DB-1314, a novel DLL3-targeting ADC with DNA topoisomerase I inhibitor, exhibits promising safety profile and therapeutic efficacy in preclinical small cell lung cancer models.

BACKGROUND: Delta-like ligand 3 (DLL3) is highly expressed on the cell surface of small cell lung cancer (SCLC), one of the most lethal malignancies, but minimally or not in normal tissues, making it an attractive target for SCLC. However, none of the DLL3-targeting antibody-drug conjugates (ADCs) have been approved for SCLC therapy yet. We developed DB-1314, the new anti-DLL3 ADC composed of a novel humanized anti-DLL3 monoclonal antibody (DB131401) conjugated with eight molecules of P1021 (topoisomerase I inhibitor), and described its preclinical profiles. METHODS: The binding epitope for DB131401 and Rovalpituzumab was tested by biolayer interferometry. The binding affinity and specificity of DB-1314 to DLL3 and other homologous proteins were respectively measured by surface plasmon resonance and enzyme-linked immunosorbent assay. Internalization, bystander effects, and antibody-dependent cell-mediated cytotoxicity (ADCC) were assessed by respective assay. DLL3 was quantified by antibodies bound per cell assay and immunohistochemistry. In vitro and in vivo growth inhibition studies were evaluated in SCLC cell lines, and cell line/patient-derived xenograft models. The safety profile was measured in cynomolgus monkeys. RESULTS: DB-1314 induces potent, durable, and dose-dependent antitumor effects in cells in vitro and in cell/patient-derived xenograft models in vivo. The killing activity of DB-1314 mechanically arises from P1021-induced DNA damage, whereby P1021 is delivered and released within tumor cells through DLL3-specific binding and efficient internalization. Bystander effects and ADCC also contribute to the antitumor activity of DB-1314. DB-1314 displays favorable pharmacokinetic and toxicokinetic profiles in rats and cynomolgus monkeys; besides, DB-1314 is well-tolerated at a dose of up to 60 mg/kg in monkeys. CONCLUSIONS: These results suggest that DB-1314 may be a candidate ADC targeting DLL3 for the treatment of DLL3-positive SCLC, supporting further evaluation in the clinical setting.

Junctional adhesion molecule 3 is a potential therapeutic target for small cell lung carcinoma.

There are few effective therapies for small cell lung carcinoma (SCLC); thus, we need to develop novel and efficacious treatments. We hypothesized that an antibody-drug conjugate (ADC) could be a promising option for SCLC. Several publicly available databases were used to demonstrate the extent to which junctional adhesion molecule 3 (JAM3) mRNA was expressed in SCLC and lung adenocarcinoma cell lines and tissues. Three SCLC cell lines, Lu-135, SBC-5, and Lu-134 A, were selected and examined for JAM3 protein expression by flow cytometry. Finally, we examined the response of the three SCLC cell lines to a conjugate between an anti-JAM3 monoclonal antibody HSL156 (developed in-house) and the recombinant protein DT3C, which consists of diphtheria toxin lacking the receptor-binding domain but containing the C1, C2, and C3 domains of streptococcal protein G. In silico analyses revealed that JAM3 mRNA was expressed higher in SCLC cell lines and tissues than in those of lung adenocarcinoma. As expected, all the three SCLC cell lines examined were positive for JAM3 at the mRNA and protein levels. Consequently, control SCLC cells, but not JAM3-silenced ones, were highly sensitive to HSL156-DT3C conjugates, resulting in dose- and time-dependent decreased viability. Finally, silencing JAM3 alone suppressed the growth of all SCLC cell lines examined. Taken together, these findings suggest that an ADC targeting JAM3 could represent a new approach to treating SCLC patients.

A Newly Developed Anti-L1CAM Monoclonal Antibody Targets Small Cell Lung Carcinoma Cells.

Few effective treatments are available for small cell lung cancer (SCLC), indicating the need to explore new therapeutic options. Here, we focus on an antibody-drug conjugate (ADC) targeting the L1 cell adhesion molecule (L1CAM). Several publicly available databases reveal that (1) L1CAM is expressed at higher levels in SCLC cell lines and tissues than in those of lung adenocarcinoma and (2) the expression levels of L1CAM are slightly higher in SCLC tissues than in adjacent normal tissues. We conducted a series of in vitro experiments using an anti-L1CAM monoclonal antibody (termed HSL175, developed in-house) and the recombinant protein DT3C, which consists of diphtheria toxin lacking the receptor-binding domain but containing the C1, C2, and C3 domains of streptococcal protein G. Our HSL175-DT3C conjugates theoretically kill cells only when the conjugates are internalized by the target (L1CAM-positive) cells through antigen-antibody interaction. The conjugates (an ADC analog) were effective against two SCLC-N (NEUROD1 dominant) cell lines, Lu-135 and STC-1, resulting in decreased viability. In addition, L1CAM silencing rendered the two cell lines resistant to HSL175-DT3C conjugates. These findings suggest that an ADC consisting of a humanized monoclonal antibody based on HSL175 and a potent anticancer drug would be effective against SCLC-N cells.

Small Cell Lung Carcinoma Cells Depend on KIF11 for Survival.

Few efficacious treatment options are available for patients with small cell lung carcinoma (SCLC), indicating the need to develop novel therapeutic approaches. In this study, we explored kinesin family member 11 (KIF11), a potential therapeutic target in SCLC. An analysis of publicly available data suggested that KIF11 mRNA expression levels are significantly higher in SCLC tissues than in normal lung tissues. When KIF11 was targeted by RNA interference or a small-molecule inhibitor (SB743921) in two SCLC cell lines, Lu-135 and NCI-H69, cell cycle progression was arrested at the G2/M phase with complete growth suppression. Further work suggested that the two cell lines were more significantly affected when both KIF11 and BCL2L1, an anti-apoptotic BCL2 family member, were inhibited. This dual inhibition resulted in markedly decreased cell viability. These findings collectively indicate that SCLC cells are critically dependent on KIF11 activity for survival and/or proliferation, as well as that KIF11 inhibition could be a new strategy for SCLC treatment.

Small cell lung cancer: Novel treatments beyond immunotherapy.

Small cell lung cancer (SCLC) arises in peribronchial locations and infiltrates the bronchial submucosa, including about 15% of lung cancer cases. Despite decades of research, the prognosis for SCLC patients remains poor because this tumor is characterized by an exceptionally high proliferative rate, strong tendency for early widespread metastasis and acquired chemoresistance. Omics profiling revealed that SCLC harbor extensive chromosomal rearrangements and a very high mutation burden. This led to the development of immune-checkpoint inhibitors as single agents or in combination with chemotherapy, which however resulted in a prolonged benefit only for a small subset of patients. Thus, the present review discusses the rationale and limitations of immunotherapeutic approaches, presenting the current biological understanding of aberrant signaling pathways that might be exploited with new potential treatments. In particular, new agents targeting DNA damage repair, cell cycle checkpoint, and apoptosis pathways showed several promising results in different preclinical models. Epigenetic alterations, gene amplifications and mutations can act as biomarkers in this context. Future research and improved clinical outcome for SCLC patients will depend on the integration between these omics and pharmacological studies with clinical translational research, in order to identify specific predictive biomarkers that will be hopefully validated using clinical trials with biomarker-selected targeted treatments.

Identification of lncRNA, miRNA and mRNA expression profiles and ceRNA Networks in small cell lung cancer.

BACKGROUND: Small cell lung cancer (SCLC) is a highly lethal malignant tumor. It accounts for approximately 15% of newly diagnosed lung cancers. Long non-coding RNAs (lncRNAs) can regulate gene expression and contribute to tumorigenesis through interactions with microRNAs (miRNAs). However, there are only a few studies reporting the expression profiles of lncRNAs, miRNAs, and mRNAs in SCLC. Also, the role of differentially expressed lncRNAs, miRNAs, and mRNAs in relation to competitive endogenous RNAs (ceRNA) network in SCLC remain unclear. RESULTS: In the present study, we first performed next generation sequencing (NGS) with six pairs of SCLC tumors and adjacent non-cancerous tissues obtained from SCLC patients. Overall, 29 lncRNAs, 48 miRNAs, and 510 mRNAs were found to be differentially expressed in SCLC samples (|log2[fold change] |> 1; P < 0.05). Bioinformatics analysis was performed to predict and construct a lncRNA-miRNA-mRNA ceRNA network, which included 9 lncRNAs, 11 miRNAs, and 392 mRNAs. Four up-regulated lncRNAs and related mRNAs in the ceRNA regulatory pathways were selected and validated by quantitative PCR. In addition, we examined the role of the most upregulated lncRNA, TCONS_00020615, in SCLC cells. We found that TCONS_00020615 may regulate SCLC tumorigenesis through the TCONS_00020615-hsa-miR-26b-5p-TPD52 pathway. CONCLUSIONS: Our study provided the comprehensive analysis of the expression profiles of lncRNAs, miRNAs, and mRNAs of SCLC tumors and adjacent non-cancerous tissues. We constructed the ceRNA networks which may provide new evidence for the underlying regulatory mechanism of SCLC. We also found that the lncRNA TCONS_00020615 may regulate the carcinogenesis of SCLC.

Prognostic significance of visceral pleural invasion in patients with surgically resected small-cell lung cancer: a population-based study.

OBJECTIVE: Visceral pleural invasion is an adverse prognostic factor in non-small-cell lung cancer, but its value in small-cell lung cancer remains unclear. Thus, we investigated the prognostic impact of visceral pleural invasion in patients with surgically resected small-cell lung cancer. METHODS: We queried the Surveillance, Epidemiology and End Results Program database for patients diagnosed with stages I-III (excluding N3 and nodal metastasis cannot be evaluated (NX)) small-cell lung cancer from 2004 to 2016, who underwent surgery. To minimize unbalanced baseline characteristics between the visceral pleural invasion and non-visceral pleural invasion groups, one-to-one propensity score matching was employed. A Kaplan-Meier curve was used to compare the overall survival of the two cohorts. A Cox proportional hazards model was adopted to determine the impact of visceral pleural invasion on survival. RESULTS: Of the 1416 patients included, 372 (26.27%) presented with visceral pleural invasion. Patients with visceral pleural invasion showed significantly worse overall survival (P < 0.001) both before and after propensity score matching. Multivariable analysis indicated that visceral pleural invasion was an independent adverse factor affecting survival. Patients with visceral pleural invasion showed poorer overall survival (hazard ratio: 1.44; 95% confidence interval: 1.17-1.76; P < 0.001). Subgroup analyses revealed that the non-visceral pleural invasion group was associated with favourable overall survival in N0 patients (P = 0.003) but not in N1 or N2 patients (P = 0.774 and 0.248, respectively). Patients diagnosed at younger ages, females, lower N stage, resection with a lobectomy and adjuvant chemotherapy were associated with improved overall survival in the visceral pleural invasion group. CONCLUSIONS: Visceral pleural invasion was an indicator of a poor prognosis for small-cell lung cancer, especially in those with N0 disease. Adjuvant chemotherapy significantly improves patient outcomes for patients with visceral pleural invasion.

Inflammation-based prognostic scoring system for predicting the prognosis of advanced small cell lung cancer patients receiving anlotinib monotherapy.

BACKGROUND: According to the randomized multicenter phase II trial (ALTER1202), anlotinib has been approved as a third-line therapy for advanced small-cell lung cancer (SCLC). Some studies showed the predictive function of inflammatory markers, including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) in the different cancers treated with anti-vascular targeting drugs. However, none of the studies showed the roles of NLR, PLR, and LMR in SCLC patients receiving anlotinib. Thus, our objective was to establish a scoring system based on inflammation to individuate patient stratification and selection based on NLR, PLR, and LMR. METHODS: NLR, PLR, and LMR and their variations were calculated in 53 advanced SCLC patients receiving anlotinib as a third- or further-line treatment at Ningbo Medical Center Lihuili Hospital between January 2019 and December 2021. Kaplan-Meier curves were plotted. Both univariate and multivariate Cox regressions were used to identify predictors of survival. RESULTS: Disease control rate was related to pre-NLR, pre-PLR, pre-LMR, post-NLR elevation, post-PLR elevation, and post-LMR elevation. The multivariate analysis determined post-NLR elevation, pre-PLR > 240.56, and pre-LMR ≤1.61 to be independently associated with progression-free survival, not overall survival. The inflammation-based prognostic scoring system demonstrated favorable predictive ability from the receiver operating characteristic curve (AUC: 0.791, 95% CI: 0.645-0.938). CONCLUSIONS: Post-NLR variation, pre-PLR, and pre-LMR were independent prognostic factors for PFS in advanced SCLC receiving anlotinib monotherapy. The inflammation-based prognostic scoring system can accurately predict effectiveness and survival.

Aberrant methylation modifications reflect specific drug responses in small cell lung cancer.

In the study, Methylated DNA immunoprecipitation sequencing, RNA sequencing, and whole-exome sequencing were employed to clinical small cell lung cancer (SCLC) patients. Then, we verified the therapeutic predictive effects of differentially methylated genes (DMGs) in 62 SCLC cell lines. Of 4552 DMGs between chemo-sensitive and chemo-insensitive group, coding genes constituted the largest percentage (85.08%), followed by lncRNAs (10.52%) and miRNAs (3.56%). Both two groups demonstrated two methylation peaks near transcription start site and transcription end site. Two lncRNA-miRNA-mRNA networks suggested the extensive genome connection between chemotherapy efficacy-related non-coding RNAs (ncRNAs) and mRNAs. Combing miRNAs and lncRNAs could effectively predict chemotherapy response in SCLC. In addition, we also verified the predictive values of mutated genes in SCLC cell lines. This study was the first to evaluate multiple drugs efficacy-related ncRNAs and mRNAs which were modified by methylation in SCLC. DMGs identified in our research might serve as promising therapeutic targets to reverse drugs-insensitivity by complex lncRNA-miRNA-mRNA mechanisms in SCLC.

Trilaciclib prior to chemotherapy and atezolizumab in patients with newly diagnosed extensive-stage small cell lung cancer: A multicentre, randomised, double-blind, placebo-controlled Phase II trial.

Trilaciclib is an intravenous CDK4/6 inhibitor administered prior to chemotherapy to preserve haematopoietic stem and progenitor cells and immune system function from chemotherapy-induced damage (myelopreservation). The effects of administering trilaciclib prior to carboplatin, etoposide and atezolizumab (E/P/A) were evaluated in a randomised, double-blind, placebo-controlled Phase II study in patients with newly diagnosed extensive-stage small cell lung cancer (ES-SCLC) (NCT03041311). The primary endpoints were duration of severe neutropenia (SN; defined as absolute neutrophil count <0.5 × 109 cells per L) in Cycle 1 and occurrence of SN during the treatment period. Other endpoints were prespecified to assess the effects of trilaciclib on additional measures of myelopreservation, patient-reported outcomes, antitumour efficacy and safety. Fifty-two patients received trilaciclib prior to E/P/A and 53 patients received placebo. Compared to placebo, administration of trilaciclib resulted in statistically significant decreases in the mean duration of SN in Cycle 1 (0 vs 4 days; P < .0001) and occurrence of SN (1.9% vs 49.1%; P < .0001), with additional improvements in red blood cell and platelet measures and health-related quality of life (HRQoL). Trilaciclib was well tolerated, with fewer grade ≥3 adverse events compared with placebo, primarily due to less high-grade haematological toxicity. Antitumour efficacy outcomes were comparable. Administration of trilaciclib vs placebo generated more newly expanded peripheral T-cell clones (P = .019), with significantly greater expansion among patients with an antitumour response to E/P/A (P = .002). Compared with placebo, trilaciclib administered prior to E/P/A improved patients' experience of receiving treatment for ES-SCLC, as shown by reduced myelosuppression, and improved HRQoL and safety profiles.

ARHGEF19 regulates MAPK/ERK signaling and promotes the progression of small cell lung cancer.

Small cell lung cancer (SCLC) is an aggressive lung tumor subtype with poor survival. To identify genes that differentially expressed in SCLC with tumor promotion activity as candidate therapeutic targets, we analyzed the expression of 50 RhoGEFs family genes in published microarray data of SCLC and normal tissues (Gene Expression Omnibus (GEO) dataset GSE43346). We identified ARHGEF19, a member of RhoGEFs family, as an overexpressed oncogene in SCLC. ARHGEF19 is up-regulated in SCLC tissues and ranks first in RhoGEFs family genes. Enforced ARHGEF19 expression promotes SCLC cell proliferation in vitro and its knockdown decreases cell proliferation in vitro and in vivo. ARHGEF19-DH and -PD domain interacts with HRAS and activates the MAPK/ERK pathway in SCLC cells and SCLC xenografts. Our study presents evidences that ARHGEF19 overexpression promotes SCLC cell growth and activates the MAPK/ERK pathway. These findings would shed light on the development of new therapeutics for SCLC management.

History of Japan Clinical Oncology Group (JCOG) Lung Cancer Study Group.

The Japan Clinical Oncology Group Lung Cancer Study Group has been carrying out clinical studies, exploring new strategies of treatment, supportive therapies (antiemetics, etc.), etc., for a variety of cancers, including not only small cell lung cancer and non-small cell lung cancer but also rare chest tumours (represented by thymoma) and cancer-associated conditions (cancerous pericarditis, cancerous pleuritis, etc.). In this review, an overview of all studies conducted from 1985 to 2019 is provided.

Advances and challenges in immunotherapy of small cell lung cancer.

Small cell lung cancer (SCLC) is a highly lethal disease, characterized by early metastasis and rapid growth, and no effective treatment after relapse. Etoposide-platinum (EP) combination has been the backbone therapy of SCLC over the past 30 years. It is extremely urgent and important to seek new therapies for SCLC. In the past 5 years, immunotherapy, such as immune checkpoint inhibitors programmed cell death protein-1 (PD-1), cytotoxic T lymphocyte associatedprotein-4 (CTLA-4), has made remarkable achievements in the treatment of patients with SCLC, and it has become the first-line option for the treatment of some patients. Some traditional chemotherapeutic drugs or targeted drugs, such as alkylating agent temozolomide and transcription inhibitor lurbinectedin, have been found to have immunomodulatory effects and are expected to become new immunotherapeutic agents. In this study, we aimed to review the efficacy of new treatments for SCLC and discuss the current challenges and application prospect in the treatment of SCLC patients.

Prognostic significance of neutrophil/lymphocyte ratio (NLR) and correlation with PET-CT metabolic parameters in small cell lung cancer (SCLC).

PURPOSE: The aim of this study is to detect the prognostic significance of neutrophil/lymphocyte ratio (NLR) in SCLC and to evaluate the relation with 18F-FDG PET-CT metabolic parameters (PET-CT MPs). METHODS: Demographic parameters, laboratory values including NLR and other clinical variables were analyzed in 112 patients with small cell lung cancer (SCLC) and 54 of these patients had results of metabolic parameters detected with 18 FDG PET-CT [including SUVmax, SUVmean, metabolic tumor volume (MTV), whole body MTV (WBMTV), TLG (total lesion glycolysis), whole body TLG (WBTLG)] were evaluated for survival analyses. RESULTS: Mean and median overall survival (OS) and progression-free survival (PFS) were found to be significantly longer in cases with NLR < 4 compared with NLR > 4 in totally. Also stage, performance status, response to first-line therapy, LDH, and lymphocyte count were found to be prognostic for OS and PFS. MTV, WBMTV and WBTLG were found to be prognostic for both OS and PFS, while SUVmax found to be significant for OS. Patients with NLR ≥ 4, MTV ≥ 60.1, WBMTV ≥ 120 and WBTLG ≥ 1000 points had lower OS and PFS. A moderate positive correlation was found between NLR and SUVmean (r: 0.36), SUVmax (r: 0.34), TLG (r: 0.39), MTV (r: 0.51), WBMTV (r: 0.40), and WBTLG (r: 0.46). CONCLUSION: There is relationship between PET-CT metabolic parameters and NLR in SCLC. Highest correlation was found with NLR and MTV, WBMTV, and WBTLG, and evaluation of NLR together with these parameters predicts survival times and tumor biology more clearly in SCLC.

A long non-coding RNA HOTTIP expression is associated with disease progression and predicts outcome in small cell lung cancer patients.

BACKGROUND: Despite progress in treatment of small cell lung cancer (SCLC), the biology of the tumor still remains poorly understood. Recently, we globally investigated the contributions of lncRNA in SCLC with a special focus on sponge regulatory network. Here we report lncRNA HOTTIP, which is specifically amplified in SCLC, is associated with SCLC proliferation and poor prognosis of patients. METHODS: RT-qPCR was used to investigate the expression of HOTTIP in SCLC tissues and cell lines. The role of HOTTIP in SCLC cell proliferation was demonstrated by CCK8 assay, colony formation assay, flow cytometry analysis and in vivo SCLC xenograft model in nude mice through HOTTIP loss- and gain-of-function effects. Western blot assay was used to evaluate gene expression in cell lines at protein level. RNA pull-down, Mass spectrometry and RNA binding protein immunoprecipitation (RIP) were performed to confirm the molecular mechanism of HOTTIP involved in SCLC progression. RESULTS: We found that HOTTIP was overexpressed in SCLC tissues, and its expression was correlated with the clinical stage and the shorter survival time of SCLC patients. Moreover, HOTTIP knockdown could impair cell proliferation, affect the cell cycle and inhibit tumor growth of mice, while HOTTIP overexpression might enhance cell proliferation and cell cycle in vitro and in vivo. Mechanistic investigations showed that HOTTIP functions as an oncogene in SCLC progression by sponging miR-574-5p and affecting the expression of polycomb group protein EZH1. CONCLUSIONS: Overall, we identified that HOTTIP was involved in SCLC tumorigenesis through the ceRNA network "HOTTIP/miR-574-5p/EZH1". Our findings not only illuminate how HOTTIP confers an oncogenic function in SCLC pathogenesis, but also underscore a novel gene expression governing hallmarks in the disease.

Long non-coding RNA TUG1 is involved in cell growth and chemoresistance of small cell lung cancer by regulating LIMK2b via EZH2.

BACKGROUND: Taurine upregulated gene1 (TUG1) as a 7.1-kb lncRNA, has been shown to play an oncogenic role in various cancers. However, the biological functions of lncRNA TUG1 in small cell lung cancer (SCLC) remain unknown. The aim of this study is to explore the roles of TUG1 in cell growth and chemoresistance of SCLC and its possible molecular mechanism. METHODS: The expression of TUG1 in thirty-three cases of SCLC tissues and SCLC cell line were examined by quantitative RT-PCR (qRT-PCR). The functional roles of TUG1 in SCLC were demonstrated by CCK8 assay, colony formation assay, wound healing assay and transwell assay, flow cytometry analysis and in vivo study through siRNA or shRNA mediated knockdown. Western blot assays were used to evaluate gene and protein expression in cell lines. Chromatin immunoprecipitation (ChIP) and RNA binding protein immunoprecipitation (RIP) were performed to confirm the molecular mechanism of TUG1 involved in cell growth and chemoresistance of small cell lung cancer. RESULTS: We found that TUG1 was overexpressed in SCLC tissues, and its expression was correlated with the clinical stage and the shorter survival time of SCLC patients. Moreover, downregulation of TUG1 expression could impair cell proliferation and increased cell sensitivity to anticancer drugs both in vitro and in vivo. We also discovered that TUG1 knockdown significantly promoted cell apoptosis and cell cycle arrest, and inhibited cell migration and invasion in vitro . We further demonstrated that TUG1 can regulate the expression of LIMK2b (a splice variant of LIM-kinase 2) via binding with enhancer of zeste homolog 2 (EZH2), and then promoted cell growth and chemoresistance of SCLC. CONCLUSIONS: Together, these results suggested that TUG1 mediates cell growth and chemoresistance of SCLC by regulating LIMK2b via EZH2.

Nephrotic Syndrome in Small Cell Lung Cancer and Induction of C-Mip in Podocytes.

Paraneoplastic nephrotic syndrome is often a complication in patients with cancer, and various histologic lesions have been described in the kidney. We report the case of a 76-year-old woman who presented with a podocytopathy that was found to be associated with a small cell lung carcinoma (SCLC). One cycle of carboplatin-etoposide combination therapy led to resolution of nephrotic syndrome and remission of the lung carcinoma. C-Maf-inducing protein (C-Mip) was overexpressed in both podocytes and cancer cells, but was not found in control kidney and lung tissue samples. C-Mip also was absent in SCLC cells from 30 patients without nephrotic syndrome. Exposing cultured podocytes to a sample of our patient's serum that was collected prior to chemotherapy led to disorganization of the podocyte cytoskeleton and induction of C-Mip expression, which was not observed with control serum or our patient's serum sampled after chemotherapy. These observations suggest that C-Mip may play an important role in SCLC-related podocytopathy and that a circulating factor likely induces its expression in the kidney.

Trends, predictors, and impact of systemic chemotherapy in small cell lung cancer patients between 1985 and 2005.

BACKGROUND: The last 3 decades have witnessed limited therapeutic advances in small cell lung cancer (SCLC) management. This study evaluated real-world trends in the use of systemic therapies and the impact on patient outcomes in the United States. METHODS: The Surveillance, Epidemiology, and End Results-Medicare database was used to find patients diagnosed with SCLC between 1985 and 2005. The 1985-1990 period served as the baseline for a temporal analysis conducted at 5-year intervals (1985-1990, 1991-1995, 1996-2000, and 2001-2005). Cox proportional models were used to estimate the effect of chemotherapy on survival. Results were validated with a propensity-matched analysis. RESULTS: There were 47,351 eligible patients: 52% were male; the median age was 71 years; and 87% were white, 7% were black, and 1.4% were Asian. The proportion of patients treated with chemotherapy was low but increased over time (38%, 55%, 50%, and 53%; P < .001). Race, diagnosis period, age, stage, and location of residence significantly predicted chemotherapy use. Females (51%), Asians (53%), and rural residents (60%) were more likely to receive chemotherapy. The median overall survival with and without chemotherapy was 9.6 and 3.6 months, respectively. Linear trend analyses showed a modest reduction in the impact of chemotherapy on survival for patients treated with chemotherapy versus untreated patients (hazard ratios [HRs], 0.59, 0.61, 0.64, and 0.62; P < .001) but an overall trend of improved survival for treated (HRs, 1.0, 1.03, 1.00, and 0.96; P = .005) and untreated patients (HRs, 1.0, 0.99, 0.94, and 0.92; P < .001). There was no survival difference between patients treated with carboplatin and patients treated with cisplatin (HR, 0.99; confidence interval [CI], 0.81-1.19; P = .875). Additional therapy beyond platinum-based chemotherapy was associated with a survival benefit (HR, 0.78; CI, 0.75-0.81; P < .001). CONCLUSIONS: Chemotherapy use was associated with a survival benefit in Medicare patients with SCLC treated in a real-world setting.

EPHA3 regulates the multidrug resistance of small cell lung cancer via the PI3K/BMX/STAT3 signaling pathway.

Multidrug resistance (MDR) is a major obstacle to the treatment of small cell lung cancer (SCLC). EPHA3 has been revealed to be the most frequently mutated Eph receptor gene in lung cancer with abnormal expression. Growing evidence indicates that the signaling proteins of EPHA3 downstream, including PI3K, BMX and STAT3, play crucial roles in tumorigenesis and cancer progression. To explore the possible role of EPHA3 in MDR, we assessed the influence of EPHA3 on chemoresistance, cell cycle, apoptosis, and tumor growth, as well as the relationship between EPHA3 and the expression of PI3K, BMX, and STAT3 in SCLC. We observed that overexpression of EPHA3 in SCLC cells decreased chemoresistance by increasing apoptosis and inducing G0/G1 arrest, accompanied by reduced phosphorylation of PI3K/BMX/STAT3 signaling pathway. Knockdown of EPHA3 expression generated a resistant phenotype of SCLC, as a result of decreased apoptosis and induced G2/M phase arrest. And re-expression of EPHA3 in these cells reversed the resistant phenotype. Meanwhile, increased phosphorylation of PI3K/BMX/STAT3 signaling pathway was observed in these cells with EPHA3 deficiency. Notably, both PI3K inhibitor (LY294002) and BMX inhibitor (LFM-A13) impaired the chemoresistance enhanced by EPHA3 deficiency in SCLC cell lines. Furthermore, EPHA3 inhibited growth of SCLC cells in vivo and was correlated with longer overall survival of SCLC patients. Thus, we first provide the evidences that EPHA3 is involved in regulating the MDR of SCLC via PI3K/BMX/STAT3 signaling and may be a new therapeutic target in SCLC.

Amifampridine phosphate (Firdapse(®)) is effective and safe in a phase 3 clinical trial in LEMS.

OBJECTIVE: We evaluated the efficacy and safety of amifampridine phosphate (Firdapse(®)) for symptomatic treatment in Lambert-Eaton myasthenic syndrome (LEMS). METHODS: Phase 3, randomized, double-blind, study. Patients were treated initially with amifampridine phosphate for 7-91 days, followed by randomization to continue amifampridine phosphate for 14 days or placebo (7-day taper, 7-day placebo). The primary efficacy endpoints were changes from baseline at day 14 in Quantitative Myasthenia Gravis and Subject Global Impression scores. RESULTS: The coprimary efficacy end points and 1 of the secondary efficacy end points were met, showing a significant benefit of aminfampridine phosphate over placebo at Day 14. All 5 primary, secondary, and tertiary endpoints achieved statistical significance at Day 8. Amifampridine phosphate was well tolerated; the most common adverse events were oral and digital paresthesias, nausea, and headache. CONCLUSIONS: This study provides Class I evidence of efficacy of amifampridine phosphate as a symptomatic treatment for LEMS.