Prognostic significance of circulating tumor cells and tumor related transcripts in small cell lung cancer: A step further to clinical implementation

Small-cell lung cancer (SCLC) is a fatal disease with limited treatment options. Circulating tumor cells (CTCs) in liquid biopsy samples may serve as predictive and prognostic biomarkers; but the analysis of CTCs is still challenging. By using microfluidic or density gradient CTC enrichment in combination with immunofluorescent (IF) staining or qPCR of CTC-related transcripts, we achieved a 60.8% to 88.0% positivity in SCLC blood samples. Epithelial and neuroendocrine transcripts including the druggable target DLL3 were associated with shorter overall survival (OS), indicating the clinical value of these markers in terms of differential diagnosis and treatment decisions. High CTC counts and the presence of CTC duplets detected by IF staining were prognostic for OS, and thus may serve as indicators of disease progression or therapy failure. In patient samples with high CTC load detected by IF staining, a concordance of the transcripts positivity in circulating free plasma RNA and CTCs was observed. Our data emphasize the role of CTCs and CTC-related transcripts and underline the clinical value of liquid biopsy analysis in SCLC.

The Landsteiner lung cancer research platform (LALUCA) : Objectives, methodology and implementation of a real-world clinical lung cancer registry

BACKGROUND

Lung cancer is a major health burden in Austria; however, limited real-world data exist on the diagnostic and treatment reality of lung cancer patients in Austria. The collection of high-quality data in a clinical setting is needed to gain insights into the real-world diagnostic and therapeutic management of lung cancer patients.

METHODS

The Karl Landsteiner Institute for Lung Research and Pulmonary Oncology implemented the Landsteiner lung cancer research platform (LALUCA), recruiting unselected lung cancer patients from two high volume centers in Vienna. This article describes the objectives, design, methodology of the registry and the process of implementation.

RESULTS

A multidisciplinary team of lung cancer specialists created a custom designed variable catalogue for the LALUCA platform consisting of 17 categories with 180 variables. Detailed information on clinical characteristics, diagnostic interventions, molecular pathology as well as curative and palliative treatment modalities are collected. During an implementation phase in 2020, the platform was optimized using the data of 50 patients. Since then a total of 1200 patients have been enrolled. Recruitment for the registry is ongoing with a recruitment rate of approximately 400 patients per year.

CONCLUSION

The LALUCA registry is a web-based platform for the collection of real-world clinical data of lung cancer patients. Combining a large number of patients with a focus on gathering comprehensive data on diagnosis and treatment, the LALUCA registry provides a tool for investigation, evaluation, and improvement of the clinical management, survival and quality of care of Austrian lung cancer patients.

Mobocertinib in Patients with EGFR Exon 20 Insertion-Positive Non-Small Cell Lung Cancer (MOON): An International Real-World Safety and Efficacy Analysis

EGFR exon 20 (EGFR Ex20) insertion mutations in non-small cell lung cancer (NSCLC) are insensitive to traditional EGFR tyrosine kinase inhibitors (TKIs). Mobocertinib is the only approved TKI specifically designed to target EGFR Ex20. We performed an international, real-world safety and efficacy analysis on patients with EGFR Ex20-positive NSCLC enrolled in a mobocertinib early access program. We explored the mechanisms of resistance by analyzing postprogression biopsies, as well as cross-resistance to amivantamab. Data from 86 patients with a median age of 67 years and a median of two prior lines of treatment were analyzed. Treatment-related adverse events (TRAEs) occurred in 95% of patients. Grade ≥3 TRAEs were reported in 38% of patients and included diarrhea (22%) and rash (8%). In 17% of patients, therapy was permanently discontinued, and two patients died due to TRAEs. Women were seven times more likely to discontinue treatment than men. In the overall cohort, the objective response rate to mobocertinib was 34% (95% CI, 24-45). The response rate in treatment-naïve patients was 27% (95% CI, 8-58). The median progression-free and overall survival was 5 months (95% CI, 3.5-6.5) and 12 months (95% CI, 6.8-17.2), respectively. The intracranial response rate was limited (13%), and one-third of disease progression cases involved the brain. Mobocertinib also showed antitumor activity following EGFR Ex20-specific therapy and vice versa. Potential mechanisms of resistance to mobocertinib included amplifications in MET, PIK3CA, and NRAS. Mobocertinib demonstrated meaningful efficacy in a real-world setting but was associated with considerable gastrointestinal and cutaneous toxicity.

Effect of short-term storage of blood samples on gene expression in lung cancer patients

OBJECTIVES

The stability of gene transcripts associated with the presence of circulating tumor cells (CTCs) has been predominantly studied in cultured cancer cell lines added to blood samples under artificial conditions. In the present study the effect of storage on CTC-related transcripts was assessed in blood samples taken from patients with non-small lung cancer (n=58).

METHODS

The blood samples were split in two equal parts to compare the gene expression with and without storage for 24 h at ambient temperature without preservative added. After enrichment using the microfluidic Parsortix^® technology, the expression levels of selected genes were assessed using quantitative PCR following a gene-specific pre-amplification. The prognostic relevance of each gene in fresh and stored blood samples was evaluated using the R-package Survminer.

RESULTS

Some genes were either not affected (TWIST1, CDH5, CK19) or upregulated upon storage (NANOG, MET, UCHL1) but still associated with poor prognosis. In contrast, ERBB3, PTHLH, EpCAM, and TERT were no longer associated with the overall survival of the patients.

CONCLUSIONS

The study demonstrates the surprising stability of CTC-related transcripts, which makes overnight shipping of native blood samples possible. Careful verification is required when using model systems - such as normal blood spiked with tumor cells - or other CTC-related markers, as individual transcripts may respond differently to storage.

Real-world experience with capmatinib in MET exon 14-mutated non-small cell lung cancer (RECAP): a retrospective analysis from an early access program

Background

Patients with non-small cell lung cancer (NSCLC) presenting with mesenchymal-epithelial transition (MET) exon 14 skipping mutation have an unfavorable prognosis with standard treatments. Capmatinib is a selective MET inhibitor, which showed promising efficacy in this patient population in early trials.

Methods

We performed a retrospective, international, multicenter efficacy and safety analysis in patients with NSCLC treated with capmatinib in an early access program between March 2019 and December 2021.

Results

Data from 81 patients with advanced MET exon 14 mutated NSCLC treated with capmatinib in first- or later-line therapy were analyzed. Median age was 77 years (range, 48-91), 56% were women, 86% had stage IV disease, and 27% had brain metastases. For all patients, the objective response rate (ORR) to capmatinib was 58% (95% CI, 47-69), whereas it was 68% (95% CI, 50-82) in treatment-naïve and 50% (95% CI, 35-65) in pretreated patients. The median progression-free survival was 9.5 months (95% CI, 4.7-14.3), whereas it was 10.6 months (95% CI, 5.5-15.7) in first-line and 9.1 months (95% CI, 3.1-15.1) in pretreated patients. After a median follow-up of 11.0 months, the median overall survival was 18.2 months (95% CI, 13.2-23.1). In patients with measurable brain metastases (n = 11), the intracranial ORR was 46% (95% CI, 17-77). Capmatinib showed a manageable safety profile. Grade ⩾ 3 treatment-related adverse events included peripheral edema (13%), elevated creatinine (4%), and elevated liver enzymes (3%).

Conclusion

In patients with MET exon 14 skipping mutation, capmatinib showed durable systemic and intracranial efficacy and a manageable safety profile. This analysis confirms previously reported phase II data in a real-world setting.

Cancer Stem Cell-Like Circulating Tumor Cells Are Prognostic in Non-Small Cell Lung Cancer

Despite recent advances in the treatment of non-small cell lung cancer (NSCLC), less than 10% of patients survive the first five years when the disease has already spread at primary diagnosis. Methods: Blood samples were taken from 118 NSCLC patients at primary diagnosis or at progression of the disease before the start of a new treatment line and enriched for circulating tumor cells (CTCs) by microfluidic Parsortix™ (Angle plc, Guildford GU2 7AF, UK) technology. The gene expression of epithelial cancer stem cell (CSC), epithelial to mesenchymal (EMT), and lung-related markers was assessed by qPCR, and the association of each marker with overall survival (OS) was evaluated using log-rank tests. Results: EpCAM was the most prevalent transcript, with 53.7% positive samples at primary diagnosis and 25.6% at recurrence. EpCAM and CK19, as well as NANOG, PROM1, TERT, CDH5, FAM83A, and PTHLH transcripts, were associated with worse OS. However, only the CSC-specific NANOG and PROM1 were related to the outcome both at primary diagnosis (NANOG: HR 3.21, 95%CI 1.02–10.14, p = 0.016; PROM1: HR 4.23, 95% CI 0.65–27.56, p = 0.007) and disease progression (NANOG: HR 4.17, 95%CI 0.72–24.14, p = 0.025; PROM1: HR 4.77, 95% CI 0.29–78.94, p = 0.032). Conclusions: The present study further underlines the relevance of the molecular characterization of CTCs. Our multi-marker analysis highlighted the prognostic value of cancer stem cell-related transcripts at primary diagnosis and disease progression.

Selpercatinib in RET fusion-positive non-small-cell lung cancer (SIREN): a retrospective analysis of patients treated through an access program

INTRODUCTION

Rearranged during transfection (RET) gene fusions are rare genetic drivers in non-small cell lung cancer (NSCLC). Selective RET-inhibitors such as selpercatinib have shown therapeutic activity in early clinical trials; however, their efficacy in the real-world setting is unknown.

METHODS

A retrospective efficacy and safety analysis was performed on data from RET fusion-positive NSCLC patients who participated in a selpercatinib access program (named patient protocol) between August 2019 and January 2021.

RESULTS

Data from 50 patients with RET fusion-positive advanced NSCLC treated with selpercatinib at 27 centers in 12 countries was analyzed. Most patients were Non-Asian (90%), female (60%), never-smokers (74%), with a median age of 65 years (range, 38-89). 32% of the patients had known brain metastasis at the time of selpercatinib treatment. Overall, 13 patients were treatment-naïve, while 37 were pretreated with a median of three lines of therapy (range, 1-8). The objective response rate (ORR) was 68% [95% confidence interval (CI), 53-81] in the overall population. The disease control rate was 92%. The median progression-free survival was 15.6 months (95% CI, 8.8-22.4) after a median follow-up of 9 months. In patients with measurable brain metastases (n = 8) intracranial ORR reached 100%. In total, 88% of patients experienced treatment-related adverse events (TRAEs), a large majority of them being grade 1 or 2. The most common grade ⩾ 3 TRAEs were increased liver enzyme levels (in 10% of patients), prolonged QTc time (4%), abdominal pain (4%), hypertension (4%), and fatigue/asthenia (4%). None of patients discontinued selpercatinib treatment for safety reasons. No new safety concerns were observed, nor where there any treatment-related death.

CONCLUSIONS

In this real-world setting, the selective RET-inhibitor selpercatinib demonstrated durable systemic and intracranial antitumor activity in RET fusion-positive NSCLC and was well tolerated.

Later-Line Treatment with Lorlatinib in ALK- and ROS1-Rearrangement-Positive NSCLC: A Retrospective, Multicenter Analysis

In clinical practice, patients with anaplastic lymphoma kinase (ALK)-rearrangement–positive non–small-cell lung cancer commonly receive sequential treatment with ALK tyrosine kinase inhibitors. The third-generation agent lorlatinib has been shown to inhibit a wide range of ALK resistance mutations and thus offers potential benefit in later lines, although real-world data are lacking. This multicenter study retrospectively investigated later-line, real-world use of lorlatinib in patients with advanced ALK- or ROS1-positive lung cancer. Fifty-one patients registered in a compassionate use program in Austria, who received second- or later-line lorlatinib between January 2016 and May 2020, were included in this retrospective real-world data analysis. Median follow-up was 25.3 months. Median time of lorlatinib treatment was 4.4 months for ALK-positive and 12.2 months for ROS-positive patients. ALK-positive patients showed a response rate of 43.2%, while 85.7% percent of the ROS1-positive patients were considered responders. Median overall survival from lorlatinib initiation was 10.2 and 20.0 months for the ALK- and ROS1-positive groups, respectively. In the ALK-positive group, lorlatinib proved efficacy after both brigatinib and alectinib. Lorlatinib treatment was well tolerated. Later-line lorlatinib treatment can induce sustained responses in patients with advanced ALK- and ROS1-positive lung cancer.

Treatment of ALK-rearranged non-small-cell lung cancer with brigatinib as second or later lines: real-world observations from a single institution

The second-generation ALK tyrosine kinase inhibitor brigatinib has recently been approved in the European Union for use after crizotinib treatment in patients with EML4-ALK-rearranged lung cancer. In the current study, brigatinib was investigated as second-line or later-line treatment in 35 patients who had developed resistance to crizotinib, ceritinib, or alectinib. Most patients (68.6%) received brigatinib as second or third line (range: second to 12th line). In the total cohort, complete and partial responses were obtained for 9.1 and 75.8%, respectively. Overall median progression-free survival was 9.9 months, whereas the largest treatment cohort (brigatinib after crizotinib failure) showed a median progression-free survival of 8.4 months. Fifty-four percent of patients with baseline brain metastases responded to brigatinib treatment. Brigatinib was highly effective after crizotinib and ceritinib failure. Six patients had received alectinib as monotherapy, second-line, or third line before brigatinib; of these, four experienced partial responses and two progressed responses. Brigatinib treatment was well tolerated.

Effects of salinomycin and niclosamide on small cell lung cancer and small cell lung cancer circulating tumor cell lines

Tumor dissemination and recurrence is attributed to highly resistant cancer stem cells (CSCs) which may constitute a fraction of circulating tumor cells (CTCs). Small cell lung cancer (SCLC) constitutes a suitable model to investigate the relation of CTCs and CSCs due to rapid tumor spread and a high number of CTCs. Expansion of five SCLC CTC lines (BHGc7, 10, 16, 26 and UHGc5) in vitro at our institution allowed for the analysis of CSC markers and cytotoxicity of the CSC-selective drugs salinomycin and niclosamide against CTC single cell suspensions or CTC spheroids/ tumorospheres (TOS). Salinomycin exerted dose-dependent cytotoxicity against the SCLC lines but, with exception of BHGc7 TOS, there was no markedly enhanced activity against TOS. Similarly, niclosamide exhibits high activity against BHGc7 TOS and UHGc5 TOS but not against the other CTC spheroids. High expression of the CSC marker CD133 was restricted to three SCLC tumor lines and the BHGc10 CTC line. All SCLC CTCs are CD24-positive but lack expression of CD44 and ABCG2 in contrast to the SCLC tumor lines which show a phenotype more similar to that of CSCs. The stem cell marker SOX2 was found in all CTC lines and SCLC GLC14/16, whereas elevated expression of Oct-3/4 and Nanog was restricted to BHGc26 and UHGc5. In conclusion, the SCLC CTCs established from patients with relapsed disease lack a typical CSC phenotype in respect to chemosensitivity to CSC-selective drugs, surface markers, expression of pluripotent stem cell and transcription factors.

Molecular Characterization of Circulating Tumor Cells Enriched by A Microfluidic Platform in Patients with Small-Cell Lung Cancer

At initial diagnosis, most patients with small-cell lung cancer (SCLC) present with metastatic disease with a high number of tumor cells (CTCs) circulating in the blood. We analyzed RNA transcripts specific for neuroendocrine and for epithelial cell lineages, and Notch pathway delta-like 3 ligand (DLL3), the actionable target of rovalpituzumab tesirine (Rova-T) in CTC samples. Peripheral blood samples from 48 SCLC patients were processed using the microfluidic Parsortix™ technology to enrich the CTCs. Blood samples from 26 healthy donors processed in the same way served as negative controls. The isolated cells were analyzed for the presence of above-mentioned transcripts using quantitative PCR. In total, 16/51 (31.4%) samples were CTC-positive as determined by the expression of epithelial cell adhesion molecule 1 (EpCAM), cytokeratin 19 (CK19), chromogranin A (CHGA), and/or synaptophysis (SYP). The epithelial cell lineage-specific EpCAM and/or CK19 gene expression was observed in 11 (21.6%) samples, and positivity was not associated with impaired survival. The neuroendocrine cell lineage-specific CHGA and/or SYP were positive in 13 (25.5%) samples, and positivity was associated with poor overall survival. DLL3 transcripts were observed in four (7.8%) SCLC blood samples and DLL3-positivity was similarly associated with poor overall survival (OS). CTCs in SCLC patients can be assessed using epithelial and neuroendocrine cell lineage markers at the molecular level. Thus, the implementation of liquid biopsy may improve the management of lung cancer patients, in terms of a faster diagnosis, patient stratification, and on-treatment therapy monitoring.