Second-line treatments of small-cell lung cancers

Repeatedly next-generation sequencing during treatment follow-up of patients with small cell lung cancer

Somatic alterations in tumors are a frequent occurrence. In small cell lung cancer (SCLC), these include mutations in the tumor suppressors TP53 and retinoblastoma (RB1). We used next generation sequencing (NGS) to study specific genetic variants and compare genetic and clinicopathological features of SCLC with healthy control genome. Ten SCLC patients receiving standard chemotherapy, between 2018 and 2019, from the First Hospital of Jilin University were included in this study. Prior patient treatment, NGS was performed using DNA isolated from blood plasma. New NGS analyses were performed after 2 and 4 treatment cycles. Four patients presented with different metastases at diagnosis. Overall, most genes tested presented missense or frameshift variants. TP53, RB1, CREBBP, FAT1 genes presented gain of stop codons. At the single-gene level, the most frequently altered genes were TP53 (8/10 patients, 80%) and RB1 (4/10 patients, 40%), followed by bromodomain containing 4 (BRD4), CREBBP, FAT1, FMS-like tyrosine kinase 3 (FLT3), KDR, poly ADP-ribose polymerase (PARP1), PIK3R2, ROS1, and splicing factor 3b subunit 1 (SF3B1) (2/10 patients, 20%). We identified 5 genes, which have not been previously reported to bear mutations in the context of SCLC. These genes include BRD4, PARP1, FLT3, KDR, and SF3B1. We observed that among the studied individuals, patients with a high number of genetic events, and in which such mutations were not eradicated after treatment, showed a worse prognosis. There has not yet been given enough attention to the above-mentioned genes in SCLC, which will have great clinical prospects for treatment.

Platinum-doublet chemotherapy as second-line treatment for relapsed patients with small-cell lung cancer: A systematic review and meta-analysis

OBJECTIVE

Optimal second-line chemotherapy for patients with relapsed small-cell lung cancer remains debatable. In addition to topotecan or amrubicin monotherapy, re-challenge with first-line platinum-doublets have been commonly used. In this study, we investigated whether platinum-doublets are suitable as second-line treatment for relapsed small-cell lung cancer.

MATERIALS AND METHODS

Studies that enrolled relapsed small-cell lung cancer and compared platinum-doublets with non-platinum-based regimens for second-line treatment were identified using PubMed and EMBASE. A meta-analysis was conducted to calculate the relative risk of objective response rate and disease control rate of the second-line chemotherapy. Subgroup analyses were conducted to focus on comparison with standard second-line regimens and sensitive relapse. Progression-free and overall survival, and adverse events were systematically reviewed.

RESULTS

Ten studies published between 2011 and 2020 were included in our analysis with a total of 1222 patients: 438 treated with platinum-doublets and 784 with non-platinum-based regimens. The objective response rates for second-line platinum-doublet and non-platinum regimens were 47.3 % [95 % CI: 40.5-54.0] and 31.5 % [95 % CI: 22.2-40.8], respectively.　Patients treated with platinum-doublets had a significantly higher objective response rate than patients with non-platinum-based regimens (RR [95 % CI]: 1.527 [1.100-2.121], p = 0.011), as well as disease control rate (RR [95 % CI]: 1.152 [1.052-1.262], p = 0.002). In a subgroup analysis comparing platinum-doublets with topotecan or amrubicin, patients treated with platinum-doublets had significantly higher objective response rate and disease control rate (RR [95 % CI]: 1.663 [1.055-2.619], p = 0.028 and 1.170 [1.021-1.340], p = 0.023 respectively). Progression-free and overall survival appeared consistent with the tumor responses. Adverse events associated with platinum-doublets appeared acceptable compared with the monotherapies.

CONCLUSION

Platinum-doublet chemotherapy as second-line treatment for patients with relapsed small-cell lung cancer can be considered as a reasonable option in comparison with non-platinum regimens.

Rova-T enhances the anti-tumor activity of anti-PD1 in a murine model of small cell lung cancer with endogenous Dll3 expression

Rovalpituzumab tesirine (Rova-T) offers a targeted therapy for ~85% of SCLC patients whose tumors express DLL3, but clinical dosing is limited due to off-target toxicities. We hypothesized that a sub-efficacious dose of Rova-T combined with anti-PD1, which alone shows a clinical benefit to ~15% of SCLC patients, might elicit a novel mechanism of action and extend clinical utility. Using a pre-clinical murine SCLC tumor model that expresses Dll3 and has an intact murine immune system, we found that sub-efficacious doses of Rova-T with anti-PD1 resulted in enhanced anti-tumor activity, compared to either monotherapy. Multiplex immunohistochemistry (IHC) showed CD4 and CD8 T-cells primarily in normal tissue immediately adjacent to the tumor. Combination treatment, but not anti-PD1 alone, increased Ki67+/CD8 T-cells and Granzyme B+/CD8 in tumors by flow cytometry and IHC. Antibody depletion of T-cell populations showed CD8+ T-cells are required for in vivo anti-tumor efficacy. Whole transcriptome analysis as well as flow cytometry and IHC showed that Rova-T activates dendritic cells and increases Ccl5, Il-12, and Icam more than anti-PD1 alone. Increased tumor expression of PDL1 and MHC1 following Rova-T treatment also supports combination with anti-PD1. Mice previously treated with Rova-T + anti-PD1 withstood tumor re-challenge, demonstrating sustained anti-tumor immunity. Collectively our pre-clinical data support clinical combination of sub-efficacious Rova-T with anti-PD1 to extend the benefit of immune checkpoint inhibitors to more SCLC patients.

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Sub-efficacious Rova-T combined with anti-PD1 regresses murine SCLC tumors.

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Anti-SCLC efficacy seen with Rova-T + anti-PD1 requires CD8 T-cells.

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Rova-T + anti-PD1 recruits and activates T-cells and dendritic cells within the tumor.

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Combination of Rova-T and anti-PD1 results in prolonged anti-tumor immunity.

In Search of the Long-Desired 'Copernican Therapeutic Revolution' in Small-Cell Lung Cancer

Small-cell lung cancer has defied our scientific community for decades. Chemotherapy has been the mainstay treatment for small-cell lung cancer (SCLC) and unlike its counterpart, non-small cell lung cancer, no significant therapeutic breakthroughs have been made since the 1970s. Among the reasons for this slow-paced therapeutic development, one that stands out is the distinctive and almost universal loss of function of the tumour suppressor genes TP53 and RB1 in this disease, for which pharmacological activation has yet to be achieved, despite having been highly sought after. Although no molecularly targeted approach has been approved for clinical practice thus far, several strategies are currently exploring the potential to drug the tumour's "Achilles heel" that stems from essential pathways regulating DNA-damage response. Most recently, we have witnessed newfound reasons to hope, as the combination of immunotherapy and systemic chemotherapy has improved survival outcomes, representing the first landmark achievement in decades and a new standard of care for patients with extensive disease SCLC. However, continuous efforts are still needed towards a better understanding of the molecular pathways that singularise this tumour to eventually identify the predictive biomarkers that might result in the development of a more rational therapeutic approach, including the use of immunotherapy combinations. In this review we aim to uncover critical aspects of the immune microenvironment and biology of SCLC and provide an overview of the current and future landscape of promising therapeutic opportunities. The challenge still stands, but regardless, we are living in exciting times to finally check SCLC off the "bucket list" of our scientific community.

Chinese Medicine Treatment Prolonged Survival in Small Cell Lung Cancer Patients: A Clinical Observation

OBJECTIVE

To evaluate the effect of Chinese medicine (CM) treatment on survival time and quality of life (QOL) in patients with small cell lung cancer (SCLC).

METHODS

This was an exploratory and prospective clinical observation. Patients diagnosed with SCLC receiving CM treatment were included and followed up every 3 months. The primary outcome was overall survival (OS), and the secondary outcomes were progression-free survival (PFS) and QOL.

RESULTS

A total of 136 patients including 65 limited-stage SCLC (LS-SCLC) patients and 71 extensive-stage SCLC (ES-SCLC) patients were analyzed. The median OS of ES-SCLC patients was 17.27 months, and the median OS of LS-SCLC was 40.07 months. The survival time was 16.27 months for SCLC patients with brain metastasis, 9.83 months for liver metastasis, 13.43 months for bone metastasis, and 18.13 months for lung metastasis. Advanced age, pleural fluid, liver and brain metastasis were risk factors, while longer CM treatment duration was a protective factor. QOL assessment indicated that after 6 months of CM treatment, scores increased in function domains and decreased in symptom domains.

CONCLUSION

CM treatment might help prolong OS of SCLC patients. Moreover, CM treatment brought the trend of symptom amelioration and QOL improvement. These results provide preliminary evidence for applying CM in SCLC multi-disciplinary treatment.

Choice of second-line systemic therapy in stage IV small cell lung cancer (SCLC) - A decision-making analysis amongst European lung cancer experts

OBJECTIVES

Stage IV small cell lung cancer (SCLC) is associated with short survival and progression after first-line systemic therapy frequently occurs within months. Although topotecan is approved for second-line treatment, its efficacy is limited, and treatment heterogeneity exists.

MATERIAL AND METHODS

The decision-making patterns for second line treatment of 13 European medical oncologists with expertise in SCLC were analyzed.

RESULTS

The two criteria most relevant to decision-making were the performance status and the interval of recurrence since first-line treatment. With an interval of less than 3 months since the end of first-line chemotherapy, 62 % of the experts recommended cyclophosphamide, doxorubicin and vincristine (CAV) for fit patients and 54 % recommended topotecan for unfit patients. For an interval of more than 6 months, a clear consensus for a re-challenge with a platinum doublet was achieved (92 %). However, there was no consensus on the second-line therapy with an interval of 3-6 months since the end of first-line therapy.

CONCLUSION

Real world practice may differ from recommendations in general guidelines and cannot always be directly derived from trial results as other factor such as habits, patient's preference, convenience or costs have to be factored in.

Phase II Trial of Carfilzomib Plus Irinotecan in Patients With Small-cell Lung Cancer Who Have Progressed on Prior Platinum-based Chemotherapy

INTRODUCTION

The purpose of this study was to evaluate the efficacy and tolerability of carfilzomib plus irinotecan (C/I) in patients with relapsed small-cell lung cancer (SCLC).

PATIENTS AND METHODS

Patients with SCLC who progressed after 1 platinum-containing regimen for recurrent or metastatic disease were eligible. Patients were stratified as: sensitive (SS) (progressive disease > 90 days after chemotherapy) or refractory (RS) (progressive disease 30 to 90 days after chemotherapy) and received up to 6 cycles of C/I; imaging was performed every 2 cycles. The primary endpoint was 6-month overall survival (OS).

RESULTS

All 62 patients enrolled were evaluable for efficacy and adverse events. 6-month OS was 59% in the platinum SS and 54% in the platinum RS. The overall response rate was 21.6% (2.7% complete response, 18.9% partial response) in SS (n = 37) and 12.5% (all partial response) in RS (n = 25). The disease control rate was 68% (SS) and 56% (RS). Progression-free survival and OS were 3.6 months (95% confidence interval [CI], 2.6-4.6 months) and 6.9 months (95% CI, 4.3-12.3 months) in SS, and 3.3 months (95% CI, 1.8-3.9 months) and 6.8 months (95% CI, 4.1-11 months) in RS. Twenty-nine (47%) patients experienced ≥ grade 3 adverse events; 8 (12.9%) subjects had grade 4 toxicities. Three treatment-related deaths occurred: myocardial infarction (possible), lung infection (possible), and sepsis (probable).

CONCLUSION

In patients with relapsed SCLC, C/I was effective in the treatment of SS and RS. With 4.8% grade 5 toxicity, C/I is a viable option for relapsed patients with SCLC with performance status 0 to 1, particularly in platinum-resistant patients, or subjects who cannot receive immunotherapy.

Surgery as a Potential Treatment Option for Patients With Stage III Small-Cell Lung Cancer: A Propensity Score Matching Analysis

Surgery is commonly recommended for patients with stage I small-cell lung cancer (SCLC), whereas chemotherapy and radiotherapy are considered the standard treatment for patients with stage III SCLC. However, recent studies have suggested that a small proportion of patients with SCLC at an advanced stage may benefit from surgical resection. Therefore, in this study, we investigated the effectiveness of surgery in patients with stage III SCLC. Patients were selected from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2013. Propensity score matching (PSM) was used to eliminate any clinical bias. The overall survival (OS) was determined using the Kaplan–Meier method and compared using the log-rank test. The Cox proportional-hazards model was used to identify the effect of surgery on the OS. Of 9606 patients with stage III SCLC, 234 underwent surgery. Compared with the non-surgical group, a higher proportion of patients undergoing surgery had T1 and N0-N1 disease (risen by 10.7% for T1; 12.6% for N0-N1) and a lower proportion had T4 and N3 disease (decreased by 14.3% for T4; 12.5% for N3). The Kaplan-Meier analysis showed that patients who underwent surgery had a better OS before and after PSM. The multivariate analysis showed that surgery was beneficial for patients with stage III SCLC (HR: 0.651, 95% CI 0.524–0.808, P < 0.001). In conclusion, surgical resection might be associated with improved OS for patients with stage III SCLC and may be considered for the treatment of these patients. Further prospective studies are required to confirm these findings.

Prognostic value of delta-like protein 3 combined with thyroid transcription factor-1 in small-cell lung cancer

Rovalpituzumab tesirine is a promising delta-like protein 3 (DLL3)-targeted antibody-drug conjugate for the treatment of small-cell lung cancer (SCLC). Thyroid transcription factor-1 (TTF-1) and DLL3 protein are associated with SCLC, and may be used to identify patients, who respond to the DLL3-targeted therapy. However, little is known about the expression pattern of the DLL3 protein, and the prognostic value of DLL3 and TTF-1 for SCLC. A total of 335 patients with SCLC were identified, including 11 patients with paired biopsy of primary site and lobectomy specimens, and 37 patients with paired specimens of primary and metastatic site. The DLL3 expression levels of individuals were evaluated using the anti-DLL3 antibody. No differences in DLL3 expression levels were observed in paired biopsy and lobectomy specimens (P=0.774), and paired primary and metastatic sites (P=0.472). SCLC cases with high DLL3 expression levels were more frequent in male patients (P=0.041), smokers (P=0.023) and patients with positive TTF-1 expression (P=0.006) compared with DLL3-low SCLC. DLL3-high SCLC exhibited worse overall survival compared with DLL3-low SCLC (log-rank test, P=0.007). Patients with TTF-1+ SCLC experienced a significantly worse overall survival compared with patients with TTF-1- SCLC (P<0.001). DLL3-low/TTF-1- was defined as a distinct molecular subgroup of SCLC with optimal prognosis (P<0.001). DLL3-low/TTF-1- was an independent prognostic marker for SCLC (P=0.001). In conclusion, the present study, to the best of our knowledge, provided novel evidence for SCLC intratumoral and intertumoral homogeneity with the identification of DLL3 protein levels. Therefore, it is reliable to use biopsy specimens to evaluate DLL3 expression levels for identification of patients who may benefit from DLL3-targeted therapy. In addition, DLL3 and TTF-1 are two protein markers with potential clinical value in risk stratification for patients with SCLC.

N-Butanol Subfraction of Brassica Rapa L. Promotes Reactive Oxygen Species Production and Induces Apoptosis of A549 Lung Adenocarcinoma Cells via Mitochondria-Dependent Pathway

Brassica rapa L., an edible and medical vegetable, has been traditionally used in Uyghur folk medicine to treat coughs and asthma in the Xinjiang Uygur Autonomous Region, China. In this study, we prepared an n-butanol subfraction of B. rapa L. (BRBS) and investigated the anti-tumor effect on A549 lung adenocarcinoma cells. The proliferation of A549 cells was significantly inhibited by BRBS treatment in a dose- and time-dependent manner. BRBS significantly induced cell cycle arrest and apoptosis in A549 cells through increased reactive oxygen species (ROS) production and mitochondrial dysfunction characterized by a reduction in mitochondrial membrane potential and the release of cytochrome c, which promoted caspase-3 and poly(ADP-ribose) polymerase processing. Moreover, BRBS significantly suppressed the migration of A549 cells in vitro. These results suggest that BRBS inhibited A549 cell proliferation through increased ROS production and the mitochondria-dependent apoptosis pathway. Consequently, BRBS might be a potential candidate for the treatment of lung cancer.

Flotillin1 promotes EMT of human small cell lung cancer via TGF-β signaling pathway

Objective

Small cell lung carcinoma (SCLC) is considered one of the most aggressive types of lung cancer due to its rapid growth and early metastasis. No tumor markers or therapeutic targets have been demonstrated to be specific or effective in SCLC to date. This study aims to evaluate the potential of Flotillin1 (Flot1) as a target of SCLC treatment.

Methods

Flot1 expression level in the tissue of SCLC and other tissue of lung disease was detected using immunohistochemical staining. Transwell and Matrigel assays were employed to examine migration and invasion of cancer cells. Flow cytometry and xCELLigence system were used to evaluate cell apoptosis and cell viability, respectively. Expression levels of Flot1, epithelial-mesenchymal transition (EMT) marker E-cadherin, vimentin, cyclinD1, TGF-β-Smad2/3, and p-AKT were examined using Western blot. Furthermore, xenograft tumor in nude mice was used to evaluate the growth and metastasis of NCI-H446 cells in vivo.

Results

Our results demonstrated that Flot1 is highly expressed in SCLC samples and that its expression correlates strongly with clinical stage, distant metastasis, and poor survival. The knockdown of Flot1 decreased the growth, migration, and invasiveness of SCLC cells and reversed EMT phenotype in vitro and in vivo, while enhanced Flot1 expression exhibited the opposite behavior. Gene expression profile analysis demonstrated that Flot1-regulated genes frequently mapped to the AKT and TGF-β-Smad2/3 pathways. Our results further revealed that Flot1 affected the progression of SCLC via regulation of EMT progression.

Conclusions

These findings indicated an oncogenic role of Flot1 via promoting EMT in SCLC and suggested its potential as a tumor marker and prognostic indicator.