Central nervous system metastases and oligoprogression during treatment with tyrosine kinase inhibitors in oncogene-addicted non-small cell lung cancer: how to treat and when?

Establishment and Characterization of a Brain Parenchymal Metastatic Cell Line AlmoR1 Derived From an NSCLC Patient With EGFR-TKI Resistance

BACKGROUND

Non-small cell lung cancer patients with EGFR mutation have a high rate of brain metastases, and EGFR tyrosine kinase inhibitors (TKIs) are the principal therapeutic approach. However, acquired targeted therapy resistance is the main reason for EGFR-TKIs' treatment failure. At present, the mechanism of intracranial acquired targeted therapy resistance is limited, mainly due to the lack of a cell line that can be used for its study.

METHODS

A brain parenchymal metastatic sample that progressed after third-generation EGFR-TKI treatment was used to establish a cell line named AlmoR1. The genetic characteristics of the cell line were evaluated by short tandem repeat (STR) profiling and whole-exome sequencing analysis. The phenotypic characteristics were characterized by CCK8, western blot, HE staining, immunohistochemistry (IHC), and orthotopic brain tumor model.

RESULTS

The cell line we successfully established, AlmoR1, can be passed in vitro stably. STR analysis revealed it was a novel NSCLC BM cell line. It harbors the EGFR E746_A750del (ex19del) mutation, and the IC50 to almonertinib and osimertinib of AlmoR1 was significantly higher than that of sensitive cells. In our orthotopic brain tumor model construction with AlmoR1 cells, 75% (3/4) tumor formation can be observed in the living system.

CONCLUSIONS

These data suggest that the established cell line, AlmoR1, preserved the resistance to broad third-generation EGFR-TKIs and good tumorigenicity in an intracranial orthotopic model, so that it can serve as a new tool to elucidate the pathogenesis, explore new treatment methods, and conduct the development of new drugs for targeted therapy resistance of brain metastases.

Efficacy of ramucirumab combined with erlotinib or osimertinib in untreated EGFR-mutated NSCLC patients with asymptomatic brain metastases: insights from molecular biomarkers in the RELAY-brain trial

BACKGROUND

The RELAY-Brain trial examined the clinical utility and survival impacts of ramucirumab (RAM) combined with epidermal growth factor receptor (EGFR)-TKI in patients with EGFR-mutated non-small-cell lung cancer (NSCLC) with brain metastases. Although RAM combined with erlotinib (ERL) is known to have clinical benefits, the benefits in patients with baseline brain metastases remain unclear. This report examined the long-term follow-up data (Japan Registry of Clinical Trials: jRCTs2051190027) of the same patients, analyzing relevant biomarkers from tumor and plasma samples.

PATIENTS AND METHODS

The six patients enrolled in the RELAY-Brain trial received RAM plus ERL or osimertinib (OSM). Our long-term follow-up observational study assessed patient survival, treatment status, and genetic biomarkers. Tumor and plasma samples were analyzed at baseline, during treatment, and at disease progression using next-generation sequencing and droplet digital PCR, to identify gene alterations and EGFR-TKI-resistant mutations.

RESULTS

After median follow-up of 44.2 months, the first site of disease progression in three of the patients was the brain metastases. In the RAM + ERL group, two patients with the T790M mutation subsequently received OSM. Progression-free survival (PFS) and overall survival ranged from 10.46 to 42.07 months and from 30.14 to 52.25 months, respectively. Gene alterations included TP53 mutations in three patients and ERBB2 and PIK3CA mutations in two. TP53 mutations were associated with shorter PFS.

CONCLUSION

RAM with ERL or OSM achieved significant clinical benefits for patients with EGFR-mutated NSCLC with asymptomatic brain metastases. These positive outcomes and the identification of related biomarkers support the therapeutic potential of these combinations.

CNS Efficacy of Osimertinib With or Without Chemotherapy in Epidermal Growth Factor Receptor-Mutated Advanced Non-Small-Cell Lung Cancer

PURPOSE

We report CNS efficacy of first-line osimertinib plus chemotherapy versus osimertinib monotherapy in patients with epidermal growth factor receptor (EGFR)-mutated advanced non-small-cell lung cancer (NSCLC) from the phase III FLAURA2 study according to baseline CNS metastasis status.

METHODS

Patients were randomly assigned to osimertinib plus platinum-pemetrexed (combination) or osimertinib monotherapy until disease progression or discontinuation. Brain scans were performed in all patients at baseline and progression and at scheduled assessments until progression for patients with baseline CNS metastases; scans were assessed by neuroradiologist CNS blinded independent central review (BICR).

RESULTS

On the basis of baseline CNS BICR, 118 of 279 (combination) and 104 of 278 (monotherapy) randomly assigned patients had ≥one measurable and/or nonmeasurable CNS lesion and were included in the CNS full analysis set (cFAS); 40 of 118 and 38 of 104 had ≥one measurable target CNS lesion and were included in the post hoc CNS evaluable-for-response set (cEFR). In the cFAS, the hazard ratio (HR) for CNS progression or death was 0.58 (95% CI, 0.33 to 1.01). In patients without baseline CNS metastases, the HR for CNS progression or death was 0.67 (95% CI, 0.43 to 1.04). In the cFAS, CNS objective response rates (ORRs; 95% CI) were 73% (combination; 64 to 81) versus 69% (monotherapy; 59 to 78); 59% versus 43% had CNS complete response (CR). In the cEFR, CNS ORRs (95% CI) were 88% (73 to 96) versus 87% (72 to 96); 48% versus 16% had CNS CR.

CONCLUSION

Osimertinib plus platinum-pemetrexed demonstrated improved CNS efficacy compared with osimertinib monotherapy, including delaying CNS progression, irrespective of baseline CNS metastasis status. These data support this combination as a new first-line treatment for patients with EGFR-mutated advanced NSCLC, including those with CNS metastases.

Computational markers for personalized prediction of outcomes in non-small cell lung cancer patients with brain metastases

Intracranial progression after curative treatment of early-stage non-small cell lung cancer (NSCLC) occurs from 10 to 50% and is difficult to manage, given the heterogeneity of clinical presentations and the variability of treatments available. The objective of this study was to develop a mechanistic model of intracranial progression to predict survival following a first brain metastasis (BM) event occurring at a time [Formula: see text]. Data included early-stage NSCLC patients treated with a curative intent who had a BM as the first and single relapse site (N = 31). We propose a mechanistic mathematical model able to derive computational markers from primary tumor and BM data at [Formula: see text] and estimate the amount and sizes of (visible and invisible) BMs, as well as their future behavior. These two key computational markers are [Formula: see text], the proliferation rate of a single tumor cell; and [Formula: see text], the per day, per cell, probability to metastasize. The predictive value of these individual computational biomarkers was evaluated. The model was able to correctly describe the number and size of metastases at [Formula: see text] for 20 patients. Parameters [Formula: see text] and [Formula: see text] were significantly associated with overall survival (OS) (HR 1.65 (1.07-2.53) p = 0.0029 and HR 1.95 (1.31-2.91) p = 0.0109, respectively). Adding the computational markers to the clinical ones significantly improved the predictive value of OS (c-index increased from 0.585 (95% CI 0.569-0.602) to 0.713 (95% CI 0.700-0.726), p < 0.0001). We demonstrated that our model was applicable to brain oligoprogressive patients in NSCLC and that the resulting computational markers had predictive potential. This may help lung cancer physicians to guide and personalize the management of NSCLC patients with intracranial oligoprogression.

Outcomes of surgery and subsequent therapy for central nervous system oligoprogression in EGFR-mutated NSCLC patients

BACKGROUND

Oligoprogression is an emerging issue in patients with epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC). However, the surgical treatment for central nervous system (CNS) oligoprogression is not widely discussed. We investigated the outcomes of craniotomy with adjuvant whole-brain radiotherapy (WBRT) and subsequent therapies for CNS oligoprogression in patients with EGFR-mutated NSCLC.

METHODS

NSCLC patients with CNS oligoprogression were identified from a tertiary medical center. The outcomes of surgery with adjuvant WBRT or WBRT alone were analyzed, along with other variables. Overall survival and progression-free survival were analyzed using the log-rank test as the primary and secondary endpoints. A COX regression model was used to identify the possible prognostic factors.

RESULTS

Thirty-seven patients with CNS oligoprogression who underwent surgery or WBRT were included in the study after reviewing 728 patients. Twenty-one patients underwent surgery with adjuvant WBRT, and 16 received WBRT alone. The median overall survival for surgery and WBRT alone groups was 43 (95% CI 17-69) and 22 (95% CI 15-29) months, respectively. Female sex was a positive prognostic factor for overall survival (OR 0.19, 95% CI 0.06-0.57). Patients who continued previous tyrosine kinase inhibitors (OR 3.48, 95% CI 1.06-11.4) and induced oligoprogression (OR 3.35, 95% CI 1.18-9.52) were associated with worse overall survival. Smoking history (OR 4.27, 95% CI 1.54-11.8) and induced oligoprogression (OR 5.53, 95% CI 2.1-14.7) were associated with worse progression-free survival.

CONCLUSIONS

Surgery combined with adjuvant WBRT is a feasible treatment modality for CNS oligoprogression in patients with EGFR-mutated NSCLC. Changing the systemic-targeted therapy after local treatments may be associated with improved overall survival.

Modern Stereotactic Radiotherapy for Brain Metastases from Lung Cancer: Current Trends and Future Perspectives Based on Integrated Translational Approaches

Brain metastases (BMs) represent the most frequent metastatic event in the course of lung cancer patients, occurring in approximately 50% of patients with non-small-cell lung cancer (NSCLC) and in up to 70% in patients with small-cell lung cancer (SCLC). Thus far, many advances have been made in the diagnostic and therapeutic procedures, allowing improvements in the prognosis of these patients. The modern approach relies on the integration of several factors, such as accurate histological and molecular profiling, comprehensive assessment of clinical parameters and precise definition of the extent of intracranial and extracranial disease involvement. The combination of these factors is pivotal to guide the multidisciplinary discussion and to offer the most appropriate treatment to these patients based on a personalized approach. Focal radiotherapy (RT), in all its modalities (radiosurgery (SRS), fractionated stereotactic radiotherapy (SRT), adjuvant stereotactic radiotherapy (aSRT)), is the cornerstone of BM management, either alone or in combination with surgery and systemic therapies. We review the modern therapeutic strategies available to treat lung cancer patients with brain involvement. This includes an accurate review of the different technical solutions which can be exploited to provide a "state-of-art" focal RT and also a detailed description of the systemic agents available as effective alternatives to SRS/SRT when a targetable molecular driver is present. In addition to the validated treatment options, we also discuss the future perspective for focal RT, based on emerging clinical reports (e.g., SRS for patients with many BMs from NSCLC or SRS for BMs from SCLC), together with a presentation of innovative and promising findings in translational research and the combination of novel targeted agents with SRS/SRT.

Osimertinib for EGFR-Mutant Non-Small-Cell Lung Cancer Central Nervous System Metastases: Current Evidence and Future Perspectives on Therapeutic Strategies

Central nervous system (CNS) metastases are common in non-small-cell lung cancer (NSCLC) and associated with poor prognosis and high disease burden. Effective options are needed to treat CNS metastases, and delay or prevent their formation. For epidermal growth factor receptor mutation-positive (EGFRm) advanced NSCLC and brain metastases, upfront EGFR-tyrosine kinase inhibitors (TKIs) are recommended by the joint European Association of Neuro-Oncology-European Society for Medical Oncology and experts. While early-generation EGFR-TKIs have limited CNS efficacy, the third-generation, irreversible, EGFR-TKI osimertinib has potent efficacy in NSCLC CNS metastases. This review discusses the CNS data of osimertinib in the context of therapeutic strategies and future prospects based on expert review of published literature and relevant clinical, real-world, and ongoing studies in this setting. Osimertinib penetrates the blood-brain barrier and achieves greater exposure in the brain compared with other EGFR-TKIs. Osimertinib has demonstrated CNS efficacy, including in leptomeningeal metastases, in EGFRm advanced disease. In EGFRm stage IB-IIIA NSCLC, adjuvant osimertinib reduced CNS disease recurrence versus placebo. The burden and poor prognosis of CNS metastases necessitate more therapeutic options for their management and reduced risk of recurrence in patients with EGFRm NSCLC. Clinical studies are ongoing in advanced disease to investigate osimertinib combinations with chemotherapy/radiation therapy and optimal treatment post-CNS progression with osimertinib. Further prospective research evaluating treatments using CNS-specific endpoints and evaluating CNS resistance is needed to improve outcomes for patients with CNS metastases.

Screening for Brain Metastases in Patients With NSCLC: A Qualitative Study on the Psychologic Impact of Being Diagnosed With Asymptomatic Brain Metastases

Introduction

The brain is a frequent site of metastases in NSCLC, and screening for asymptomatic brain metastases (BM) is increasingly advised in NSCLC guidelines. An asymptomatic BM diagnosis may trigger anxiety for future neurologic problems and can negatively affect quality of life of patients and their relatives. Therefore, we performed this qualitative study.

Methods

Three focus group discussions were organized with patients with NSCLC and asymptomatic BM (N = 3–4 per group) and separately with their relatives, to explore this psychosocial impact. Two researchers independently performed an inductive content analysis.

Results

A total of 10 patients and 10 relatives participated in six focus groups. A diagnosis of BM caused feelings of distress and anxiety in both patients and relatives. These feelings diminished over time in case of a tumor responding to systemic therapy. The diagnosis of BM was not perceived as more distressful than other metastases, and scan-related anxiety was not experienced. Although magnetic resonance imaging screening and follow-up were thought of as burdensome, follow-up was valued. The coping strategies of both groups seemed related to personality and to the efficacy of the given systemic therapy. Relatives appreciated peer support of other relatives during the focus groups, and they seemed open for future psychological support.

Conclusions

Asymptomatic BM diagnosis can cause anxiety and distress, but this diminishes over time with effective systemic treatment. Although patients perceive magnetic resonance imaging as burdensome, they value follow-up screening and imaging. Relatives highly appreciated peer support, and psychological distress of relatives should not be overlooked.

Resistance to TKIs in EGFR-Mutated Non-Small Cell Lung Cancer: From Mechanisms to New Therapeutic Strategies

Resistance to tyrosine kinase inhibitors (TKIs) of the epidermal growth factor receptor (EGFR) in advanced mutant Non-Small Cell Lung Cancer (NSCLC) constitutes a therapeutic challenge. This review intends to summarize the existing knowledge about the mechanisms of resistance to TKIs in the context of EGFR mutant NSCLC and discuss its clinical and therapeutic implications. EGFR-dependent and independent molecular pathways have the potential to overcome or circumvent the activity of EGFR-targeted agents including the third-generation TKI, osimertinib, negatively impacting clinical outcomes. CNS metastases occur frequently in patients on EGFR-TKIs, due to the inability of first and second-generation agents to overcome both the BBB and the acquired resistance of cancer cells in the CNS. Newer-generation TKIs, TKIs targeting EGFR-independent resistance mechanisms, bispecific antibodies and antibody-drug conjugates or combinations of TKIs with other TKIs or chemotherapy, immunotherapy and Anti-Vascular Endothelial Growth Factors (anti-VEGFs) are currently in use or under investigation in EGFR mutant NSCLC. Liquid biopsies detecting mutant cell-free DNA (cfDNA) provide a window of opportunity to attack mutant clones before they become clinically apparent. Overall, EGFR TKIs-resistant NSCLC constitutes a multifaceted therapeutic challenge. Mapping its underlying mutational landscape, accelerating the detection of resistance mechanisms and diversifying treatment strategies are essential for the management of the disease.

ASCEND-7: Efficacy and Safety of Ceritinib Treatment in Patients with ALK-Positive Non-Small Cell Lung Cancer Metastatic to the Brain and/or Leptomeninges

PURPOSE

Central nervous system metastases are a prominent cause of morbidity and mortality in patients with ALK-positive (ALK+) non-small cell lung cancer (NSCLC). The phase II ASCEND-7 (NCT02336451) study was specifically designed to assess the efficacy and safety of the ALK inhibitor (ALKi) ceritinib in patients with ALK+ NSCLC metastatic to the brain and/or leptomeninges.

PATIENTS AND METHODS

Patients with active brain metastases were allocated to study arms 1 to 4 based on prior exposure to an ALKi and/or prior brain radiation (arm 1: prior radiotherapy/ALKi-pretreated; arm 2: no radiotherapy/ALKi-pretreated; arm 3: prior radiotherapy/ALKi-naïve; arm 4: no radiotherapy/ALKi-naïve). Arm 5 included patients with leptomeningeal carcinomatosis. Patients received ceritinib 750 mg once daily (fasted condition). Primary endpoint was investigator-assessed whole-body overall response rate (ORR) per RECIST v1.1. Secondary endpoints included disease control rate (DCR) and intracranial/extracranial responses.

RESULTS

Per investigator assessment, in arms 1 (n = 42), 2 (n = 40), 3 (n = 12), and 4 (n = 44), respectively: whole-body ORRs [95% confidence interval (CI)] were 35.7% (21.6-52.0), 30.0% (16.6-46.5), 50.0% (21.1-78.9), and 59.1% (43.2-73.7); whole-body DCR (95% CI): 66.7% (50.5-80.4), 82.5% (67.2-92.7), 66.7% (34.9-90.1), and 70.5% (54.8-83.2); intracranial ORRs (95% CI): 39.3% (21.5-59.4), 27.6% (12.7-47.2), 28.6% (3.7-71.0), and 51.5% (33.5-69.2). In arm 5 (n = 18), whole-body ORR was 16.7% (95% CI, 3.6-41.4) and DCR was 66.7% (95% CI, 41.0-86.7). Paired cerebrospinal fluid and plasma sampling revealed that ceritinib penetrated the human blood-brain barrier.

CONCLUSIONS

Ceritinib showed antitumor activity in patients with ALK+ NSCLC with active brain metastases and/or leptomeningeal disease, and could be considered in the management of intracranial disease. See related commentary by Murciano-Goroff et al., p. 2477.