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

Development of brain metastases in patients managed with non-curative thoracic radiotherapy for stage II/III non-small cell lung cancer

BACKGROUND

This retrospective study analyzed the incidence of subsequent brain metastases after palliative radiotherapy or chemoradiation in patients with stage II/III non-small cell lung cancer (NSCLC). Risk factors for brain metastases development and survival after diagnosis were evaluated.

METHODS

Different baseline parameters including but not limited to age, stage and target volume size were assessed. Outcomes were abstracted from electronic health records. Uni- and multivariate tests were performed.

RESULTS

The study included 102 patients and found an actuarial risk of brain metastases of 15% (standard error ± 4) at one year and 20% (± 5) at two years. The maximum time interval was 15 months from start of radiation treatment. A non-significant survival difference was observed (median 12 months without versus 8.3 months with brain metastases, p = 0.21). Incidence was higher in patients with N2/3 stage, larger planning target volume size, and younger age (univariately significant factors). Trends were seen for stage III and adenocarcinoma histology. The multivariate analysis confirmed age as the most important risk factor.

CONCLUSION

The risk of brain metastases development was comparable to that reported in studies of curative chemoradiation. All events occurred within 15 months of follow-up, suggesting that long-term surveillance imaging may not be warranted. Patients younger than 60 years had a very high risk of brain metastases development.

KRASG12C Inhibitors in Non-Small Cell Lung Cancer: A Review

Rat sarcoma virus (RAS) GTPase is one of the most important drivers of non-small cell lung cancer (NSCLC). RAS has three different isoforms (Harvey rat sarcoma viral oncogene homolog [HRAS], Kirsten rat sarcoma viral oncogene homolog [KRAS] and Neuroblastoma ras viral oncogene homolog [NRAS]), of which KRAS is most commonly mutated in NSCLC. The mutated KRAS protein was historically thought to be "undruggable" until the development of KRASG12C inhibitors. In this review, from the aspect of brain metastasis, we aim to provide an overview of the advances in therapies that target KRASG12C, the limitations of the current treatments, and future prospects in patients with KRAS p.G12C mutant NSCLC.

Liquid biopsy for the management of NSCLC patients under osimertinib treatment

Therapeutic management of NSCLC patients is quite challenging as they are mainly diagnosed at a late stage of disease, and they present a high heterogeneous molecular profile. Osimertinib changed the paradigm shift in treatment of EGFR mutant NSCLC patients achieving significantly better clinical outcomes. To date, osimertinib is successfully administered not only as first- or second-line treatment, but also as adjuvant treatment while its efficacy is currently investigated during neoadjuvant treatment or in stage III, unresectable EGFR mutant NSCLC patients. However, resistance to osimertinib may occur due to clonal evolution, under the pressure of the targeted therapy. The utilization of liquid biopsy as a minimally invasive tool provides insight into molecular heterogeneity of tumor clonal evolution and potent resistance mechanisms which may help to develop more suitable therapeutic approaches. Longitudinal monitoring of NSCLC patients through ctDNA or CTC analysis could reveal valuable information about clinical outcomes during osimertinib treatment. Therefore, several guidelines suggest that liquid biopsy in addition to tissue biopsy should be considered as a standard of care in the advanced NSCLC setting. This practice could significantly increase the number of NSCLC patients that will eventually benefit from targeted therapies, such as EGFR TKIs.

Brigatinib combined with cetuximab in the fifth-line treatment of non-small cell lung cancer with EGFR p.C797S mutation in critically ill patients: a report of two cases and literature review

For critically ill patients with non-small cell lung cancer (NSCLC) in need of life-saving treatment, there is currently no reported evidence regarding the use of medication specifically targeting epidermal growth factor receptor ( EGFR ) p.C797S mutation, which is known to cause resistance to third-generation tyrosine kinase inhibitors (TKIs). Our report aims to investigate and explore treatment strategies to overcome resistance associated with EGFR p.C797S mutation in order to provide potential therapeutic options for these patients. Here, we reported two cases with NSCLC who initially harbored an EGFR -sensitive mutation and were both treated with osimertinib, a third-generation TKI. Next-generation sequencing tests conducted prior to the initiation of fifth-line therapy in critically ill patients revealed the presence of EGFR p.C797S mutations in both patients, suggesting acquired resistance. In the course of fifth-line therapy, the administration of a combination of brigatinib and cetuximab proved vital in saving critically ill patients, moderately extending their overall survival period. Our findings suggested that a combined regimen of brigatinib and cetuximab could serve as a potentially life-saving therapeutic strategy for critically ill patients with NSCLC, particularly those demonstrating EGFR p.C797S-mediated resistance. Further studies, however, are required to validate and expand upon these promising findings.

A Phase II Trial of Bevacizumab in Patients with Recurrent/Progressive Solid Tumor Brain Metastases That Have Progressed Following Whole-Brain Radiation Therapy

Patients with solid tumor brain metastases that progress after whole-brain radiation have limited options. This prospective trial investigated the efficacy, safety, and tolerability of bevacizumab as salvage therapy in this population. Eligible patients received bevacizumab 10 mg/kg intravenously every 2 weeks until progression. The primary endpoint was radiologic response using Response Assessment in Neuro-Oncology (RANO) criteria. The secondary endpoints were progression-free survival (PFS), overall survival (OS), duration of response, and safety. Quality of life (QOL) was studied using the Functional Assessment of Cancer Therapy-Brain (FACT-Br) scale. Twenty-seven patients were enrolled, with twenty-four having evaluable data for response. The majority of histologies (n = 21, 78%) were breast cancer. The remaining histologies were non-small-cell lung cancer (n = 4, 15%), neuroendocrine cancer (n = 1, 3%), and papillary fallopian serous adenocarcinoma (n = 1, 3%). Eighteen patients had radiologic response, with two patients demonstrating partial response (8.33%) and sixteen patients demonstrating stable disease (66.7%). The median duration of response was 203 days. PFS at 6 months was 46%, median PFS was 5.3 m, and median OS was 9.5 m. Treatment was well tolerated, with six patients experiencing grade 3 lymphopenia and hypertension. There was one grade 3 thromboembolism. QOL was not negatively impacted. Bevacizumab is a safe and feasible salvage treatment with durable response and favorable overall survival for patients with progressive brain metastases after whole-brain radiation.

Osimertinib readministration for central nervous system metastases in non-small cell lung cancer positive for EGFR activating mutations

BACKGROUND

Osimertinib shows pronounced efficacy for EGFR mutation-positive non-small cell lung cancer (NSCLC) including associated central nervous system (CNS) metastases. Tumors inevitably develop resistance to the drug, however. Osimertinib is sometimes readministered after completion of standard chemotherapy. To clarify which patients might receive benefit from osimertinib readministration, we have retrospectively assessed its efficacy with a focus on CNS metastases.

METHODS

A retrospective analysis of medical records was performed for 21 patients who underwent osimertinib readministration at Kyushu University Hospital between March 2016 and April 2023. CNS metastases were evaluated according to modified Response Evaluation Criteria in Solid Tumors (RECIST).

RESULTS

Among the 21 enrolled patients, 16 individuals had target lesions on the basis of RECIST. One (6.3%) of these 16 patients achieved a partial response to osimertinib readministration, with the remaining 15 patients showing stable or progressive disease. The median overall progression-free survival (PFS) and median overall survival for all 21 patients were 3.8 and 13.9 months, respectively. The efficacy of osimertinib readministration for CNS metastases was evaluable in eight patients including five individuals with leptomeningeal metastases. The objective response rate for CNS metastases and the improvement rate for leptomeningeal metastases were both 100%. The median PFS with regard to CNS or non-CNS lesions for these eight patients was 24.7 and 10.5 months, respectively.

CONCLUSIONS

Osimertinib readministration showed limited efficacy for non-CNS lesions but excellent efficacy for CNS metastases, suggesting that such treatment is an option for EGFR-mutated NSCLC patients with CNS metastases.

Efficacy and safety of EGFR-TKI combined with WBRT vs. WBRT alone in the treatment of brain metastases from NSCLC: a systematic review and meta-analysis

Background

The efficacy and safety of combining epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) with whole-brain radiotherapy (WBRT) for treating brain metastases in non-small cell lung cancer patients remains to be determined.

Methods

A systematic search was conducted using databases including PubMed, Embase, Web of Science, Cochrane, Wanfang, and China National Knowledge Infrastructure (CNKI), aiming to identify relevant clinical studies on the treatment of brain metastases originating from non-small cell lung cancer through the combination of EGFR-TKI and WBRT. Statistical analysis was performed utilizing Stata 17.0 software, covering clinical studies published until March 1, 2023.

Results

This analysis incorporated 23 randomized controlled trials (RCTs), involving a total of 2,025 patients. Of these, 1,011 were allocated to the group receiving both EGFR-TKI and WBRT, while 1,014 were assigned to the WBRT alone group. The findings reveal that the combination of EGFR-TKI and WBRT significantly improves the intracranial objective remission rate (RR = 1.57, 95% CI: 1.42-1.74, p < 0.001), increases the intracranial disease control rate (RR = 1.30, 95% CI: 1.23-1.37, p < 0.001), and enhances the 1-year survival rate (RR = 1.48, 95% CI: 1.26-1.73, p < 0.001). Additionally, this combined treatment was associated with a significant survival advantage (RR = 1.48, 95% CI: 1.26-1.73, p < 0.001) and a reduced incidence of adverse effects (RR = 0.65, 95% CI: 0.51-0.83, p < 0.001), particularly with respect to nausea and vomiting (RR = 0.54, 95% CI: 0.37-0.81, p = 0.002) and myelosuppression (RR = 0.59, 95% CI: 0.40-0.87, p = 0.008). However, no statistically significant differences were observed for diarrhea (RR = 1.15, 95% CI: 0.82-1.62, p = 0.418), and skin rash (RR = 1.35, 95% CI: 0.88-2.07, p = 0.164).

Conclusion

In contrast to WBRT alone, the combination of EGFR-TKI and WBRT significantly improves intracranial response, enhancing the objective response rate, disease control rate, and 1-year survival rate in NSCLC patients with brain metastases. Moreover, aside from mild cases of rash and diarrhea, there is no statistically significant increase in the incidence of additional adverse effects. Based on the comprehensive evidence collected, the use of third-generation EGFR-TKI combined with WBRT is recommended as the preferred treatment for NSCLC patients with brain metastases, offering superior management of metastatic brain lesions.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/#, CRD42023415566.

The study of primary and acquired resistance to first-line osimertinib to improve the outcome of EGFR-mutated advanced Non-small cell lung cancer patients: the challenge is open for new therapeutic strategies

The development of targeted therapy in epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC) patients has radically changed their clinical perspectives. Current first-line standard treatment for advanced disease is commonly considered third-generation tyrosine kinase inhibitors (TKI), osimertinib. The study of primary and acquired resistance to front-line osimertinib is one of the main burning issues to further improve patients' outcome. Great heterogeneity has been depicted in terms of duration of clinical benefit and pattern of progression and this might be related to molecular factors including subtypes of EGFR mutations and concomitant genetic alterations. Acquired resistance can be categorized into two main classes: EGFR-dependent and EGFR-independent mechanisms and specific pattern of progression to first-line osimertinib have been demonstrated. The purpose of the manuscript is to provide a comprehensive overview of literature about molecular resistance mechanisms to first-line osimertinib, from a clinical perspective and therefore in relationship to emerging therapeutic approaches.

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.

Current and Emerging Treatment Options for Patients with Metastatic EGFR-Mutated Non-small Cell Lung Cancer After Progression on Osimertinib and Platinum-Based Chemotherapy: A Podcast Discussion

Patients with metastatic epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC) are widely treated with osimertinib, the preferred first-line treatment option. However, disease progression inevitably occurs, driven by EGFR-dependent or EGFR-independent mechanisms of resistance. Platinum-based chemotherapy is the recommended treatment following progression with osimertinib but responses to platinum-based chemotherapy are transient. Salvage therapies, which are used after progression on platinum-based chemotherapy, have poor clinical outcomes in addition to substantial toxicity. In this podcast, we discuss the current treatment landscape and emerging therapeutic options for patients with metastatic EGFR-mutated NSCLC whose disease has progressed following treatment with osimertinib and platinum-based chemotherapy.Podcast audio available for this article.