth of osimertinib-resistant tumors; and delayed the emergence of osimertinib-acquired resistance. Mechanistically, osimertinib decreased Topo IIα levels in EGFRm NSCLC cells by facilitating FBXW7-mediated proteasomal degradation, resulting in induction of DNA damage; these effects were lost in osimertinib-resistant cell lines that possess elevated levels of Topo IIα. Increased Topo IIα levels were also detected in the majority of tissue samples from patients with NSCLC after relapse from EGFR tyrosine kinase inhibitor treatment. Enforced expression of an ectopic TOP2A gene in sensitive EGFRm NSCLC cells conferred resistance to osimertinib, whereas knockdown of TOP2A in osimertinib-resistant cell lines restored their susceptibility to osimertinib-induced DNA damage and apoptosis. Together, these results reveal an essential role of Topo IIα inhibition in mediating the therapeutic efficacy of osimertinib against EGFRm NSCLC, providing scientific rationale for targeting Topo II to manage acquired resistance to osimertinib.

Amivantamab plus chemotherapy with and without lazertinib in EGFR-mutant advanced NSCLC after disease progression on osimertinib: primary results from the phase III MARIPOSA-2 study

BACKGROUND

Amivantamab plus carboplatin-pemetrexed (chemotherapy) with and without lazertinib demonstrated antitumor activity in patients with refractory epidermal growth factor receptor (EGFR)-mutated advanced non-small-cell lung cancer (NSCLC) in phase I studies. These combinations were evaluated in a global phase III trial.

PATIENTS AND METHODS

A total of 657 patients with EGFR-mutated (exon 19 deletions or L858R) locally advanced or metastatic NSCLC after disease progression on osimertinib were randomized 2 : 2 : 1 to receive amivantamab-lazertinib-chemotherapy, chemotherapy, or amivantamab-chemotherapy. The dual primary endpoints were progression-free survival (PFS) of amivantamab-chemotherapy and amivantamab-lazertinib-chemotherapy versus chemotherapy. During the study, hematologic toxicities observed in the amivantamab-lazertinib-chemotherapy arm necessitated a regimen change to start lazertinib after carboplatin completion.

RESULTS

All baseline characteristics were well balanced across the three arms, including by history of brain metastases and prior brain radiation. PFS was significantly longer for amivantamab-chemotherapy and amivantamab-lazertinib-chemotherapy versus chemotherapy [hazard ratio (HR) for disease progression or death 0.48 and 0.44, respectively; P < 0.001 for both; median of 6.3 and 8.3 versus 4.2 months, respectively]. Consistent PFS results were seen by investigator assessment (HR for disease progression or death 0.41 and 0.38 for amivantamab-chemotherapy and amivantamab-lazertinib-chemotherapy, respectively; P < 0.001 for both; median of 8.2 and 8.3 versus 4.2 months, respectively). Objective response rate was significantly higher for amivantamab-chemotherapy and amivantamab-lazertinib-chemotherapy versus chemotherapy (64% and 63% versus 36%, respectively; P < 0.001 for both). Median intracranial PFS was 12.5 and 12.8 versus 8.3 months for amivantamab-chemotherapy and amivantamab-lazertinib-chemotherapy versus chemotherapy (HR for intracranial disease progression or death 0.55 and 0.58, respectively). Predominant adverse events (AEs) in the amivantamab-containing regimens were hematologic, EGFR-, and MET-related toxicities. Amivantamab-chemotherapy had lower rates of hematologic AEs than amivantamab-lazertinib-chemotherapy.

CONCLUSIONS

Amivantamab-chemotherapy and amivantamab-lazertinib-chemotherapy improved PFS and intracranial PFS versus chemotherapy in a population with limited options after disease progression on osimertinib. Longer follow-up is needed for the modified amivantamab-lazertinib-chemotherapy regimen.

Real-world data on efficacy and safety of osimertinib in non-small cell lung cancer patients with EGFR T790M mutation detected by first and repeat rebiopsy

BACKGROUND

Osimertinib could effectively target epidermal growth factor receptor (EGFR) T790M resistance mutations in non-small cell lung cancer (NSCLC), indicating that rebiopsy may be particularly important. However, the clinical benefit of repeat rebiopsy in T790M-negative patients with NSCLC detected by the first rebiopsy is still unclear, and data on the efficacy and safety of osimertinib in patients with NSCLC who are T790M-positive patients on a repeat rebiopsy remain rare.

METHODS

We retrospectively collected the clinical data of advanced NSCLC patients with common EGFR mutation who were treated with 1/2-generation (1/2G) EGFR-tyrosine kinase inhibitors (TKIs) in first-line therapy in our center from January 2018 to December 2020. The detection rate of T790M by first and repeat rebiopsy was recorded, and we also analyzed the efficacy and safety of osimertinib for T790M-positive patients.

RESULTS

Among 190 common EGFR-mutant patients who received 1/2G EGFR-TKIs with advanced NSCLC in the first-line treatment, 141 patients developed progressive disease. In total, 110 of 141 accepted the first rebiopsy, with a T790M prevalence of 50.9% (56/110). In total, 43 T790M-positive patients who received osimertinib were included in first rebiopsy group. Of 54 T790M-negative patients detected by the first rebiopsy, 28 underwent repeated rebiopsy in subsequent clinical treatment, and 10 (35.7%) T790M-positive cases were confirmed. In total, eight T790M-positive patients treated with osimertinib were included in repeat rebiopsy group. Overall, 66 (60%) of 110 patients acquired a T790M mutation. In patients with the T790M mutation discovered by the first and repeat rebiopsy, osimertinib resulted in median progression-free survival of 7 (95% confidence interval [CI]: 5.3-8.7) and 6 (95% CI: 4.7-7.3) months, respectively (p = .656). The median overall survival since osimertinib initiation for T790M-positive patients at first rebiopsy was 20 (95% CI: 15.1-24.9) months and 19 (95% CI: 16.9-21.1) months, for those at repeated rebiopsy (p = .888). Adverse events of grade 3 or higher were similar in the two groups (25.6% vs. 12.5%, p = .616). There was no treatment-related death in the two groups.

CONCLUSIONS

Repeat rebiopsy can increase the T790M mutation positivity rate. Osimertinib showed similar efficacy and safety in T790M-positive patients whether detected by the first or repeat rebiopsy.

Diagnostic value of programmed cell death-ligand 1 expression on circulating tumor cells in lung cancer: A systematic review and meta-analysis

The expression of programmed cell death-ligand 1 (PD-L1) on circulating tumor cells offers a noninvasive method for the detection of PD-L1 expression in lung cancer, and could serve as a potential surrogate for cancer tissue. However, discrepant results make it difficult to apply PD-L1 on circulating tumor cells to clinical practice. Therefore, we conducted a meta-analysis to investigate the diagnostic value of PD-L1 on circulating tumor cells in lung cancer. To identify the relationship between the expression of PD-L1 on circulating tumor cells and lung cancer, the PubMed, Web of Science, Embase, China National Knowledge Infrastructure, and Wanfang databases were searched from inception to March 2023. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and the corresponding 95% confidence intervals were calculated to assess the diagnostic performance of PD-L1. We also conducted subgroup and sensitivity analyses. A total of 11 studies including 472 lung cancer patients were included in our study. The overall performance in terms of pooled sensitivity and specificity was 0.72 (0.52-0.86) and 0.54 (0.25-0.81), respectively. The positive likelihood ratio, negative likelihood ratio, and area under the curve were 1.57 (0.87-2.84), 0.52 (0.30-0.90), and 0.70 (0.66-0.74), respectively. Deeks' funnel plot test indicated no publication bias. Our analysis demonstrated that positive PD-L1 expression on circulating tumor cells (CTCs) exhibited a moderate diagnostic value in lung cancer, and CTCs may serve as a feasible alternative tissue analysis for the detection of PD-L1 in lung cancer.

Understanding the feasibility of chemotherapeutic and immunotherapeutic targets against non-small cell lung cancers: an update of resistant responses and recent combinatorial therapies

Despite consistent progress in prompt diagnosis and curative therapies in the last decade, lung cancer (LC) continues to threaten mankind, accounting for nearly twice the casualties compared to prostate, breast, and other cancers. Statistics associate ~25% of 2021 cancer-related deaths with LC, more than 80% of which are explicitly caused by tobacco smoking. Prevailing as small and non-small cell pathologies, with respective occurring frequency of nearly 15% and 80-85%, non-small cell LCs (NSCLCs) are prominently distinguished into lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC), subtypes. Since the first use of epidermal growth factor receptor (EGFR) inhibitor gefitinib for NSCLC treatment in 2002, immense progress has been made for targeted therapies with the next generation of drugs spanning across the chronological generations of small molecule inhibitors. The last two years have overseen the clinical approval of more than 10 therapeutic agents as first-line NSCLC medications. However, uncertain mutational aberrations as well as systemic resistant responses, and abysmal overall survival curtail the combating efficacies. Of late, immune checkpoint inhibitors (ICIs) against various molecules including programmed cell death-1 (PD-1) and its ligand (PD-L1) have been demonstrated as reliable LC treatment targets. Keeping these aspects in mind, this review article discusses the success of NSCLC chemo and immunotherapies with their characteristic effectiveness and future perspectives.

Neoadjuvant therapy in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) stages I-III were previously predominantly treated with surgery and chemotherapy. With the advent of Checkmate-816, neoadjuvant nivolumab and chemotherapy was FDA approved for the treatment of resectable NSCLC. There are several ongoing trials evaluating other neoadjuvant combinations of chemotherapy and immunotherapy as well as targeted therapies towards driver mutations. Here, we review previous clinical trials and discuss current ongoing trials' potential benefits and challenges.

Efficacy and safety of adjuvant EGFR TKI alone and in combination with chemotherapy for resected EGFR mutation-positive non-small cell lung cancer: A Bayesian network meta-analysis

Adjuvant therapy with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), alone or with chemotherapy, is used for early-stage non-small cell lung cancer (NSCLC) with EGFR mutations. A Bayesian meta-analysis was conducted to compare the efficacy and safety of adjuvant EGFR-TKI and adjuvant chemotherapy plus EGFR-TKI to determine whether additional adjuvant chemotherapy is beneficial. Randomised controlled trials and retrospective comparative studies examining the efficacy of adjuvant EGFR-TKI were searched from inception to July 2022. Ten studies (1344 patients) were analysed. Disease-free survival (DFS), overall survival (OS), and adverse events (AEs) were the endpoints. Our network meta-analysis demonstrated that EGFR-TKI monotherapy is noninferior to chemotherapy plus EGFR-TKI for DFS and OS in the adjuvant setting. However, combination treatment was associated with a higher AE incidence and severity. Adjuvant EGFR-TKI monotherapy seems a viable alternative to chemotherapy plus EGFR-TKI in patients with resected EGFR mutation-positive NSCLC.

The Resistance to EGFR-TKIs in Non-Small Cell Lung Cancer: From Molecular Mechanisms to Clinical Application of New Therapeutic Strategies

Almost 17% of Western patients affected by non-small cell lung cancer (NSCLC) have an activating epidermal growth factor receptor (EGFR) gene mutation. Del19 and L858R are the most-common ones; they are positive predictive factors for EGFR tyrosine kinase inhibitors (TKIs). Currently, osimertinib, a third-generation TKI, is the standard first-line therapy for advanced NSCLC patients with common EGFR mutations. This drug is also administered as a second-line treatment for those patients with the T790M EGFR mutation and previously treated with first- (erlotinib, gefitinib) or second- (afatinib) generation TKIs. However, despite the high clinical efficacy, the prognosis remains severe due to intrinsic or acquired resistance to EGRF-TKIs. Various mechanisms of resistance have been reported including the activation of other signalling pathways, the development of secondary mutations, the alteration of the downstream pathways, and phenotypic transformation. However, further data are needed to achieve the goal of overcoming resistance to EGFR-TKIs, hence the necessity of discovering novel genetic targets and developing new-generation drugs. This review aimed to deepen the knowledge of intrinsic and acquired molecular mechanisms of resistance to EGFR-TKIs and the development of new therapeutic strategies to overcome TKIs' resistance.

Challenges of EGFR-TKIs in NSCLC and the potential role of herbs and active compounds: From mechanism to clinical practice

Epidermal growth factor receptor (EGFR) mutations are the most common oncogenic driver in non-small cell lung cancer (NSCLC). Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are widely used in the treatment of lung cancer, especially in the first-line treatment of advanced NSCLC, and EGFR-TKIs monotherapy has achieved better efficacy and tolerability compared with standard chemotherapy. However, acquired resistance to EGFR-TKIs and associated adverse events pose a significant obstacle to targeted lung cancer therapy. Therefore, there is an urgent need to seek effective interventions to overcome these limitations. Natural medicines have shown potential therapeutic advantages in reversing acquired resistance to EGFR-TKIs and reducing adverse events, bringing new options and directions for EGFR-TKIs combination therapy. In this paper, we systematically demonstrated the resistance mechanism of EGFR-TKIs, the clinical strategy of each generation of EGFR-TKIs in the synergistic treatment of NSCLC, the treatment-related adverse events of EGFR-TKIs, and the potential role of traditional Chinese medicine in overcoming the resistance and adverse reactions of EGFR-TKIs. Herbs and active compounds have the potential to act synergistically through multiple pathways and multiple mechanisms of overall regulation, combined with targeted therapy, and are expected to be an innovative model for NSCLC treatment.

Phase 2 Study of Osimertinib in Combination with Platinum and Pemetrexed in Patients with Previously Untreated EGFR-Mutated Advanced Non-Squamous Non-Small Cell Lung Cancer: The OPAL Study

BACKGROUND

This multicenter phase 2 trial evaluated the safety and efficacy of osimertinib and platinum-based chemotherapy (OPP) in patients with previously untreated EGFR-mutated advanced non-squamous non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

Patients received osimertinib 80 mg once daily (QD), with either cisplatin 75 mg/m² (arm A) or carboplatin (area under the curve [AUC] = 5; arm B), plus pemetrexed 500 mg/m² for four cycles and maintenance therapy of osimertinib 80 mg QD with pemetrexed 500 mg/m² every 3 weeks. The primary end-points were safety and objective response rate (ORR), and the secondary end-points were complete response rate (CRR), disease control rate (DCR), and progression-free survival (PFS).

RESULTS

In total, 67 patients (34 in arm A and 33 in arm B) were enrolled between July 2019 and February 2020. At the data cutoff (28th February 2022), 35 (52.2%) patients had discontinued the protocol treatment, including 10 (14.9%) due to adverse events. No treatment-related deaths occurred. In the full analysis set, the ORR, CRR, and DCR were 90.9% (95% confidence interval [CI], 84.0-97.8), 3.0% (0.0-7.2), and 97.0% (92.8-100.0), respectively. Based on updated survival data (data cutoff on August 31, 2022, median follow-up time: 33.4 months), the median PFS was 31.0 months (95% CI, 26.8 months-not reached) and median overall survival was not reached.

CONCLUSIONS

This is the first study to show that OPP has excellent efficacy with acceptable toxicity in previously untreated EGFR-mutated advanced non-squamous NSCLC patients.

Aumolertinib effectively reduces clinical symptoms of an EGFR L858R-mutant non-small cell lung cancer case coupled with osimertinib-induced severe thrombocytopenia: a case report

Replacement of first-generation or second-generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) with third-generation EGFR-TKIs remains the current standard of care for T790M mutations in patients with non-small cell lung cancer. Osimertinib is one of the first third-generation EGFR-TKIs to be approved and is also the most widely studied in clinical research. There has been widespread concern about the adverse effects of osimertinib such as cardiotoxicity and interstitial lung disease, but few articles have reported severe thrombocytopenia after osimertinib treatment. This article reports a 64-year-old woman with non-small cell lung cancer initially diagnosed with cT2aN1M1a, EGFR p.L858R, who developed disease progression and T790M after 32 months of first-line treatment with gefitinib (250 mg/day) before switching to second-line treatment with osimertinib (80 mg/day). Severe thrombocytopenia and active bleeding occurred after treatment with osimertinib, which improved with recombinant human thrombopoietin and platelet transfusion. Treatment was replaced with aumolertinib (110 mg/day). After platelet stabilization with aumolertinib treatment in combination with chest radiotherapy, this patient had progression-free survival for 9 months and overall survival for over 45 months. In conclusion, from our experience, aumolertinib has good efficacy and mild adverse effects, and is a good choice for non-small cell lung cancer patients with T790M, especially for patients at high risk of thrombocytopenia.

Therapeutic strategies for EGFR-mutated non-small cell lung cancer patients with osimertinib resistance

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are the preferential options for advanced non-small cell lung cancer (NSCLC) patients harboring EGFR mutations. Osimertinib is a potent irreversible third-generation EGFR-TKI targeting EGFR mutations but has little effect on wild-type EGFR. In view of its remarkable efficacy and manageable safety, osimertinib was recommended as the standard first-line treatment for advanced or metastatic NSCLC patients with EGFR mutations. However, as the other EGFR-TKIs, osimertinib will inevitably develop acquired resistance, which limits its efficacy on the treatment of EGFR-mutated NSCLC patients. The etiology of triggering osimertinib resistance is complex including EGFR-dependent and EGFR-independent pathways, and different therapeutic strategies for the NSCLC patients with osimertinib resistance have been developed. Herein, we comprehensively summarized the resistance mechanisms of osimertinib and discuss in detail the potential therapeutic strategies for EGFR-mutated NSCLC patients suffering osimertinib resistance for the sake of the improvement of survival and further achievement of precise medicine.

Randomised controlled trial of first-line tyrosine-kinase inhibitor (TKI) versus intercalated TKI with chemotherapy for EGFR-mutated nonsmall cell lung cancer

Introduction

Previous studies have shown interference between epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors and chemotherapy in the cell cycle, thus reducing efficacy. In this randomised controlled trial we investigated whether intercalated erlotinib with chemotherapy was superior compared to erlotinib alone in untreated advanced EGFR-mutated nonsmall cell lung cancer (NSCLC).

Materials and methods

Treatment-naïve patients with an activating EGFR mutation, ECOG performance score of 0-3 and adequate organ function were randomly assigned 1:1 to either four cycles of cisplatin-pemetrexed with intercalated erlotinib (day 2-16 out of 21 days per cycle) followed by pemetrexed and erlotinib maintenance (CPE) or erlotinib monotherapy. The primary end-point was progression-free survival (PFS). Secondary end-points were overall survival, objective response rate (ORR) and toxicity.

Results

Between April 2014 and September 2016, 22 patients were randomised equally into both arms; the study was stopped due to slow accrual. Median follow-up was 64 months. Median PFS was 13.7 months (95% CI 5.2-18.8) for CPE and 10.3 months (95% CI 7.1-15.5; hazard ratio (HR) 0.62, 95% CI 0.25-1.57) for erlotinib monotherapy; when compensating for number of days receiving erlotinib, PFS of the CPE arm was superior (HR 0.24, 95% CI 0.07-0.83; p=0.02). ORR was 64% for CPE versus 55% for erlotinib monotherapy. Median overall survival was 31.7 months (95% CI 21.8-61.9 months) for CPE compared to 17.2 months (95% CI 11.5-45.5 months) for erlotinib monotherapy (HR 0.58, 95% CI 0.22-1.41 months). Patients treated with CPE had higher rates of treatment-related fatigue, anorexia, weight loss and renal toxicity.

Conclusion

Intercalating erlotinib with cisplatin-pemetrexed provides a longer PFS compared to erlotinib alone in EGFR-mutated NSCLC at the expense of more toxicity.

Minimal residual disease in EGFR-mutant non-small-cell lung cancer

Targeted therapy with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) is an effective treatment for EGFR-mutant non-small-cell lung cancer (NSCLC), however most patients invariably relapse after a period of minimal residual disease (MRD). This mini-review explores the mechanistic pathways leading to tumour dormancy, cellular senescence and epigenetic changes involving YAP/TEAD activation. We describe the various approaches of utilising TKIs in combination with agents to intensify initial depth of response, enhance apoptosis and target senescence-like dormancy. This mini-review will also highlight the potential novel therapies under development targeting MRD to improve outcomes for patients with EGFR-mutant NSCLC.

The exploration of three different treatment models of osimertinib plus antiangiogenic agents in non‐small cell lung cancer: A real‐world study

Background

Real‐world application of osimertinib with antiangiogenic agents in non‐small cell lung cancer (NSCLC) is common, but the efficacy data are rarely reported.

Methods

To obtain an objective efficacy report of different real‐world treatment models of osimertinib and antiangiogenic agents.

Results

A total of 54 patients with NSCLC were enrolled into the study. Twelve (22.2%) who received a combination of antiangiogenic agents, when there was a trend of osimertinib resistance but did not reach imageology progressive disease (PD), were assigned to Group A, with a median overall survival (OS) and progression‐free survival (PFS) of 48.0 (95% CI, not reached) and 21.0 (95% CI: 16.7–25.3) months, respectively. Thirty (55.6%) who received a combination of antiangiogenic agents when there was imageology PD during treatment with osimertinib were assigned to Group B, with a median OS and PFS of 31.8 (95% CI: 26.6–37.1) and 9.2 (95% CI: 5.9–12.6) months, respectively. Twelve (22.2%) who received a combination of antiangiogenic agents at the initial treatment with osimertinib were assigned to Group C, with a median OS and PFS of 28.5 (95% CI: 15.2–41.8) and 15.3 (95% CI: 7.9–22.7) months, respectively. Patients in Group A achieved a significant prolonged median PFS (p < 0.001) compared with Groups B and C. Absence of epidermal growth factor receptor (EGFR) T790M mutations (p = 0.043; hazard ratio [HR] = 2.124, 95% CI: 1.023–4.413) and no previous antiangiogenic agent application (p = 0.012; HR = 0.362, 95% CI: 0.163–0.863) were the independent prognostic factors of OS.

Conclusion

The well‐timed action to combine antiangiogenic agents was when there was a trend of osimertinib resistance. The absence of EGFR T790M mutations and previous use of antiangiogenic agents were poor prognostic factors.

An updated network meta-analysis of EGFR-TKIs and combination therapy in the first-line treatment of advanced EGFR mutation positive non-small cell lung cancer

Objectives

Tyrosine kinase inhibitors (TKIs) are a standard care option in patients with non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutation. TKI-based combination treatment modes show encouraging outcomes. However, it remains unknown which is the optimal treatment as the first-line regimen for these patients on overall survival (OS).

Materials and methods

Randomized controlled trials and meeting abstracts that investigated EGFR-TKIs alone or in combination as front-line care for patients with NSCLC were systematically searched in relevant databases and reviewed. Fixed and random effects network meta-analysis models were used to estimate progression-free survival (PFS), OS, overall response rate, and grade three and higher adverse events (AEs). Surface under the cumulative ranking curves (SUCRAs) were used to rank treatment effects.

Results

Eighteen studies covering six treatments and involving a total of 4389 patients were included in this network meta-analysis. On OS, the top three treatment were first-generation EGFR-TKIs (1G EGFR-TKIs) plus chemotherapy (SUCRA, 88.1%), osimertinib (SUCRA, 65.8%) and second-generation EGFR-TKIs (2GEGFR-TKIs) (SUCRA, 63.3%). On PFS, the top three treatments were osimertinib (SUCRA, 96.0%), 1G EGFR-TKIs plus chemotherapy (SUCRA, 67.1%), and 1G EGFR-TKIs plus antiangiogenesis (SUCRA, 48.2%). Two types of TKI-based combination therapy have significantly higher risk of grade three and higher AEs than TKI alone.

Conclusion

1G EGFR-TKIs plus chemotherapy and osimertinib seem to be the two better options as first-line care in advanced NSCLC patients with EGFR-mutation. Osimertinib caused the lowest incidence of AEs. However, TKIs-based combination therapy significantly increased AEs.

Sequence-dependent synergistic effect of aumolertinib-pemetrexed combined therapy on EGFR-mutant non-small-cell lung carcinoma with pre-clinical and clinical evidence

BACKGROUND

Inevitably developed resistance of the third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) limited its clinical benefit on non-small cell lung cancer (NSCLC). Upfront combination therapy is promising to prevent this resistance. Compelling clinical evidence indicated the failure of third-generation EGFR TKIs combined with either immunotherapy or antiangiogenic agents. In comparison, combined treatment of third-generation EGFR TKIs and chemotherapy might be a favorable choice. Herein, we systematically analyzed and compared the effects of pemetrexed and a novel third-generation EGFR TKI aumolertinib combined in different sequences, subsequently revealed the potential mechanisms and proved the optimal combination schedule with clinical retrospective study.

METHODS

Three combination schedules involving pemetrexed and aumolertinib in different sequences were developed. Their inhibition effects on cell proliferation and metastasis were firstly compared upon three human NSCLC cell lines in vitro, by cell counting kit-8, colony formation, wound healing and transwell assays respectively. Further evaluation in vivo was proceeded upon H1975 and HCC827 xenograft model. Gene and protein expression were detected by Q-PCR and western blot. Drug concentration was determined by LC-MS/MS. VEGF secretion was determined by ELISA. Tumor vessel was visualized by immunofluorescence. Lastly, a clinical retrospective study was raised with 65 patients' data.

RESULTS

The combination of pemetrexed and aumolertinib exhibited a sequence-dependent and EGFR mutant-dependent synergistic effect in vitro and in vivo. Only treatment with aumolertinib following pemetrexed (P-A) exhibited synergistic effect with stronger anti-tumor growth and anti-metastasis ability than monotherapy and also other combination sequences. This synergism could exclusively be observed in H1975 and HCC827 but not A549. Pathway analysis showed that P-A significantly enhanced the suppression of EGFR pathway. In addition, our results intriguingly found an obvious reduction of VEGF secretion and the accompanying normalization of the intratumor vessel, consequently increasing intratumoral accumulation of pemetrexed in P-A group. Finally, the clinical retrospective study verified the synergistic effect of P-A combination by significantly superior tumor response than aumolertinib monotherapy.

CONCLUSION

Aumolertinib-pemetrexed combined therapy is promising for EGFR mutant NSCLC but only in right administration sequence. P-A could become an advantageous combination strategy in clinical with synergistic inhibition of tumor growth and metastasis.

Osimertinib and chemotherapy combination to treat brain metastasis flare and osimertinib resistance by EGFR C797S

Chemotherapy or involvement in a clinical trial remain the standard treatment for patients with EGFR mutant non-small cell lung cancer who have disease progression while receiving Osimertinib. Rapid progression, also known as flare-phenomenon, has been described after discontinuation of tyrosine kinase inhibitors. In this case, we describe a young woman who has extracranial progressive disease due to EGFR C797S resistance mutation while being treated with osimertinib, with a rapid neurological deterioration after osimertinib withdrawal due to flare-phenomenon progression in the brain, and a prompt intracranial response with osimertinib reintroduction in addition to chemotherapy to achieve extracranial diseases control.

Epidermal growth factor receptor-targeted therapy for the treatment of non-small cell lung cancer: A review of phase II and III trials

INTRODUCTION

EGFR is one of the most common driver gene mutations in lung cancer. EGFR-TKI monotherapy and EGFR-TKI combined with chemotherapy or anti-angiogenesis drugs have significantly prolonged the survival of patients with EGFR-mutant NSCLC. However, disease progression caused by acquired resistance to EGFR-TKIs is inevitable. And patients with EGFR exon 20ins showed limited efficacy to EGFR-TKIs.

AREAS COVERED

In this review, we initially evaluated the efficacy of existing treatments for EGFR-mutant NSCLC. Second, we reviewed the ongoing phase II and III clinical trials, provide the latest results, discuss the scientific rationale of these trials and the potential development issues.

EXPERT OPINION

The application of EGFR-TKIs has greatly changed the therapeutic strategies for advanced and resected NSCLC with EGFR mutations, and the 5-year OS rate for advanced NSCLC was close to 40%. The current research direction for the treatment of patients with EGFR mutations focuses on the following three aspects: uncommon EGFR mutation subtypes NSCLC, brain metastases, and EGFR TKI-based combination therapy. Future studies on EGFR-mutant NSCLC therapy will focus on overcoming EGFR-TKI-related resistance, preventing drug resistance in advance, and developing bispecific antibody drugs. ADCs may be the promising strategy for patients with acquired resistance to EGFR-TKIs.

The Influence of CYP3A4 Genetic Polymorphism and Proton Pump Inhibitors on Osimertinib Metabolism

The aim of this study was to 1) investigate the effects of 27 CYP3A4 variants on the metabolism of osimertinib and 2) study the interactions between osimertinib and others as well as the underlying mechanism. A recombinant human CYP3A4 enzymatic incubation system was developed and employed to determine the kinetic profile of CYP3A4 variants. Ultra-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS) was applied to detect the concentration of the main metabolite, AZ5104. The results demonstrated that the relative clearance rates of CYP3A4.19, 10, 18, 5, 16, 14, 11, 2, 13, 12, 7, 8, and 17 in catalyzing osimertinib were significantly reduced to a minimum of 25.68% compared to CYP3A4.1, while those of CYP3A4.29, 32, 33, 28, 15, 34, and 3 were obviously enhanced, ranging from 114.14% to 284.52%. The activities of the remaining variants were almost equal to those of CYP3A4.1. In addition, 114 drugs were screened to determine the potential interaction with osimertinib based on the rat liver microsome (RLM) reaction system. Sixteen of them inhibited the production of AZ5104 to 20% or less, especially proton pump inhibitors, among which the IC₅₀ of rabeprazole was 6.49 ± 1.17 μM in RLM and 20.39 ± 2.32 μM in human liver microsome (HLM), with both following competitive and non-competitive mixed mechanism. In an in vivo study, Sprague–Dawley (SD) rats were randomly divided into groups, with six animals per group, receiving osimertinib with or without rabeprazole, omeprazole, and lansoprazole. We found that the AUC_(0–t), AUC_(0–∞), and C_max of osimertinib decreased significantly after co-administration with rabeprazole orally, but they increased remarkably when osimertinib was administered through intraperitoneal injection. Taken together, our data demonstrate that the genetic polymorphism and proton pump inhibitors remarkably influence the disposition of osimertinib, thereby providing basic data for the precise application of osimertinib.

Osimertinib Rechallenge With Bevacizumab vs. Chemotherapy Plus Bevacizumab in EGFR-Mutant NSCLC Patients With Osimertinib Resistance

At present, treatment options for osimertinib resistance are very limited. Dual inhibition of the vascular endothelial growth factor (VEGF) and epidermal growth factor receptor (EGFR) significantly improved the progression-free survival (PFS) of advanced EGFR-mutant non–small cell lung cancer (NSCLC). After EGFR-tyrosine kinase inhibitor (TKI) resistance, EGFR-TKI continuation combined with VEGF inhibitors still had clinical benefits. It is unclear whether the addition of bevacizumab after osimertinib progresses will prolong the duration of the osimertinib benefit. We screened 1289 patients with NSCLC and finally included 96 patients to evaluate osimertinib combined with bevacizumab (osi + bev) versus chemotherapy combined with bevacizumab (che + bev) for patients with acquired resistance to osimertinib. The overall response rate (ORR) for osi + bev and chem + bev was 15.8% (6 of 38) and 20.7% (12 of 58), respectively. The median PFS for osi + bev and che + bev was 7.0 and 4.9 months (HR 0.415 95%CI: 0.252–0.687 p = 0.001). The median OS for osi + bev and che + bev was 12.6 and 7.1 months (HR 0.430 95%CI: 0.266–0.696 p = 0.001). Multivariate analyses showed that no brain metastases and osi + bev treatment after osimertinib resistance correlated with longer PFS (p = 0.044, p = 0.001), while the median PFS of osimertinib less than 6 months (p = 0.021) had a detrimental effect on sequent treatment. Only osi + bev treatment was identified as an independent predictor of OS (p = 0.001). The most common adverse events (AEs) of grade ≥3 were hypertension (13.2%) and diarrhea (10.5%) in the osi + bevacizumab group. Neutropenia (24.1%) and thrombocytopenia (19%) were the most common grade ≥3 AEs in the che + bev group. The overall incidence of serious AEs (grade ≥3) was significantly higher in the chemotherapy plus bevacizumab group. Our study has shown the superiority of osi + bev compared to che + bev after the failure of osimertinib, making it a preferred option for patients with acquired resistance to osimertinib.

Hype or hope - Can combination therapies with third-generation EGFR-TKIs help overcome acquired resistance and improve outcomes in EGFR-mutant advanced/metastatic NSCLC?

Three generations of epidermal growth factor receptor - tyrosine kinase inhibitors (EGFR-TKIs) have been developed for treating advanced/metastatic non-small cell lung cancer (NSCLC) patients harboring EGFR-activating mutations, while a fourth generation is undergoing preclinical assessment. Although initially effective, acquired resistance to EGFR-TKIs usually arises within a year due to the emergence of clones harboring multiple resistance mechanisms. Therefore, the combination of EGFR-TKIs with other therapeutic agents has emerged as a potential strategy to overcome resistance and improve clinical outcomes. However, results obtained so far are ambiguous and ideal therapies for patients who experience disease progression during treatment with EGFR-TKIs remain elusive. This review provides an updated landscape of EGFR-TKIs, along with a description of the mechanisms causing resistance to these drugs. Moreover, it discusses the current knowledge, limitations, and future perspective regarding the use of EGFR-TKIs in combination with other anticancer agents, supporting the need for bench-to-bedside approaches in selected populations.