Durable response to osimertinib in EGFR mutated T790M wildtype non-small cell lung cancer with leptomeningeal metastases: A case report

Brain metastasis: An insight into novel molecular targets for theranostic approaches

Brain metastases (BrM) are common malignant lesions in the central nervous system, and pose a significant threat in advanced-stage malignancies due to delayed diagnosis and limited therapeutic options. Their distinct genomic profiles underscore the need for molecular profiling to tailor effective treatments. Recent advances in cancer biology have uncovered molecular drivers underlying tumor initiation, progression, and metastasis. This, coupled with the advances in molecular imaging technology and radiotracer synthesis, has paved the way for the development of innovative radiopharmaceuticals with enhanced specificity and affinity for BrM specific targets. Despite the challenges posed by the blood-brain barrier to effective drug delivery, several radiolabeled compounds have shown promise in detecting and targeting BrM. This manuscript provides an overview of the recent advances in molecular biomarkers used in nuclear imaging and targeted radionuclide therapy in both clinical and preclinical settings. Additionally, it explores potential theranostic applications addressing the unique challenges posed by BrM.

Osimertinib is associated with improved outcomes in pre-treated non-small cell lung cancer leptomeningeal metastases: A systematic review and meta-analysiss

Purpose

Leptomeningeal metastasis (LM) is a severe complication of non-small cell lung cancer (NSCLC). In patients with NSCLC LM harboring epidermal growth factor receptor (EGFR) mutations, osimertinib is favored over alternative EGFR tyrosine kinase inhibitors (TKIs). However, the efficacy of osimertinib relative to other EGFR-TKIs is not well established for patients with LM. We aimed to compare the efficacy of EGFR-TKIs in EGFR-mutated NSCLC LM.

Methods

This systematic review and meta-analysis performed according to PRISMA guidelines included studies of adult patients with EGFR-mutated NSCLC and a diagnosis of LM who received an EGFR-TKI for the treatment of LM. We searched Medline ALL, Embase, Cochrane Central Register of Controlled Trials, Scopus, and Web of Science Core Collection. The evaluation of biases was done by using the Ottawa-Newscastle scale. The hazard ratio was used as the parameter of interest for overall survival (OS) and central nervous system-specific progression-free survival (PFS).

Results

128 publications were included with 243 patients and 282 lines of EGFR-TKI for NSCLC LM that met inclusion criteria. The median PFS in patients receiving any EGFR-TKI was 9.1 months, and the median OS was 14.5 months. In univariate analyses of the entire cohort, osimertinib treatment demonstrated significantly prolonged PFS, but not OS, compared to other EGFR-TKIs. Osimertinib demonstrated significantly prolonged PFS and OS in the subset of patients who were previously treated with EGFR-TKIs, but not in EGFR-TKI naïve patients.

Conclusion

Osimertinib is associated with improved outcomes compared to other EGFR-TKIs, particularly in patients previously treated with EGFR-TKIs. An important limitation is that most patients were derived from retrospective reports. These results highlight the need for prospective studies for this difficult-to-treat patient population.

Osimertinib for the treatment of epidermal growth factor receptor-mutated non-small cell lung cancer patients with leptomeningeal metastases and different T790M status

BACKGROUND

Leptomeningeal metastasis (LM) is a catastrophic complication for patients with non-small cell lung cancer (NSCLC) and carries an extremely poor prognosis. The efficacy of osimertinib 80 mg once daily for epidermal growth factor receptor-mutated (EGFRm) NSCLC with LM has yet to be fully assessed. This study aimed to investigate the efficacy of osimertinib in such patients and their genetic profiles at the time of LM diagnosis.

METHODS

From January 2016 to April 2020, pretreated EGFRm NSCLC patients who had progressed with cytologically confirmed symptomatic LM and received osimertinib 80 mg once daily were enrolled retrospectively. The objective response rate (ORR) and disease control rate (DCR) were evaluated, along with progression-free survival (PFS) and overall survival (OS). Next-generation sequencing of paired samples of cerebrospinal fluid and plasma collected at LM diagnosis was performed simultaneously.

RESULTS

Forty cases of EGFRm lung adenocarcinoma with LM were analyzed. Females accounted for 75.0% of enrollees. Of the patients, 37.5% had a poor Eastern Cooperative Oncology Group score (≥2). Twelve patients had received at least 2 prior lines of treatment. All patients received osimertinib treatment regardless of their T790M status. According to the Response Assessment in Neuro-Oncology (RANO)-LM criteria, the ORR and DCR were 20.0% and 95.0%, respectively. The median PFS and OS were 10.0 (95% CI: 7.7-12.3) and 15.1 months (95% CI: 11.0-19.4), respectively. No significant difference was observed between T790M-negative patients (n=24) and T790M-positive patients (n=16) with respect to PFS [median, 10.8 (95% CI: 7.7-13.8) vs. 8.8 months (95% CI: 7.3-10.3), HR=0.595, P=0.158] or OS [median, 17.2 (95% CI: 8.7-25.7) vs. 11.4 months (95% CI: 3.9-19.0), HR=0.913, P=0.822]. The detection rate of EGFR sensitizing mutations in cerebrospinal fluid was higher than that in plasma (97.5% vs. 50%, P=0.311), whereas the incidence of T790M detection in cerebrospinal fluid was significantly lower than that in plasma (20.0% vs. 32.5%, P=0.043).

CONCLUSIONS

Osimertinib 80 mg once daily shows good efficacy in pretreated EGFRm NSCLC patients with LM regardless of their T790M status. Combining cerebrospinal fluid and plasma testing can aid in revealing more genetic information.

First-line osimertinib for leptomeningeal metastasis from lung adenocarcinoma with EGFR mutation as the initial and solitary site of postoperative recurrence

Leptomeningeal metastasis (LM) from lung cancer has poor prognosis, and effective therapy has not been established. We present the case of a 54-year-old man with LM from lung adenocarcinoma harboring EGFR L858R point mutation, who received osimertinib as first-line therapy. He had previously undergone left lower lobectomy and lymph node dissection for lung adenocarcinoma. Five years and 9 months after the operation, he developed symptoms of dizziness, lightheadedness, and headache. Magnetic resonance imaging showed high signal intensity in the cerebral sulcus and meninges, and cerebrospinal fluid (CSF) cytology indicated adenocarcinoma with EGFR L858R point mutation, which suggested LM. After CSF drainage and administration of corticosteroid and glycerol, the patient received osimertinib (80 mg/day) as first-line therapy. These symptoms including dizziness, lightheadedness, and headache were relieved and the MRI appearance was normal, and he survived for 19 months with no disease progression. Osimertinib is considered to be an effective therapeutic option for LM from lung adenocarcinoma harboring EGFR mutation.

A PET study in healthy subjects of brain exposure of 11C-labelled osimertinib - A drug intended for treatment of brain metastases in non-small cell lung cancer

Osimertinib is a tyrosine kinase inhibitor (TKI) of the mutated epidermal growth factor receptor (EGFRm) with observed efficacy in patients with brain metastases. Brain exposure and drug distribution in tumor regions are important criteria for evaluation and confirmation of CNS efficacy. The aim of this PET study was therefore to determine brain distribution and exposure of 11C-labelled osimertinib administered intravenously in subjects with an intact blood-brain barrier. Eight male healthy subjects (age 52 ± 8 years) underwent one PET measurement with 11C-osimertinib. The pharmacokinetic parameters Cmax(brain) (standardized uptake value), Tmax(brain) and AUC0-90 minbrain/blood ratio were calculated. The outcome measure for 11C-osimertinib brain exposure was the total distribution volume (VT). 11C-osimertinib distributed rapidly to the brain, with higher uptake in grey than in white matter. Mean Cmax, Tmax and AUC0-90 minbrain/blood ratio were 1.5 (range 1-1.8), 13 min (range 5-30 min), and 3.8 (range 3.3-4.1). Whole brain and white matter VT were 14 mL×cm-3 (range 11-18) and 7 mL×cm-3 (range 5-12). This study in healthy volunteers shows that 11C-osimertinib penetrates the intact blood-brain barrier. The approach used further illustrates the role of molecular imaging in facilitating the development of novel drugs for the treatment of malignancies affecting the brain.

Be-TeaM: An Italian real-world observational study on second-line therapy for EGFR-mutated NSCLC patients

OBJECTIVES

Molecular diagnostics and care of non-small cell lung cancer (NSCLC) are continuously evolving. Few data document the current strategies to manage advanced NSCLC patients beyond progression in clinical practice.

PATIENTS AND METHODS

Be-TeaM is an Italian multi-center observational study conducted on consecutive EGFR-mutated stage IV NSCLC patients, progressed during/after a first-line EGFR-TKI. It consists of a retrospective phase, from first-line EGFR-TKI therapy start until study entry (i.e. beginning of the diagnostic process), and a prospective phase, until treatment choice or for 3 months if no therapy was prescribed. Primary objective was to describe the diagnostic and therapeutic approaches adopted after progression in a real-world setting.

RESULTS

Of 308 patients enrolled in 63 centers from July 2017 to June 2018, 289 were included in the analysis. In first line, 53.3 % received gefitinib, 32.5 % afatinib and 14.2 % erlotinib. The testing rate (i.e. rate of all patients undergone any biopsy -liquid and/or tissue- for the T790 M detection) was 90.7 %, with liquid biopsy being the most frequently executed. Of 262 biopsied patients, 64.5 % underwent only 1 liquid biopsy, 10.7 % only 1 tissue biopsy and 18.3 % >1 biopsy, both liquid and solid in 85.4 %. The T790M positivity rate was 45.3 %; of 166 patients undergone only a liquid biopsy and tested for the mutation, 39.8 % were T790M+ and 60.2 % T790M-/undetermined. By the observation end, 87.9 % patients had a post-progression treatment chosen, osimertinib being the most frequent among the T790M+.

CONCLUSION

Be-TeaM provides the first snapshot of current practices for the management of NSCLC patients beyond progression in Italy; in clinical practice, assessing the T790M status is not always feasible.

Treatment Response To Osimertinib In EGFR-Mutated Leptomeningeal Metastases From Non-Small Cell Lung Cancer: A Case Series

Therapy for leptomeningeal metastases (LM) from non-small cell lung cancer (NSCLC) is challenging, and conventional treatments have little impact on the disease course. We report three cases that were definitively diagnosed as LM from NSCLC with a mutation of epidermal growth factor receptor (EGFR) L858R. The systemic therapies of chemotherapy, local radiotherapy, and early generation tyrosine kinase inhibitors (TKIs) were implemented but ineffective. Three patients were treated with the third-generation TKI osimertinib at 80 mg daily, despite their different detection levels of T790M in the cerebrospinal fluid (CSF) and plasma, and achieved symptomatic remission, a decline of carcinoembryonic antigen (CEA) levels, and stable lesions. After the progression of LM, osimertinib at 160 mg daily further lengthened the quality of life and survival time of patients without any notable side effects during treatment. Recent related studies and our cases indicate that osimertinib has a positive effect on LM from EGFR-mutant NSCLC, regardless of T790M status.

Nonsmall cell lung cancer with rare exon 7 p.A289V mutation in the EGFR gene responds to Icotinib treatment: A case report

RATIONALE

Mutation p.A289V involving extracellular region of epidermal growth factor receptor (EGFR) exon 7 has not yet been reported in nonsmall cell lung cancer (NSCLC). Studies have shown p.A289V mutation responding to tyrosine kinase inhibitors (TKIs) in glioblastoma cell lines suggesting the point mutation as a potential therapeutic target. However, sufficient evidence of the effect of TKI treatment on the p.A289V mutation involved in NSCLC is not available.

PATIENT CONCERNS

An 80-year-old nonsmoker male with lung mass was suffering from severe bone pain.

DIAGNOSIS

Needle biopsy and positron emitted tomography/computed tomography were performed. The patient was diagnosed with advanced NSCLC adenocarcinoma with bone and lymphatic metastasis. Next-generation sequencing of circulating tumor DNA was performed, which identified a p.A289V mutation in the EGFR gene of the patient.

INTERVENTIONS

Our patient refused to receive chemotherapy and tried Icotinib treatment.

OUTCOMES

Our patient had a partial response to Icotinib after treatment for 5 months during the therapeutic trial by TKIs. The patient showed adverse symptoms of mild diarrhea and rash (Common Terminology Criteria for Adverse Events grade 1) during the treatment.

LESSONS

In this case, Icotinib prevented completion of the signal transduction cascade of p.A289V mutant in NSCLC. Our finding may expand the EGFR mutation spectrum for TKI treatment in NSCLC. However, the finding needs to be confirmed at a larger scale with NSCLC in Chinese and other populations.

Meeting with triumph and disaster: Osimertinib in T790M-unknown CNS progression in EGFR-mutated non-small cell lung cancer

Introduction:

Treatment paradigms for EGFR-mutated non-small cell lung cancer (NSCLC) have successfully evolved since the introduction of osimertinib. The detection of EGFR T790M mutation in plasma or tumor samples obtained at disease progression to first-/second-generation EGFR inhibitors is mandatory for osimertinib prescription. Nevertheless, pharmacokinetics properties of osimertinib guarantee its usefulness in central nervous system (CNS) disease even in the case of T790M-negative or unknown status.

Patients and methods:

In this brief report, we share the clinical histories of two patients with CNS-preeminent progression under first-/second-generation EGFR inhibitors in which it was not possible to document the presence of T790M resistance mutation.

Results:

Patient outcomes diverged dramatically due to the differential availability of off-label osimertinib.

Conclusions:

Waiting for the novel molecule to be approved and licensed in first-line treatment, our report of hope and frustration is intended to stress the opportunity of its administration in the case of CNS failure of first-line EGFR inhibition, even in the absence of T790M proof.

Therapeutic approaches for T790M mutation positive non-small-cell lung cancer

INTRODUCTION

Epidermal growth factor receptor (EGFR) mutation positive non-small cell lung cancer (NSCLC) is a subset of lung cancer with demonstrated response to targeted therapies. However, resistance to the first targeted approach usually occurs within the first year, and it is associated in 50-60% of cases to the T790M resistance mutation. Areas covered: The review provides an overview on the significance of the presence of the T790M mutation, its detection, treatment options and subsequent mechanisms of resistance. Expert commentary: Osimertinib is the current treatment option for T790M mutation positive NSCLC after progression to first or second-generation EGFR TKIs, with activity also on brain metastasis. However, the scenario is in continuous evolution and results from clinical trials are awaited in first-line setting and in combination strategies.