Clinical Response to Apatinib Combined With Brain Radiotherapy in EGFR Wild-Type and ALK-Negative Lung Adenocarcinoma With Multiple Brain Metastases

Efficacy of apatinib+radiotherapy vs radiotherapy alone in patients with advanced multiline therapy failure for non small cell lung cancer with brain metastasis

OBJECTIVE

Lung cancer is the leading cause of cancer-associated mortality worldwide. Central nervous system (CNS) metastasis is a prevalent and serious complication. The most common treatment for brain metastasis (BM) is still radiation therapy (RT). An increasing number of drugs have been shown to have intracranial activity or to sensitize tumours to radiotherapy.

METHODS

Consecutive advanced multiline therapy failure in patients with non-small-cell lung cancer (NSCLC) with BM at the authors' hospital were retrospectively reviewed. Eligible patients were divided into two groups: Apatinib+RT group and RT group. Intracranial progression-free survival (PFS) and overall survival (OS) were analysed using the Kaplan-Meier method.

RESULTS

The median intracranial PFS for the RT group and Apatinib+RT group was 5.83 months and 11.81 months (p = 0.034). The median OS for the RT group and Apatinib+RT group was 9.02 months and 13.62 months (p = 0.311). The Apatinib+RT group had a better intracranial PFS, but there were no significant differences between the two arms in OS. The Apatinib+RT group had significantly reduced symptoms caused by BM.

CONCLUSION

RT combined with apatinib could help to control intracranial metastases. The Apatinib+RT group had significantly reduced symptoms caused by BM and improved quality of life for patients, the safety of the two treatments was similar.

ADVANCES IN KNOWLEDGE

Here, we propose that RT combined with apatinib can significantly relieve brain symptoms and tolerate side-effects without affecting OS in patients with BM following failure of multiline therapy for NSCLC. Of course, this paper is a retrospective origin study, and more powerful evidence is needed to demonstrate.

Apatinib suppresses lung cancer stem-like cells by complex interplay between β-catenin signaling and mitochondrial ROS accumulation

The abnormal activation of Wnt/β-catenin signaling plays a critical role in the development of lung cancer, which is also important in the generation and maintenance of lung cancer stem cell (CSC). CSCs have unique capabilities to resist anticancer therapy, seed recurrent tumors, and disseminate to and colonize distant tissues. Apatinib, a small-molecule VEGFR2-tyrosine kinase inhibitor, shows highly efficient antitumor activity in heavily treated, chemoresistant, and metastatic lung cancer. We speculated that inhibition of Wnt/β-catenin signaling and targeting lung CSCs could be one of the anti-tumor mechanisms of apatinib. In the present study we demonstrated that apatinib repressed lung CSC-like traits by hindering sphere formation ability, lung CSC-related marker expression and decreasing chemoresistance derived stemness. Mechanistically, apatinib exerted its anti-CSC effects by inhibiting β-catenin and its downstream targets. Moreover, apatinib induced the production of reactive oxyen species (ROS), which participated in the inhibitory effects of apatinib on lung CSCs. It was found that β-catenin regulated apatinib-induced production of ROS. Inhibition or promotion of ROS production with N-acetyl-L-cysteine or H₂O₂ not only upregulated or downregulated β-catenin expression, but also prevented or promoted DNA damage, rescued or impeded sphere formation, respectively. Collectively, our findings reveal that apatinib directly inhibits β-catenin signaling and promotes ROS generation to suppress lung CSC-like characteristics. A clearer understanding of the anti-cancer mechanisms of apatinib is required for its better application in combating advanced and refractory/recurrent lung cancer when combined with conventional chemotherapy.

Continuous Low-Dose Apatinib Combined With WBRT Significantly Reduces Peritumoral Edema and Enhances the Efficacy of Symptomatic Multiple Brain Metastases in NSCLC

BACKGROUND

Symptomatic multiple brain metastases with peritumoral brain edema (PTBE) occur in non-small cell lung cancer patients (NSCLC) who are without driver mutations or are resistant to epidermal growth factor tyrosine kinase (EGFR-TKI) are often associated with an unfavorable prognosis. Whole brain radiation therapy (WBRT) which comes with many complications and unsatisfactory effects, is the only option for the treatment. Previous studies have shown that bevacizumab can reduce the volume of PTBE and improve efficiency of radiotherapy. This study evaluated the effects and safety of apatinib combined with WBRT in NSCLC patients with symptomatic multiple brain metastases and PTBE.

METHODS

We performed a retrospective review of 34 patients with symptomatic multiple brain metastases from NSCLC (number >4, and at least 1 measurable brain metastasis lesion with cerebral edema). Intracranial objective response rate (IORR), peritumoral edema and intracranial tumor volumetric measurement, Karnofsky performance status (KPS) and adverse events (AEs) were evaluated. Median intracranial progression-free survival (mIPFS) and median overall survival (mOS) were also analyzed.

RESULTS

Thirteen cases received apatinib (125 mg or 250 mg, QD, oral) combined with WBRT and 21 cases received chemotherapy combined with WBRT were inclued. Apatinib combination group can better reduce the volume of intracranial tumors and PTBE and total steroid dosage used. It was associated with a better IORR (84.6% vs 47.6%, P = 0.067), longer mIPFS (6.97 vs 4.77months; P = 0.014). There was no significant difference in mOS(7.70 vs 6.67 months; P = 0.14) between the 2 groups. The most common adverse events of apatinib combination WBRT included grade 1/2 nausea (4/13), fatigue (3/13), hypertension (2/13) and white blood cell decrease (2/13). No grade 3/4 AEs were observed.

CONCLUSION

Apatinib plus WBRT is well tolerated and may be a potential choice for relapsed or drug-resistant advanced NSCLC patients with symptomatic multiple brain metastases and PTBE.

Concurrent Apatinib and Brain Radiotherapy in Patients With Brain Metastases From Driver Mutation-negative Non-small-cell Lung Cancer: Study Protocol for an Open-label Randomized Controlled Trial

Brain radiotherapy (BR) is a well-recognized approach for multiple brain metastases (BMs) from non-small-cell lung cancer (NSCLC). However, the prognosis for these patients remains poor. Apatinib, an antiangiogenic agent targeting vascular endothelial growth factor receptor-2, has shown excellent efficacy in multiple solid tumors. This phase II (WWW. ClinicalTrials.gov Identifier: VEGFR-2 NCT03801200) randomized trial aims to evaluate the efficacy and safety of this combined modality paradigm in patients with BMs from driver mutation-negative NSCLC. This is a multicenter, open-label, randomized controlled clinical trial. A total of 90 eligible patients will be allocated in a 1:1 ratio, to either the experimental group (concurrent apatinib and BR) or the control group (BR alone). The primary endpoint is intracranial progression-free survival. The secondary endpoints include intracranial objective response rate, intracranial disease control rate, intracranial time to progression, overall survival, and occurrence of peritumoral brain edema using standardized measurement. Quality of life and adverse events will also be evaluated. Assessments will be carried out before enrollment (baseline) along with 4 and 12 weeks after radiotherapy, followed by every 12 weeks thereafter and up to 24 months. In summary, the aim of this trial is to demonstrate the clinical efficacy and safety of concurrent BR and apatinib in patients with driver mutation-negative NSCLC with multiple BMs, in efforts to expand management options for this population with poor prognosis.

Emerging and investigational targeted chemotherapy and immunotherapy agents for metastatic brain tumors

INTRODUCTION

Metastases to the central nervous system are the most common cause of malignant intracranial tumors in adults. Current standard of care includes surgery and radiation, but overall survival remains poor. A range of systemic therapies are emerging as promising treatment options for these patients.

AREAS COVERED

This study reviews novel drug regimens that are under investigation in phase 1 and 2 clinical trials. To identify relevant therapies under clinical investigation, a search was performed on http://clinicaltrials.gov and Pubmed with the keywords brain metastasis, Phase I clinical trial, and Phase II clinical trial from 2016 to 2020. The authors detail the mechanisms of action of all trial agents, outline evidence for their utility, and summarize the current state of the field.

EXPERT OPINION

Current advancements in the medical management of brain metastases can be categorized into targeted therapies, methods of overcoming treatment resistance, novel combinations of therapies, and modulation of the tumor microenvironment with a specific focus on immunotherapy. Each of these realms holds great promise for the field going forward. A more streamlined structure for enrollment into clinical trials will be a crucial step in accelerating progress in this area.