Pembrolizumab After Two or More Lines of Previous Therapy in Patients With Recurrent or Metastatic SCLC: Results From the KEYNOTE-028 and KEYNOTE-158 Studies

Facts and Hopes on Cancer Immunotherapy for Small Cell Lung Cancer

Platinum-based chemotherapy plus PD1 axis blockade is the standard of care in the first-line treatment of extensive-stage small cell lung cancer (SCLC). Despite the robust and consistent increase in long-term survival with PD1 axis inhibition, the magnitude of the benefit from immunotherapy seems lower than that for other solid tumors. Several immune evasive mechanisms have been shown to be prominently altered in human SCLC, including T-cell exclusion, downregulation of components of the MHC class I antigen processing and presentation machinery, or upregulation of macrophage inhibitory checkpoints, among others. New immunotherapies aiming to target some of these dominant immune suppressive features are being intensively evaluated preclinically and clinically in SCLC. They include strategies to enhance the efficacy and/or reverse features that promote intrinsic resistance to PD1 axis inhibition (e.g., restoring MHC class I deficiency and targeting DNA damage response) and novel immunomodulatory agents beyond T-cell checkpoint blockers (e.g., T cell-redirecting strategies, antibody-drug conjugates, or macrophage checkpoint blockers). Among them, delta-like ligand 3-targeted bispecific T-cell engagers have shown the most compelling preliminary evidence of clinical efficacy and hold promise as therapies that might contribute to further improve patient outcomes in this disease. In this study, we first provide a brief overview of key tumor microenvironment features of human SCLC. Then, we update the current clinical evidence with immune checkpoint blockade and review other emerging immunotherapy strategies that are gaining increasing attention in SCLC. We finally summarize our future perspective on immunotherapy and precision oncology for this disease.

Circulating tumor cells: advancing personalized therapy in small cell lung cancer patients

Small cell lung cancer (SCLC) is a highly aggressive cancer with a dismal 5-year survival of < 7%, despite the addition of immunotherapy to first-line chemotherapy. Specific tumor biomarkers, such as delta-like ligand 3 (DLL3) and schlafen11 (SLFN11), may enable the selection of more efficacious, novel immunomodulating targeted treatments like bispecific T-cell engaging monoclonal antibodies (tarlatamab) and chemotherapy with PARP inhibitors. However, obtaining a tissue biopsy sample can be challenging in SCLC. Circulating tumor cells (CTCs) have the potential to provide molecular insights into a patient's cancer through a "simple" blood test. CTCs have been studied for their prognostic ability in SCLC; however, their value in guiding treatment decisions is yet to be elucidated. This review explores novel and promising targeted therapies in SCLC, summarizes current knowledge of CTCs in SCLC, and discusses how CTCs can be utilized for precision medicine.

Extensive-stage small-cell lung cancer in patients receiving atezolizumab plus carboplatin-etoposide: stratification of outcome based on a composite score that combines gene expression profiling and immune characterization of microenvironment

PURPOSE

Small-cell lung cancer (SCLC) is an aggressive disease with a dismal prognosis. The addition of immune checkpoints inhibitors to standard platinum-based chemotherapy in first-line setting achieves a durable benefit only in a patient subgroup. Thus, the identification of predictive biomarkers is an urgent unmet medical need.

EXPERIMENTAL DESIGN

Tumor samples from naive extensive-stage (ES) SCLC patients receiving atezolizumab plus carboplatin-etoposide were analyzed by gene expression profiling and two 9-color multiplex immunofluorescence panels, to characterize the immune infiltrate and SCLC subtypes. Associations of tissue biomarkers with time-to-treatment failure (TTF), progression-free survival (PFS) and overall survival (OS), were assessed.

RESULTS

42 patients were included. Higher expression of exhausted CD8-related genes was independently associated with a longer TTF and PFS while increased density of B lymphocytes correlated with longer TTF and OS. Higher percentage of M2-like macrophages close to tumor cells and of CD8+T cells close to CD4+T lymphocytes correlated with increased risk of TF and longer survival, respectively. A lower risk of TF, disease progression and death was associated with a higher density of ASCL1+tumor cells while the expression of POU2F3 correlated with a shorter survival. A composite score combining the expression of exhausted CD8-related genes, B lymphocyte density, ASCL1 tumor expression and quantification of CD163+macrophages close to tumor cells, was able to stratify patients into high-risk and low-risk groups.

CONCLUSIONS

In conclusion, we identified tissue biomarkers and a combined score that can predict a higher benefit from chemoimmunotherapy in ES-SCLC patients.

Serum albumin and derived neutrophil-to-lymphocyte ratio are potential predictive biomarkers for immune checkpoint inhibitors in small cell lung cancer

Background

Immune checkpoint inhibitors (ICIs) have reshaped the treatment landscape of small cell lung cancer (SCLC), but only a minority of patients benefit from this therapy. Therefore, it is critical to identify potential risk factors that could predict the efficacy of ICI treatment in SCLC patients and identify patient subgroups who may benefit the most from ICI therapy.

Methods

Our study included a total of 183 SCLC patients who had received at least one dose of ICI treatment. We utilized both logistic regression and Cox proportional hazard regression to evaluate whether various patient clinical factors and serum biomarkers could serve as predictors of patient response to treatment and overall survival (OS) during ICI therapy.

Results

Logistic regression showed that patients with a history of surgery (p=0.003, OR 9.06, 95% CI: (2.17, 37.9)) and no metastasis (p=0.008, OR 7.82, 95% CI: (1.73, 35.4)) exhibited a higher odds of response to ICI treatment. Cox regression analyses demonstrated that pretreatment blood albumin (p=0.003, HR 1.72, 95% CI: (1.21, 2.45)) and derived neutrophil to lymphocyte ratio (dNLR) (p=0.003, HR 1.71, 95% CI: (1.20-2.44)) were independent predictors for OS in SCLC patients. By establishing a pre-treatment prognostic scoring system based on baseline albumin and dNLR, we found that patients with high albumin and low dNLR exhibited a significantly better prognosis than those with low albumin and high dNLR in both the full (P<.0001, HR 0.33, 95% CI: 0.20-0.55) and the metastatic cohort (P<.0001, HR 0.28, 95% CI: 0.15-0.51). The better prognostic group also had younger age, higher BMI and lower systemic inflammatory biomarker values than the unfavorable group (P<.0001).

Conclusion

Our data reveals the significant role of metastasis status and treatment history in predicting the initial response of SCLC patients to ICI treatment. However, baseline serum albumin and dNLR provide a more precise prognostic prediction for patient OS. The scoring system based on albumin and dNLR enhances the ability to stratify patient prognosis and holds the potential to guide clinical decision-making for SCLC patients undergoing ICI therapy.

N-glycan signatures identified in the serum from biliary tract cancer patients: Association with clinical diagnosis and prognosis

BACKGROUND

Changes in the expression of genes related to glycosyltransferases may lead to alterations in N-glycan structure abundance, potentially acting as markers for diagnosis and prognosis in biliary tract cancer (BTC).

METHODS

This study was divided into cross-sectional and longitudinal approaches. The cross-sectional study included 316 BTC and 301 non-BTC. Propensity score matching was applied to adjust for sex and age differences between BTC and non-BTC. Univariate and multivariate logistic regression identified independent risk factors for BTC and constructed the BTC-G model. The ROC curve was used to validate the diagnostic performance of BTC-G. Longitudinal follow-up studies included postoperative (N = 50) and immunotherapy (N = 43) follow-up cohorts. Cox regression analysis identified N-glycan structures impacting BTC prognosis postoperative and immunotherapy, with further confirmation through Kaplan-Meier curves.

RESULTS

Univariate and multivariate analyses identified Peak3 (OR: 0.790, 95% CI: 0.658-0.949), Peak9 (OR: 1.646, 95% CI: 1.409-1.922), and Peak9p (OR: 2.467, 95% CI: 1.267-4.804) as independent BTC risk factors, leading to the creation of the BTC-G. The ROC curve confirmed that BTC-G performed well in training (AUC: 0.753, 95% CI: 0.703-0.799), validation (AUC: 0.811, 95% CI: 0.740-0.870), and CA19-9 negative cohorts (AUC: 0.717, 95% CI: 0.664-0.767). Cox regression analysis and Kaplan-Meier curves established that Peak12 (HR: 5.578, 95% CI: 1.145-27.170) and Peak11 (HR: 1.104, 95% CI: 0.611-1.994) are independent risk factors for BTC prognosis following surgery and immunotherapy, respectively.

CONCLUSIONS

Our NGFP technology supplements BTC diagnostics, distinguishing survival and recurrence subtypes for postoperative and immunotherapy, thereby supporting the development of treatment strategies.

Beyond monotherapy: An era ushering in combinations of PARP inhibitors with immune checkpoint inhibitors for solid tumors

The introduction of PARP inhibitors (PARPis) and immune checkpoint inhibitors (ICIs) has marked a significant shift in the treatment landscape for solid tumors. Emerging preclinical evidence and initial clinical trials have indicated that the synergistic application of PARPis and ICIs may enhance treatment efficacy and potentially improve long-term patient outcomes. Nonetheless, how to identify specific tumor types and molecular subgroups most likely to benefit from this combination remains an area of ongoing research. This review thoroughly examines current studies on the co-administration of PARPis and ICIs across various solid tumors. It explores the underlying mechanisms of action, evaluates clinical efficacy, identifies potential responder populations, and delineates common adverse events alongside strategic management approaches. The aim is to offer a detailed understanding of this combination therapy, potentially guiding future therapeutic strategies for solid tumors.

Oncology's trial and error: Analysis of the FDA withdrawn accelerated approvals

Launched in 1992, the FDA accelerated approval program grants drugs indicated in rare/life threatening diseases the ability to be marketed at a faster pace than through the traditional track. Each manufacturing company presents its drug to the FDA, and within 60 days it will determine if the drug is eligible for this path. Many drugs that were initially approved through this route, subsequently did not demonstrate their clinical benefits. With cancer being a leading cause of death, a vast majority of drugs that have been approved/withdrawn from this pathway are indicated within oncology. There are a wide variety of cancer subtypes and therapeutic target sites that these drugs have been evaluated for. Herein, is an overview of the 17 oncology drugs, spanning 22 cancer-related indications, that had been approved within the accelerated route and subsequently withdrawn.

The Evolving Scenario of ES-SCLC Management: From Biology to New Cancer Therapeutics

Small cell lung cancer (SCLC) is an aggressive neuroendocrine carcinoma accounting for 15% of lung cancers with dismal survival outcomes. Minimal changes in therapy and prognosis have occurred in SCLC for the past four decades. Recent progress in the treatment of extensive-stage disease (ES-SCLC) has been marked by incorporating immune checkpoint inhibitors (ICIs) into platinum-based chemotherapy, leading to modest improvements. Moreover, few second-line-and-beyond treatment options are currently available. The main limitation for the molecular study of SCLC has been the scarcity of samples, because only very early diseases are treated with surgery and biopsies are not performed when the disease progresses. Despite all these difficulties, in recent years we have come to understand that SCLC is not a homogeneous disease. At the molecular level, in addition to the universal loss of retinoblastoma (RB) and TP53 genes, a recent large molecular study has identified other mutations that could serve as targets for therapy development or patient selection. In recent years, there has also been the identification of new genetic subtypes which have shown us how intertumor heterogeneity exists. Moreover, SCLC can also develop intratumoral heterogeneity linked mainly to the concept of cellular plasticity, mostly due to the development of resistance to therapies. The aim of this review is to quickly present the current standard of care of ES-SCLC, to focus on the molecular landscapes and subtypes of SCLC, subsequently present the most promising therapeutic strategies under investigation, and finally recap the future directions of ongoing clinical trials for this aggressive disease which still remains a challenge.

DRG2 is required for surface localization of PD-L1 and the efficacy of anti-PD-1 therapy

More than half of tumor patients with high PD-L1 expression do not respond to anti-PD-1/PD-L1 therapy, and the underlying mechanisms are yet to be clarified. Here we show that developmentally regulated GTP-binding protein 2 (DRG2) is required for response of PD-L1-expressing tumors to anti-PD-1 therapy. DRG2 depletion enhanced IFN-γ signaling and increased the PD-L1 level in melanoma cells. However, it inhibited recycling of endosomal PD-L1 and reduced surface PD-L1 levels, which led to defects in interaction with PD-1. Anti-PD-1 did not expand effector-like T cells within DRG2-depleted tumors and failed to improve the survival of DRG2-depleted tumor-bearing mice. Cohort analysis revealed that patients bearing melanoma with low DRG2 protein levels were resistant to anti-PD-1 therapy. These findings identify DRG2 as a key regulator of recycling of endosomal PD-L1 and response to anti-PD-1 therapy and provide insights into how to increase the correlation between PD-L1 expression and response to anti-PD-1 therapy.

Challenges and opportunities in the immunotherapy era: balancing expectations with hope in small-cell lung cancer

Small-cell lung cancer (SCLC) is a biologically aggressive subtype of lung cancer, a lethal disease characterized by rapid tumor growth, early relapse, a strong tendency for early widespread metastasis, and high genomic instability, making it a formidable foe in modern oncology practice. While the management of non-SCLC has been revolutionized in the era of immunotherapy, progress in SCLC has been more muted. Recent randomized phase III clinical trials have combined programmed death ligand-1 inhibitors to a chemotherapy backbone and demonstrated improved survival; however, the absolute benefit observed is short months. There is an undeniable urgent need for better responses, better agents, novel therapeutic approaches, and more rational, biomarker-driven clinical trials in SCLC. In this review, we discuss the rationale and current understanding of the biology of SCLC in the modern era of immunotherapy, discuss recent advances in front-line immunotherapeutic approaches that have changed clinical practice globally, provide an overview of some of the challenges and limitations that have staggered immune checkpoint blockade in SCLC, and explore some of the novel immunotherapeutic approaches currently being investigated.

Neoantigen Identification and Dendritic Cell-Based Vaccines for Lung Cancer Immunotherapy

Immunotherapies can treat many cancers, including difficult-to-treat cases such as lung cancer. Due to its tolerability, long-lasting therapeutic responses, and efficacy in a wide spectrum of patients, immunotherapy can also help to treat lung cancer, which has few treatment choices. Tumor-specific antigens (TSAs) for cancer vaccinations and T-cell therapies are difficult to discover. Neoantigens (NeoAgs) from genetic mutations, irregular RNA splicing, protein changes, or viral genetic sequences in tumor cells provide a solution. NeoAgs, unlike TSAs, are non-self and can cause an immunological response. Next-generation sequencing (NGS) and bioinformatics can swiftly detect and forecast tumor-specific NeoAgs. Highly immunogenic NeoAgs provide personalized or generalized cancer immunotherapies. Dendritic cells (DCs), which originate and regulate T-cell responses, are widely studied potential immunotherapeutic therapies for lung cancer and other cancers. DC vaccines are stable, reliable, and safe in clinical trials. The purpose of this article is to evaluate the current status, limitations, and prospective clinical applications of DC vaccines, as well as the identification and selection of major histocompatibility complex (MHC) class I and II genes for NeoAgs. Our goal is to explain DC biology and activate DC manipulation to help researchers create extremely potent cancer vaccines for patients.

Counterproductive effects of anti-CD38 and checkpoint inhibitor for the treatment of NK/T cell lymphoma

Introduction

Natural killer/T cell lymphoma (NKTL) is an aggressive malignancy associated with poor prognosis. This is largely due to limited treatment options, especially for relapsed patients. Immunotherapies like immune checkpoint inhibitors (ICI) and anti-CD38 therapies have shown promising but variable clinical efficacies. Combining these therapies has been suggested to enhance efficacy.

Methods

We conducted a case study on a relapsed NKTL patient treated sequentially with anti-CD38 followed by ICI (anti-PD1) using cytometry analyses.

Results and Discussion

Our analysis showed an expected depletion of peripheral CD38+ B cells following anti-CD38 treatment. Further analysis indicated that circulating anti-CD38 retained their function for up to 13 weeks post-administration. Anti-PD1 treatment triggered re-activation and upregulation of CD38 on the T cells. Consequently, these anti-PD1-activated T cells were depleted by residual circulating anti-CD38, rendering the ICI treatment ineffective. Finally, a meta-analysis confirmed this counterproductive effect, showing a reduced efficacy in patients undergoing combination therapy. In conclusion, our findings demonstrate that sequential anti-CD38 followed by anti-PD1 therapy leads to a counterproductive outcome in NKTL patients. This suggests that the treatment sequence is antithetic and warrants re-evaluation for optimizing cancer immunotherapy strategies.

Sintilimab plus anlotinib as second or further-line therapy for extensive disease small cell lung cancer: a phase 2 investigator-initiated non-randomized controlled trial

Background

Treatment options remain rather limited for extensive disease small cell lung cancer (ED-SCLC) patients in second or further-line setting.

Methods

The phase 2 investigator-initiated non-randomized study enrolled patients who had disease progression on at least one line of platinum-based chemotherapy. Participants received intravenous sintilimab 200 mg on day one and oral daily anlotinib 12 mg on days 1-14 once every three weeks per cycle. The primary endpoint was progression-free survival (PFS). The secondary endpoints included overall survival (OS), objective response rate (ORR), disease control rate (DCR) and safety. This study is registered with ClinicalTrials.gov (NCT04055792).

Findings

Forty-two patients were enrolled between August 29, 2019 and December 26, 2021 at Henan Cancer Hospital in China. 37 patients were evaluable for efficacy. The median follow-up was 24.8 months (IQR: 16.9-28.2). The median PFS was 6.1 months (95% CI: 5.0-7.3). The OS was 12.7 months (95% CI: 7.1-18.2). The ORR was 56.8% (21/37, 95% CI: 40.0-73.5) and the DCR was 89.2% (33/37, 95% CI: 78.7-99.7). Forty patients (40/42, 95%) had at least one treatment-related adverse event (TRAE). Immune-related adverse events (irAEs) were reported in 39 patients (39/42, 93%), while grade 3 or higher irAEs occurred in 11 patients (11/42, 26%). The most frequent irAEs were hypothyroidism (16/42, 38%), elevated gamma-glutamyl transpeptidase (15/42, 36%) and elevated creatine kinase MB (15/42, 36%). The most frequent grade 3 or higher irAEs were elevated gamma-glutamyl transpeptidase (5/42, 12%) and increased aspartate aminotransferase (3/42, 7%).

Interpretation

Sintilimab plus anlotinib demonstrated promising antitumor activities as second or further-line therapy for ED-SCLC and had manageable toxicities. The findings support further randomized controlled trials of this combination regimen for ED-SCLC.

Funding

Henan Province Health and Youth Subject Leader Training Project, Henan Health Science and Technology Innovation Talents, ZHONGYUAN QIANREN JIHUA, Henan International Joint Laboratory of drug resistance and reversal of targeted therapy for lung cancer, Tumor Research Fund of Anti-Angiogenesis Targeted Therapy of China Anti-Cancer Association.

Expression patterns and clinical implications of PDL1 and DLL3 biomarkers in small cell lung cancer retrospectively studied: Insights for therapeutic strategies and survival prediction

Lung cancer is a leading cause of cancer-related deaths globally, includes small cell lung cancer (SCLC), characterized by its aggressive nature and advanced disease at diagnosis. However, the identification of reliable biomarkers for SCLC has proven challenging, as no consistent predictive biomarker has been established. Nonetheless, certain tumor-associated antigens, including programmed death-ligand 1 (PDL1) and Delta-Like Ligand 3 (DLL3), show promise for targeted antibody-based immunotherapy. To ensure optimal patient selection, it remains crucial to comprehend the relationship between PDL1 and DLL3 expression and clinicopathological characteristics in SCLC. In this study, we investigated the expression patterns of PDL1 and DLL3 biomarkers in endobronchial samples from 44 SCLC patients, examining their association with clinical characteristics and survival. High PDL1 expression (>1%) was observed in 14% of patients, while the majority the SCLC patients (73%) exhibited high DLL3 expression (>75%). Notably, we found a positive correlation between high PDL1 expression (>1%) and overall survival. However, we did not observe any significant differences in the biomarkers expression concerning age, sex, disease status, smoking status, or distant metastases. Further subgroup analysis revealed that a high co-expression of both PDL1 (>1%) and DLL3 (100%) antigens was associated with improved overall survival. This suggests that SCLC expressing PDL1 and DLL3 antigens may exhibit increased sensitivity to therapy, indicating their potential as therapeutic targets. Thus, our findings provide novel insights into the simultaneous evaluation of PDL1 and DLL3 biomarkers in SCLC patients. These insights have significant clinical implications for therapeutic strategies, survival prediction, and development of combination immunotherapies.

Rejuvenated iPSC-derived GD2-directed CART Cells Harbor Robust Cytotoxicity Against Small Cell Lung Cancer

Small cell lung cancer (SCLC) is exceptionally aggressive, with limited treatment options. Disialoganglioside (GD2) is highly expressed on SCLC and is considered a good target for chimeric antigen receptor (CAR) T cells (CART). Although GD2-directed CARTs (GD2-CART) exhibit cytotoxicity against various GD2-expressing tumors, they lack significant cytotoxicity against SCLC. To enhance cytotoxicity of GD2-CARTs against SCLC, we introduced GD2-CAR into induced pluripotent stem cells (iPSC)-derived rejuvenated cytotoxic T lymphocytes (GD2-CARrejT). GD2-CARrejTs acted much more strongly against SCLC cells than did GD2-CARTs both in vitro and in vivo. Single-cell RNA sequencing elucidated that levels of expression of TIGIT were significantly lower and levels of expression of genes associated with cytotoxicity were significantly higher in GD2-CARrejTs than those in GD2-CARTs. Dual blockade of TIGIT and programmed death-1 (PD-1) increased the cytotoxicity of GD2-CARTs to some extent, suggesting that low TIGIT and PD-1 expression by GD2-CARrejTs is a major factor required for robust cytotoxicity against SCLC. Not only for robust cytotoxicity but also for availability as "off-the-shelf" T-cell therapy, iPSC-derived GD2-CARrejTs are a promising novel treatment for SCLC.

SIGNIFICANCE

This research introduces iPSC-derived rejuvenated GD2-CARTs (GD2-CARrejT) as a novel approach to combat SCLC. Compared with conventional GD2-CARTs, GD2-CARrejTs with reduced TIGIT and PD-1 expression demonstrate robust cytotoxicity against SCLC and would be a promising therapy for SCLC.

A Systemic Immune Inflammation Index and PD-L1 (SP142) Expression as a Potential Combined Biomarker of the Clinical Benefit of Chemo-Immunotherapy in Extensive-Stage Small-Cell Lung Cancer

Background: No studies have identified combined biomarkers that may be more reasonable for the assessment of current chemo-immunotherapy in patients with extensive stage small-cell lung cancer (ES-SCLC). Methods: This study was conducted to investigate a combined biomarker with prognostic or predictive value in ES-SCLC. We determined the best independent prognostic biomarker among the four complete blood-count-derived inflammatory biomarkers (CBC-IBs). Subsequently, we analyzed the prognostic or predictive value of combining this independent CBC-IB with PD-L1 (SP142) expression. We prospectively assessed the SP142 analyses in tumor samples at diagnosis. Results: All in all, 55 patients with ES-SCLC were classified into four groups according to the systemic immune inflammation index (SII) (low/high) and SP142 (positive/negative). The best survival was observed in the low-SII/ SP142-positive group, whereas the worst survival was observed in the high-SII/SP142-negative group (p = 0.002). The combined SII-SP142 biomarker was better for predicting both survival and disease progression in patients with ES-SCLC. Conclusions: The combined SII-SP142 biomarker can be readily and universally obtained at a low cost in clinical practice, without requiring advanced genomics technology or specialized expertise. Although further studies are needed to confirm that the combined SII-SP142 biomarker is widely applicable, it should help clinicians to identify the best patients for combined chemotherapy with atezolizumab in ES-SCLC.

Unraveling Emerging Anal Cancer Clinical Biomarkers from Current Immuno-Oncogenomics Advances

Anal squamous cell carcinoma (ASCC) is a rare gastrointestinal malignancy associated with high-risk human papillomavirus (HPV) and is currently one of the fastest-growing causes of cancer incidence and mortality in developed countries. Although next-generation sequencing technologies (NGS) have revolutionized cancer and immuno-genomic research in various tumor types, a limited amount of clinical research has been developed to investigate the expression and the functional characterization of genomic data in ASCC. Herein, we comprehensively assess recent advancements in "omics" research, including a systematic analysis of genome-based studies, aiming to identify the most relevant ASCC cancer driver gene expressions and their associated signaling pathways. We also highlight the most significant biomarkers associated with anal cancer progression, gene expression of potential diagnostic biomarkers, expression of therapeutic drug targets, and emerging treatment opportunities. This review stresses the urgent need for developing target-specific therapies in ASCC. By illuminating the molecular characteristics and drug-target expression in ASCC, this study aims to provide insights for the development of precision medicine in anal cancer.

Comparison of Effectiveness of Programmed Death Protein 1 and Programmed Death Ligand 1 Inhibitors in Extensive-Stage Small-Cell Lung Cancer: A Meta-Analysis of Randomized Controlled Trials and Observational Studies

This meta-analysis aimed to compare the efficacy of programmed death protein 1 (PD-1) inhibitors and programmed death ligand 1 (PD-L1) inhibitors in patients with extensive-stage small-cell lung cancer. The present meta-analysis was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Relevant studies were identified through searches of databases including PubMed, Embase, and the Cochrane Library, as well as prominent oncology conferences. The search was conducted from the inception of the databases up to January 31, 2024. A total of 10 studies were included in this meta-analysis. Among these studies, six were randomized trials, while four were observational studies. The pooled meta-analysis showed that PD-1 and PD-L1 inhibitors are more effective in improving overall survival and progression-free survival compared to chemotherapy alone. However, when comparing PD-1 and PD-L1 inhibitors, there was no significant difference between the two groups regarding overall survival and progression-free survival. It is important to note that there is no head-to-head trial comparing these two interventions in patients with extensive-stage small-cell lung cancer. Therefore, future prospective trials are needed to define optimal therapeutic approaches in this patient population.

Prognostic implications of neutrophil-to-lymphocyte ratio in patients with extensive-stage small cell lung cancer receiving chemoimmunotherapy: A multicenter, real-world study

BACKGROUND

Neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are closely related to the prognosis of patients with non-small cell lung cancer, but their effect on extensive-stage small cell lung cancer (ES-SCLC) remains uncertain.

METHODS

This retrospective study was conducted in ES-SCLC patients treated with first-line atezolizumab or durvalumab and platinum-etoposide. Clinical data from three hospitals were analyzed. Significant risk factors for survival were identified using descriptive statistics and Cox regression. Homogeneity was assessed using t-tests or nonparametric tests. Kaplan-Meier analysis revealed an association between high NLR level and median PFS and OS.

RESULTS

A total of 300 ES-SCLC patients were included in the study. Cox regression analysis revealed that an elevated NLR level after the second treatment cycle (defined as NLRT2) was an independent prognostic factor for survival. Stratifying patients based on median NLRT2 showed significant differences in both PFS (HR: 1.863, 95% CI: 1.62-2.12, p < 0.001) and OS (HR: 2.581, 95% CI: 2.19-3.04, p < 0.001) between NLR ≥ 1.75 and NLR < 1.75 groups. mPFS and mOS were 8.2 versus 6.1 months and 13.7 versus 9.5 months, respectively. NLR was also associated with treatment efficacy and occurrence of irAEs. Further stratification based on NLR and irAEs showed that in the NLR < 1.75 group, patients with irAEs had prolonged mPFS and mOS. In the NLR ≥ 1.75 group, only mPFS showed a significant difference between patients with and without irAEs.

CONCLUSION

NLRT2 and irAEs can predict the prognosis of ES-SCLC patients with first-line ES-SCLC receiving PD-L1 inhibitors combined with chemotherapy.

In Search of Lost Biomarker for Immunotherapy in Small Cell Lung Cancer

Chemo-immunotherapy is the current standard of care for extensive-stage small cell lung cancer, but predictive biomarkers are lacking. In a recent article, the authors report the predictive role of programmed death ligand-1 expression and tissue tumor mutational burden on durvalumab ± tremelimumab + platinum-etoposide efficacy. See related article by Paz-Ares et al., p. 824.

Phase 1 study of pembrolizumab plus chemotherapy in Japanese patients with extensive-stage small-cell lung cancer

BACKGROUND

Part E of the KEYNOTE-011 (NCT01840579) study assessed the safety and antitumor activity of pembrolizumab plus platinum-etoposide chemotherapy in Japanese patients with previously untreated extensive-stage small-cell lung cancer (ES-SCLC).

METHODS

Patients received 4 cycles of pembrolizumab (200 mg) every 3 weeks in combination with cisplatin (75 mg/m2) and etoposide (100 mg/m2; days 1, 2, 3) in cohort 1; with carboplatin (AUC 5 mg/mL/min) and etoposide (100 mg/m2; days 1, 2, 3) in cohort 2; or with cisplatin/etoposide and pegfilgrastim (3.6 mg; cycle 1, day 4) in cohort 3. Combination therapy was followed by pembrolizumab monotherapy (31 cycles). The primary endpoint was safety and tolerability (including dose-limiting toxicities; DLTs).

RESULTS

Fifteen patients were included in the study (cohort 1, n = 6; cohort 2, n = 6; cohort 3, n = 3). Median time from treatment allocation to data cutoff was 22.1 months (range, 4.1‒32.4 months). DLTs occurred in 3 patients in cohort 1 (one patient with grade 4 laryngeal stenosis and grade 3 febrile neutropenia; two patients with grade 3 febrile neutropenia); no patients in cohorts 2 or 3 experienced DLTs. Grade ≥ 3 treatment-related adverse events included leukopenia (67%) and neutropenia (87%). Among all patients, ORR was 67% (95% CI, 38%‒88%) and median DOR was 4.5 months (range, 2.8‒28.8 months). Median PFS was 4.2 months (95% CI, 3.0‒7.8 months) and median OS was 22.1 months (95% CI, 7.4‒25.9 months).

CONCLUSION

Pembrolizumab in combination with platinum-etoposide therapy had manageable toxicity with no new safety signals and was associated with antitumor activity in Japanese patients with ES-SCLC.

TRIAL REGISTRATION

ClinicalTrials.gov , NCT01840579.

Tissue and circulating biomarkers of benefit to immunotherapy in extensive-stage small cell lung cancer patients

Extensive stage-Small-Cell Lung Cancer (ES-SCLC) is an aggressive cancer with dismal prognosis. The addition of immune-checkpoint inhibitors (ICIs) to platinum-based chemotherapy have been consistently demonstrated to improve outcomes and survival, becoming the new standard in first - line treatment of ES-SCLC patients. However, despite positive results reported in the pivotal trials, longer benefit appears evident only for a selected group of patients. Several predictive biomarkers have been studied so far but the prospective identification of patients more likely to experience better outcome seems to be challenging in SCLC. Indeed, classical immune predictive biomarkers as PD-L1 and tumor mutational burden (TMB) seem not to correlate with outcomes. Recently, a new molecular classification of SCLC based on differential expression of genes associated with specific clinical behaviors and therapeutic vulnerability have been presented suggesting a new field to be investigated. Despite the achievements, these studies focused mainly on inter-tumoral heterogeneity, limiting the exploration of intra-tumoral heterogeneity and cell to cell interactions. New analysis methods are ongoing in order to explore subtypes plasticity. Analysis on single biopsies cannot catch the whole genomic profile and dynamic change of disease over time and during treatment. Moreover, the availability of tissue for translational research is limited due to the low proportion of patients undergoing surgery. In this context, liquid biopsy is a promising tool to detect reliable predictive biomarkers. Here, we reviewed the current available data on predictive role of tissue and liquid biomarkers in ES-SCLC patients receiving ICIs. We assessed latest results in terms of predictive and prognostic value of gene expression profiling in SCLC. Finally, we explored the role of liquid biopsy as a tool to monitor SCLC patients over time.

Molecular classification of small cell lung cancer subtypes: Characteristics, prognostic factors, and clinical translation

ABSTRACT

Small cell lung cancer (SCLC) is a highly malignant tumor with a very poor prognosis; therefore, more effective treatments are urgently needed for patients afflicted with the disease. In recent years, emerging molecular classifications based on key transcription factors of SCLC have provided more information on the tumor pathophysiology, metastasis, immune microenvironment, and acquired therapeutic resistance and reflected the intertumoral heterogeneity of the various SCLC phenotypes. Additionally, advances in genomics and single-cell sequencing analysis have further revealed the high intratumoral heterogeneity and plasticity of the disease. Herein, we review and summarize these recent lines of evidence and discuss the possible pathogenesis of SCLC.

Efficacy and safety of anti-PD-1 inhibitor versus anti-PD-L1 inhibitor in first-line treatment of extensive-stage small cell lung cancer: a multicenter retrospective study

BACKGROUND

Immunotherapy targeting PD-1/PD-L1 has revolutionized the treatment of extensive-stage small cell lung cancer (ES-SCLC). However, clinical trials suggest differential efficacy of anti-PD-1 agents and anti-PD-L1 agents in first-line treatment of ES-SCLC. This retrospective multicenter study aimed to compare the efficacy and safety of anti-PD-1 agents versus anti-PD-L1 agents in first-line treatment of ES-SCLC in real-world practice.

METHODS

Patients with pathologically or cytologically confirmed ES-SCLC treated with platinum plus etoposide combined with anti-PD-1 or PD-L1 agents as first-line treatment in different centers of PLA General Hospital between January 2017 and October 2021 were included for this study. Survival outcomes and safety were compared between patients receiving anti-PD-1 and PD-L1 agents.

RESULTS

Of the total 154 included patients, 68 received anti-PD-1 agents plus chemotherapy (PD-1 group), and 86 received anti-PD-L1 agents plus chemotherapy (PD-L1 group). Progression-free survival (PFS) and overall survival (OS) in the entire cohort were 7.6 months (95% confidence interval [CI]: 6.5-8.2 months) and 17.4 months (95% CI: 15.3-19.3 months), respectively. Median PFS and OS were comparable between the PD-1 group and PD-L1 group (PFS: 7.6 months vs. 8.3 months, HR = 1.13, 95% CI: 0.79-1.62, p = 0.415; OS: 26.9 months vs. 25.6 months, HR = 0.96, 95% CI: 0.63-1.47, p = 0.859. The objective response rate and disease control rate were comparable between the two groups: 79.4% vs. 79.1% and 92.6% vs. 94.2%, respectively. The 6-month, 12-month, and 18-month PFS and OS rates were slightly higher in the PD-L1 group than in the PD-1 group, while the 24-month PFS rate was slightly higher in the PD-1 group than in the PD-L1 group. Stratified analysis showed that locoregional thoracic radiotherapy and normal lactate dehydrogenase level were independent predictors of better OS in ES-SCLC patients treated with first-line chemotherapy plus ICI. Adverse events were not significantly different between the two groups.

CONCLUSIONS

Anti-PD-1 agents and anti-PD-L1 agents combined with chemotherapy as first-line treatment for ES-SCLC are comparably effective and well tolerated.

Second-Line Treatment Options for Small-Cell Lung Cancer: A Light at the End of the Tunnel

Small-cell lung cancer (SCLC) is a subtype of lung tumor characterized by rapid growth and early metastatic dissemination. It represents approximately 15% of all diagnosed lung cancers, with an annual incidence of over 200,000 cases worldwide. At the time of initial diagnosis, approximately 75-80% of patients already have extrathoracic spread. Almost all patients with SCLC also relapse after achieving a complete response with first-line treatment. Outcomes achievable in second-line treatment are related to the length of time between completion of first-line therapy and disease progression. While first-line chemo-immunotherapy remains the standard of care for initial management, the role of second-line treatment strategies in SCLC has been a topic of significant research and discussion. Second-line treatment options are limited and the results are still disappointing. Several molecules are currently being studied in lines following the first, using immunological targets and cell cycle checkpoints. Among these, particular interest has been placed on anti-PD-1 (programmed cell death-1 protein) and anti-PD-L1 (programmed cell death-ligand 1) monoclonal antibodies, and DLL3 (Delta-like ligand 3), which are being evaluated alone or in combination. Tarlatamab is a novel promising therapeutic antibody currently under investigation for its potential use in previously treated SCLC patients. This mini-review will explore the current state of second-line treatment options for SCLC, their clinical efficacy, and future directions.

Benefits and risks of PD-1/PD-L1 inhibitors for recurrent small cell lung cancer: A systematic review and meta-analysis

The development of immune checkpoint inhibitors(ICIs) has revolutionized the progress of solid tumors. Ongoing clinical trials are exploring the use of checkpoint inhibitors in recurrent small-cell lung cancer and achieving specific results. Although studies have been conducted to systematically review this issue, we conducted this single-arm meta-analysis in light of the emergence of several new clinical studies. In total, 854 individuals from 11 clinical investigations were enrolled in this single-arm meta-analysis. Median progression-free survival, median overall survival, and objective response rate were 1.65 months, 6.83 months, and 20.5%, respectively, according to pooled analyses. The best treatment regimen in the subgroup analysis was a dual checkpoint inhibitor combined with other treatments, and the drug that worked well for treatment was pembrolizumab. The benefit of programmed death 1/programmed cell death-ligand 1(PD-1/PD-L1) inhibitors alone is limited, and their combination with other therapies is a promising treatment option. Among PD-1/PD-L1 inhibitors, pembrolizumab is the recommended drug.

Comparison of Efficacy and Safety of Second-Line Treatment Options for Advanced Small-Cell Lung Cancer: A Retrospective Analysis

OBJECTIVE

As monotherapy such as topotecan has reached a plateau of effectiveness, new second-line treatments based on experience have been used in clinical application. This study compared the efficacy and safety of different second-line treatments for advanced small-cell lung cancer (SCLC).

METHODS

A total of 380 patients with advanced SCLC were screened selectively in the retrospective study. Adverse events and patient responses were assessed using Common Terminology Criteria for Adverse Events v5.0 and Response Evaluation Criteria for Solid Tumors v1.1. The progression-free survival (PFS) was estimated using the Kaplan-Meier method or Cox survival regression model and compared using the log-rank test.

RESULTS

In the platinum-resistant group, disease control rate (DCR) and median PFS (mPFS) were prolonged in the combination group versus single-agent group (DCR: 49.24% vs 24.39%, P = .004; mPFS: 3.73 vs 1.90 months, P < .001). Grade 3/4 toxicity was similar between the 2 groups (P = .683). The mPFS did not differ among single-agent groups (P = .380). No significant difference was observed in mPFS of different combination therapy groups (P = .170). In terms of platinum-based chemotherapy, the DCR and mPFS were prolonged in irinotecan-platinum group versus taxol-platinum group (DCR: 56.14% vs 9.09%, P = .004; mPFS: 3.87 vs 1.93 months, P = .012). Grade 3/4 toxicity was similar between the 2 groups (P = .614). The mPFS was prolonged in the chemotherapy plus immunotherapy group versus single-agent chemotherapy group (P = .003). In the platinum-sensitive group, the mPFS did not differ between the combination group and single-agent group (P = .200). The mPFS did not differ among different single-agent groups (P = .260) or combination groups (P = .150). There was no difference in mPFS among different platinum-based chemotherapy groups (P = .830).

CONCLUSIONS

For patients with platinum-resistant SCLC, combination therapy has shown better efficacy and acceptable toxicity profile than monotherapy. Among combination therapies, irinotecan-platinum has shown better efficacy than taxol-platinum. For patients with platinum-sensitive SCLC, the efficacy of different single-agent or combination therapies was similar.

Nanomedicine Combats Drug Resistance in Lung Cancer

Lung cancer is the second most prevalent cancer and the leading cause of cancer-related death worldwide. Surgery, chemotherapy, molecular targeted therapy, immunotherapy, and radiotherapy are currently available as treatment methods. However, drug resistance is a significant factor in the failure of lung cancer treatments. Novel therapeutics have been exploited to address complicated resistance mechanisms of lung cancer and the advancement of nanomedicine is extremely promising in terms of overcoming drug resistance. Nanomedicine equipped with multifunctional and tunable physiochemical properties in alignment with tumor genetic profiles can achieve precise, safe, and effective treatment while minimizing or eradicating drug resistance in cancer. Here, this work reviews the discovered resistance mechanisms for lung cancer chemotherapy, molecular targeted therapy, immunotherapy, and radiotherapy, and outlines novel strategies for the development of nanomedicine against drug resistance. This work focuses on engineering design, customized delivery, current challenges, and clinical translation of nanomedicine in the application of resistant lung cancer.

Treating patients with platinum-sensitive extensive-stage small-cell lung cancer in a real-world setting

Extensive-stage small-cell lung cancer (ES-SCLC) is an aggressive disease with poor 5-year survival. The first-line standard-of-care for ES-SCLC is platinum plus etoposide, along with 1 of the immune checkpoint inhibitors atezolizumab or durvalumab. Although SCLC first-line therapy often leads to rapid responses, treatment becomes more challenging at progression, particularly for those with a chemotherapy-free interval (CTFI) of ≤6 months. The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for SCLC no longer specify treatment recommendations in this setting, but options approved by the US Food and Drug Administration include topotecan and lurbinectedin. Participation in a clinical trial is recommended as an option regardless of CTFI. Other NCCN-recommended regimens are paclitaxel, irinotecan, temozolomide, and cyclophosphamide/doxorubicin/vincristine, among others. Nivolumab and pembrolizumab are options in those not previously treated with a checkpoint inhibitor. For patients with platinum-sensitive SCLC (CTFI >6 months), preferred treatment per the NCCN Guidelines® for SCLC is retreatment with platinum and etoposide, although the use of immune checkpoint inhibitors is discouraged if there is progression on a drug in this class. Further research on immunotherapies and combination regimens is ongoing, and continuing work on the subcharacterization of SCLC may lead to better precision of therapies that promote more durable responses in individual patients with ES-SCLC.

Systemic Therapy for Small-Cell Lung Cancer: ASCO-Ontario Health (Cancer Care Ontario) Guideline

PURPOSE

To provide evidence-based recommendations to practicing clinicians on the management of patients with small-cell lung cancer.

METHODS

An Expert Panel of medical oncology, thoracic surgery, radiation oncology, pulmonary, community oncology, research methodology, and advocacy experts were convened to conduct a literature search, which included systematic reviews, meta-analyses, and randomized controlled trials published from 1990 through 2022. Outcomes of interest included response rates, overall survival, disease-free survival or recurrence-free survival, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

The literature search identified 95 relevant studies to inform the evidence base for this guideline.

RECOMMENDATIONS

Evidence-based recommendations were developed to address systemic therapy options, timing of therapy, treatment in patients who are older or with poor performance status, role of biomarkers, and use of myeloid-supporting agents in patients with small-cell lung cancer.Additional information is available at www.asco.org/thoracic-cancer-guidelines.

The Era of Immunotherapy in Small-Cell Lung Cancer: More Shadows Than Light?

Small-cell lung cancer is an extremely chemo-sensitive disease; the addition of immunotherapy to chemotherapy has demonstrated a slight clinical benefit in pivotal trials, even with a statistically significant difference in terms of survival outcomes when compared to chemotherapy alone. In this scenario, the role of radiotherapy as a consolidation treatment in thoracic disease or as a prophylactic therapy in the brain should be clarified. In addition, due to the frailty and the poor prognostic characteristics of these patients, the need for predictive biomarkers that could support the use of immunotherapy is crucial. PD-L1 and TMB are not actually considered definitive biomarkers due to the heterogeneity of results in the literature. A new molecular classification of small-cell lung cancer based on the expression of key transcription factors seems to clarify the disease behavior, but the knowledge of this molecular subtype is still insufficient and the application in clinical practice far from reality; this classification could lead to a better understanding of SCLC disease and could provide the right direction for more personalized treatment. The aim of this review is to investigate the current knowledge in this field, evaluating whether there are predictive biomarkers and clinical patient characteristics that could help us to identify those patients who are more likely to respond to immunotherapy.

Comparison of efficacy and safety between PD-1 inhibitors and PD-L1 inhibitors plus platinum-etoposide as first-line treatment for extensive-stage small-cell lung cancer: a multicenter, real-world analysis

BACKGROUND

Immunotherapy in combination with platinum-etoposide (EP) chemotherapy has been approved as a first-line treatment for extensive-stage small cell lung cancer (ES-SCLC). However, real-world (RW) data regarding the use of immune checkpoint inhibitors (ICIs) in ES-SCLC are lacking. We aimed to assess the differences between programmed death protein 1 (PD-1) inhibitors and programmed death ligand 1 (PD-L1) inhibitors, both in conjunction with EP chemotherapy, as first-line treatment for ES SCLC.

METHODS

We conducted a real-world, multicenter, retrospective cohort, controlled study to compare the prognosis, efficacy, and safety of PD-1 and PD-L1 inhibitors in ES-SCLC patients when used along with chemotherapy. Each patient received up to six cycles of etoposide, carboplatin, or cisplatin combined with ICI drugs, including PD-1 and PD-L1 inhibitors. The primary endpoints were investigator-assessed progression-free survival (PFS) and overall survival (OS). The secondary endpoints were the investigator-assessed objective response rate (ORR) and disease control rate (DCR) according to the Response Evaluation Criteria in Solid Tumors (RECIST, version 1.1).

RESULTS

Between January 2017 and December 2021, 194 patients with ES-SCLC from three clinical centers in a PLA general hospital were included in our study, including 93 patients in the PD-1 group and 101 patients in the PD-L1 group. At the time of data cutoff, progression-free survival in the PD-1 group (median PFS, 6.8 months; 95% CI, 5.3-8.1) was similar to that in the PD-L1 group (median PFS, 6.4 months; 95% CI, 5.5-7.5); the stratified hazard ratio for PFS was 1.12 (95% CI, 0.83-1.53; P = 0.452). The median OS was similar in the PD-1 and PD-L1 groups (15.8 m vs. 17.7 m, P = 0.566); the hazard ratio was 0.90 (95% CI, 0.62-1.30, P = 0.566). The two groups had comparable investigator-assessed confirmed objective response rates (ORR) (76.3% vs. 76.2%). Adverse effect (AE)-related discontinuation occurred in 4 (4.3%) patients in the PD-1 group and 2 (2.0%) patients in the PD-L1 group. Deaths due to AEs of any cause occurred in 2 (2.2%) patients in the PD-1 inhibitor group and 1 (1.0%) patient in the PD-L1 inhibitor group.

CONCLUSIONS

Our research revealed that there were no significant differences in efficacy or prognosis between PD-1 inhibitor + EP chemotherapy and PD-L1 inhibitor + EP chemotherapy. The two groups seemed to have comparable safety profiles, but the number of discontinuation or death events was too small to draw a firm conclusion.

Tarlatamab for Patients with Previously Treated Small-Cell Lung Cancer

BACKGROUND

Tarlatamab, a bispecific T-cell engager immunotherapy targeting delta-like ligand 3 and CD3, showed promising antitumor activity in a phase 1 trial in patients with previously treated small-cell lung cancer.

METHODS

In this phase 2 trial, we evaluated the antitumor activity and safety of tarlatamab, administered intravenously every 2 weeks at a dose of 10 mg or 100 mg, in patients with previously treated small-cell lung cancer. The primary end point was objective response (complete or partial response), as assessed by blinded independent central review according to the Response Evaluation Criteria in Solid Tumors, version 1.1.

RESULTS

Overall, 220 patients received tarlatamab; patients had previously received a median of two lines of treatment. Among patients evaluated for antitumor activity and survival, the median follow-up was 10.6 months in the 10-mg group and 10.3 months in the 100-mg group. An objective response occurred in 40% (97.5% confidence interval [CI], 29 to 52) of the patients in the 10-mg group and in 32% (97.5% CI, 21 to 44) of those in the 100-mg group. Among patients with an objective response, the duration of response was at least 6 months in 59% (40 of 68 patients). Objective responses at the time of data cutoff were ongoing in 22 of 40 patients (55%) in the 10-mg group and in 16 of 28 patients (57%) in the 100-mg group. The median progression-free survival was 4.9 months (95% CI, 2.9 to 6.7) in the 10-mg group and 3.9 months (95% CI, 2.6 to 4.4) in the 100-mg group; the estimates of overall survival at 9 months were 68% and 66% of patients, respectively. The most common adverse events were cytokine-release syndrome (in 51% of the patients in the 10-mg group and in 61% of those in the 100-mg group), decreased appetite (in 29% and 44%, respectively), and pyrexia (in 35% and 33%). Cytokine-release syndrome occurred primarily during treatment cycle 1, and events in most of the patients were grade 1 or 2 in severity. Grade 3 cytokine-release syndrome occurred less frequently in the 10-mg group (in 1% of the patients) than in the 100-mg group (in 6%). A low percentage of patients (3%) discontinued tarlatamab because of treatment-related adverse events.

CONCLUSIONS

Tarlatamab, administered as a 10-mg dose every 2 weeks, showed antitumor activity with durable objective responses and promising survival outcomes in patients with previously treated small-cell lung cancer. No new safety signals were identified. (Funded by Amgen; DeLLphi-301 ClinicalTrials.gov number, NCT05060016.).

Advancing immunotherapy in small cell lung cancer

Small cell lung cancer (SCLC) is a rapidly progressive neuroendocrine carcinoma that, until recently, had a very small armamentarium of effective treatments. Advances in DNA sequencing and whole transcriptomics have delineated key subtypes; therefore, SCLC is no longer viewed as a homogeneous cancer. Chemoimmunotherapy with PD1 blockade is now the standard of care for advanced disease, and ongoing research efforts are moving this strategy into the limited stage setting. Combination strategies of immunotherapy with radiation are also under active clinical trial in both limited and extensive stage disease. PLAIN LANGUAGE SUMMARY: Small cell lung cancer (SCLC) is a rapidly progressive neuroendocrine carcinoma that, until recently, had a very small armamentarium of effective treatments. Chemoimmunotherapy with immune check point inhibitors is now the standard of care for advanced disease. This comprehensive review provides an overview of current treatment strategies for SCLC, unmet needs in this patient population, and emerging treatment strategies incorporating immunotherapy that will hopefully further improve outcomes for patients.

PPIs therapy has a negative impact on the clinical outcomes of advanced SCLC patients treated with PD-L1 inhibitors

BACKGROUND

Programmed death-ligand 1 (PD-L1) inhibitors has emerged as a first-line therapeutic strategy for advanced small cell lung cancer (SCLC), which can stimulate T-cell activation, thereby preventing tumor avoidance of immunologic surveillance, whereas, proton pump inhibitors (PPIs) can play an important role in regulating immune function. This study assessed whether the concomitantly use of PPIs affected outcomes of immunotherapy in advanced SCLC.

METHODS

Data from advanced SCLC patients who firstly treated with PD-L1 inhibitors between July 2018 and February 2021 was retrospectively analyzed. The impact of concomitant medications (especially PPIs) on objective response rate, progression-free survival (PFS) and overall survival (OS) were evaluated.

RESULTS

Of 208 patients, 101 received immunotherapy concomitant PPIs. The median PFS of patients receiving PPIs (6.6 months) were significantly shorter than those without PPIs (10.6 months), and so was OS. There was associated with a 74.9% increased risk of progression and 58.3% increased risk of death. Both first-line and post-first-line immunotherapy, patients treated PPIs had poorer PFS.

CONCLUSION

PPIs therapy has a negative impact on the clinical outcomes of advanced SCLC patients treated with PD-L1 inhibitors.

Small cell lung cancer with SYN2::PPARG fusion

INTRODUCTION

Small cell lung cancer (SCLC) accounts for 15% of lung cancers worldwide. It is an aggressive tumor that is typically diagnosed at an advanced stage. Treatment involves chemo-immunotherapy and/or radiotherapy. Identifying druggable targets activated by specific genetic alterations represents a significant challenge in improving patient outcomes.

METHODS

We conducted a retrospective examination of molecular findings in lung cancer patients' records from 2021 to 2022. We discovered a unique case of SCLC harboring the SYN2-PPARG fusion. Histopathological analysis confirmed the diagnosis of SCLC.

CASE REPORT

A 60-year-old woman, a heavy smoker, came to our attention due to a persistent cough with slight hemoptysis. Imaging, including axial contrast-enhanced computed tomography, revealed an advanced disease with extra-thoracic spread. Tumor histology showed a sheet-like proliferation of small-sized cells with a neuroendocrine phenotype and a high proliferation tumor cell fraction. Molecular genetic analysis using NGS approach revealed a fusion involving the SYN2 and PPARG genes.

CONCLUSION

The SYN2-PPARG fusion has recently been documented in sinonasal adenocarcinoma and has been reported in only a single SCLC case previously. Highlighting the molecular heterogeneity within this aggressive form of lung cancer could potentially aid in the selection of specific therapies.

Treatment and survival of patients with small cell lung cancer and brain metastasis

PURPOSE

To elucidate treatment patterns and their outcomes in patients with small cell lung cancer (SCLC) and brain metastasis (BM).

METHODS

In this retrospective study, patients with SCLC and BM were stratified by treatment modality into three groups: those treated with systemic therapy only, those treated with stereotactic radiosurgery (SRS) and systemic therapy, and those treated with whole-brain radiotherapy (WBRT) and systemic therapy. The primary outcomes were overall survival (OS) and time to central nervous system progression (TTCP).

RESULTS

The analysis included 149 patients. After BM diagnosis, 48 patients (32.2%) received systemic therapy alone, 33 received SRS with systemic therapy, and 68 received WBRT with systemic therapy. The median OS and TTCP were 7.2 months and 8.7 months, respectively. Patients receiving WBRT with systemic therapy exhibited better intracranial control, but not better OS, than did the other patients. Key prognostic factors affecting OS were age, BM lesion count, chemotherapy, and immunotherapy. Notably, the Eastern Cooperative Oncology Group performance status and BM lesion count significantly influenced intracranial control in patients treated with SRS and systemic therapy.

CONCLUSION

Although WBRT combined with systemic therapy offer better intracranial control in patients with SCLC and BM, this approach is not superior to the other approaches in terms of OS benefits. Emerging systemic therapies, such as immunotherapy, may be used as alternative or adjunctive treatments for specific patient populations. Further studies are warranted to refine treatment selection.

Immune-Related Adverse Events in Patients with Lung Cancer

PURPOSE OF REVIEW

Immune checkpoint inhibitors (ICI) have been widely adopted for the treatment of lung cancer since receiving first U.S Food and Drug Administration (FDA) approval in 2015. However, along with their use, the occurrence of immune-related adverse events (irAEs) has presented a challenge for both patients and oncology providers. In this manuscript, we reviewed the clinical trials that led to the approval of ICI by the FDA for the treatment of lung cancer between 2015 and 2023 to establish the frequency of irAEs in this patient population. Among the adverse events associated with ICI, we focused on the most common and relevant ones, including hypothyroidism, pneumonitis, diarrhea/colitis, skin rash, and hepatitis.

RECENT FINDINGS

We thoroughly examined the available literature, including society guidelines concerning these complications, to discuss various aspects such as their pathophysiology, epidemiology, diagnostic process, grading system, and clinical management. Additionally, we explored the association between irAEs and disease response. The management of irAEs is a crucial aspect of oncologic care, particularly due to their potential to cause severe and life-threatening clinical manifestations. We present each pertinent aspect in a concise and organized manner to provide guidance and assistance to oncology providers managing these patients in both outpatient and inpatient settings.

Clinical insights into small cell lung cancer: Tumor heterogeneity, diagnosis, therapy, and future directions

Small cell lung cancer (SCLC) is characterized by rapid growth and high metastatic capacity. It has strong epidemiologic and biologic links to tobacco carcinogens. Although the majority of SCLCs exhibit neuroendocrine features, an important subset of tumors lacks these properties. Genomic profiling of SCLC reveals genetic instability, almost universal inactivation of the tumor suppressor genes TP53 and RB1, and a high mutation burden. Because of early metastasis, only a small fraction of patients are amenable to curative-intent lung resection, and these individuals require adjuvant platinum-etoposide chemotherapy. Therefore, the vast majority of patients are currently being treated with chemoradiation with or without immunotherapy. In patients with disease confined to the chest, standard therapy includes thoracic radiotherapy and concurrent platinum-etoposide chemotherapy. Patients with metastatic (extensive-stage) disease are treated with a combination of platinum-etoposide chemotherapy plus immunotherapy with an anti-programmed death-ligand 1 monoclonal antibody. Although SCLC is initially very responsive to platinum-based chemotherapy, these responses are transient because of the development of drug resistance. In recent years, the authors have witnessed an accelerating pace of biologic insights into the disease, leading to the redefinition of the SCLC classification scheme. This emerging knowledge of SCLC molecular subtypes has the potential to define unique therapeutic vulnerabilities. Synthesizing these new discoveries with the current knowledge of SCLC biology and clinical management may lead to unprecedented advances in SCLC patient care. Here, the authors present an overview of multimodal clinical approaches in SCLC, with a special focus on illuminating how recent advancements in SCLC research could accelerate clinical development.

MTX-13, a Novel PTK7-Directed Antibody-Drug Conjugate with Widened Therapeutic Index Shows Sustained Tumor Regressions for a Broader Spectrum of PTK7-Positive Tumors

Protein tyrosine kinase 7 (PTK7) is a Wnt signaling pathway protein implicated in cancer development and metastasis. When using a potent microtubule inhibitor (Aur0101), PTK7-targeting antibody-drug conjugate (ADC), h6M24-vc0101 (PF-06647020/cofetuzumab pelidotin) is efficacious only in limited tumor types with low response rates in a phase I trial. To improve patient response and to expand responding tumor types, we designed MTX-13, a PTK7-targeting ADC consisting of a novel antibody (Ab13) conjugated to eight molecules of topoisomerase I inhibitor exatecan through T1000, a novel self-immolative moiety. MTX-13 exhibited PTK7-specific cell binding, efficient internalization, and exatecan release to cause cytotoxic activity through DNA damage and apoptosis induction, and a strong bystander killing. MTX-13 displayed potent antitumor activities on cell line-derived xenograft and patient-derived xenograft models from a wide range of solid tumors, significantly outperforming h6M24-vc0101. PTK7 was shown to be an actionable target in small cell lung cancer for which MTX-13 showed complete and durable responses. With a consistent overexpression of PTK7 in squamous cell carcinomas derived from diverse anatomic sites, strong potency of MTX-13 in this group of heterogenous tumors suggested a common treatment strategy. Finally, MTX-13 inhibited tumor growth and metastasis in an orthotopic colon cancer xenograft model. MTX-13 displayed a favorable pharmacokinetic and safety profile in monkeys with the highest non-severely toxic dose (HNSTD) of ≥30 mg/kg, significantly higher than 3-5 mg/kg of HNSTD for h6M24-vc0101. The higher therapeutic index of MTX-13 bodes well for its clinical translation with the potential to expand the responding patient population beyond that of current PTK7-targeting ADCs.

Comparison of PD-L1 expression and MMR status between primary and matched metastatic lesions in patients with cervical cancer

PURPOSE

Programmed death-ligand 1 (PD-L1) and DNA mismatch repair (MMR) are considered predictive biomarkers for immunotherapy in cervical cancer. However, their expression in primary tumors and metastases does not always match affecting the course of treatment. We investigated the consistency of their expression in primary and matched recurrent/metastatic lesions from patients with cervical cancer.

METHODS

Primary and matched recurrent/metastatic specimens from patients with recurrent cervical cancer (n = 194) were stained for PD-L1 and MMR (MLHI, MSH6, MSH2, and PMS2) using immunohistochemistry. The degree of consistency of PD-L1 and MMR expression in these lesions was analyzed.

RESULTS

The inconsistency rate of PD-L1 expression in primary and recurrent/metastatic lesions was 33.0%, and it varied between the recurrence sites. Positive PD-L1 rate in primary lesions was lower (15.4%) than that in recurrent/metastatic lesions (30.4%). The discordance rate of MMR expression between primary and recurrent/metastatic lesions was 4.1%.

CONCLUSION

We conclude that to use PD-L1 as a predictive biomarker for immunotherapy, analysis of both metastatic and primary lesions may be required. High consistency rate of MMR expression between primary and metastatic lesions suggests that testing primary lesions alone can be sufficient for guiding the course of therapy, thereby solving the difficulty of obtaining recurrent/metastatic specimens in clinic.

Investigation of the efficacy and feasibility of combined therapy of PD-L1-enhanced exogenous peripatetic adoptive natural killer (NK) cells in combination with antiangiogenic targeted therapy in the treatment of extensive-stage small cell lung cancer

A 67-year-old male patient presented with extensive-stage small cell lung cancer with the primary lesion located in the right upper lung, accompanied by multiple metastases to the pleura and abdominal cavity with enlarged mediastinal lymph nodes. A combination therapy approach was used to target the patient's multiple systemic metastases after localized radiotherapy. The approach involved adoptive transfer of programmed death ligand 1 (PD-L1) enhanced exogenous natural killer (NK) cells, along with antiangiogenic treatment. Allogeneic cord blood NK cells were infused back into the patient over two consecutive days. On the first day, the treatment was followed by a dose of 1200 mg of atezolizumab. Subsequently, the patient received a daily dose of 10 mg of anlotinib administered orally for 14 days. This was followed by a 7-day break, and each cycle lasted 21 days. After delivering localized radiation to the primary lesion in the right lung and metastatic mediastinal lymph nodes, complete remission was achieved in the local lesion, effectively avoiding the risk of superior vena cava syndrome. Following six cycles of combined therapy, most of the metastatic lesions had disappeared, and the remaining metastatic lesions had significantly reduced in size. The recent therapeutic effect resulted in partial remission. The combination therapy of immune checkpoint inhibitor PD-L1-enhanced exogenous adoptive transfer NK cells, along with antiangiogenic targeted treatment, demonstrated a satisfactory short-term effect, with disappearance of most of the metastases and noticeable shrinkage in the remaining metastatic lesions.

Lineage Plasticity in SCLC Generates Non-Neuroendocrine Cells Primed for Vasculogenic Mimicry

INTRODUCTION

Vasculogenic mimicry (VM), the process of tumor cell transdifferentiation to endow endothelial-like characteristics supporting de novo vessel formation, is associated with poor prognosis in several tumor types, including SCLC. In genetically engineered mouse models (GEMMs) of SCLC, NOTCH, and MYC co-operate to drive a neuroendocrine (NE) to non-NE phenotypic switch, and co-operation between NE and non-NE cells is required for metastasis. Here, we define the phenotype of VM-competent cells and molecular mechanisms underpinning SCLC VM using circulating tumor cell-derived explant (CDX) models and GEMMs.

METHODS

We analyzed perfusion within VM vessels and their association with NE and non-NE phenotypes using multiplex immunohistochemistry in CDX, GEMMs, and patient biopsies. We evaluated their three-dimensional structure and defined collagen-integrin interactions.

RESULTS

We found that VM vessels are present in 23/25 CDX models, 2 GEMMs, and in 20 patient biopsies of SCLC. Perfused VM vessels support tumor growth and only NOTCH-active non-NE cells are VM-competent in vivo and ex vivo, expressing pseudohypoxia, blood vessel development, and extracellular matrix organization signatures. On Matrigel, VM-primed non-NE cells remodel extracellular matrix into hollow tubules in an integrin β1-dependent process.

CONCLUSIONS

We identified VM as an exemplar of functional heterogeneity and plasticity in SCLC and these findings take considerable steps toward understanding the molecular events that enable VM. These results support therapeutic co-targeting of both NE and non-NE cells to curtail SCLC progression and to improve the outcomes of patients with SCLC in the future.

Consensus report of the 2021 National Cancer Institute neuroendocrine tumor clinical trials planning meeting

Important progress has been made over the last decade in the classification, imaging, and treatment of neuroendocrine neoplasm (NENs), with several new agents approved for use. Although the treatment options available for patients with well-differentiated neuroendocrine tumors (NETs) have greatly expanded, the rapidly changing landscape has presented several unanswered questions about how best to optimize, sequence, and individualize therapy. Perhaps the most important development over the last decade has been the approval of 177Lu-DOTATATE for treatment of gastroenteropancreatic-NETs, raising questions around optimal sequencing of peptide receptor radionuclide therapy (PRRT) relative to other therapeutic options, the role of re-treatment with PRRT, and whether PRRT can be further optimized through use of dosimetry among other approaches. The NET Task Force of the National Cancer Institute GI Steering Committee convened a clinical trial planning meeting in 2021 with multidisciplinary experts from academia, the federal government, industry, and patient advocates to develop NET clinical trials in the era of PRRT. Key clinical trial recommendations for development included 1) PRRT re-treatment, 2) PRRT and immunotherapy combinations, 3) PRRT and DNA damage repair inhibitor combinations, 4) treatment for liver-dominant disease, 5) treatment for PRRT-resistant disease, and 6) dosimetry-modified PRRT.

A multicenter, single-arm, open study of neoadjuvant or conversion atezolizumab in combination with chemotherapy in resectable small cell lung cancer (Cohort Study)

BACKGROUND

This study aimed to investigate the prospects of using chemotherapy in combination with atezolizumab in the neoadjuvant or conversion treatment of small cell lung cancer (SCLC).

METHODS

Prior to surgery, untreated patients with limited-stage SCLC received three cycles of neoadjuvant or conversion atezolizumab combined with chemotherapy of etoposide and platinum. The primary endpoint of the trial was pathological complete response (pCR) in the per-protocol (PP) cohort. In addition, safety was assessed based on treatment-related adverse events (AEs) and postoperative complications.

RESULTS

Overall, 13 of 17 patients (including 14 males and 3 females) underwent surgery. In the PP cohort, pCR and major pathological response were observed in 8 (8/13, 61.5%) and 12 (12/13, 92.3%) patients, respectively. According to the intention-to-treat (ITT) analysis, the pCR and major pathological response in the ITT cohort were 47.1% (8/17) and 70.6% (12/17), respectively. In addition, an overall response rate of 100% was recorded in the PP cohort. Moreover, 15 (15/17, 88.2%) patients and 1 (1/17, 5.9%) in the ITT cohort attained partial remission (PR), and complete remission, respectively, with an overall response rate of 94.1%. The median overall survival of the patients of pCR and the median event-free survival of the patients on surgery had not achieved. However, the median overall survival of the patients of non-pCR was 18.2 months and the median event-free survival of the nonsurgical patients was 9.5 months. During the neoadjuvant treatment, the incidence of grade 3 or higher AEs was 58.8% (10/17). Additionally, three patients (17.6%) developed immune-related adverse event (grades 1-2).

CONCLUSION

In patients with SCLC, neoadjuvant or conversion atezolizumab combined with chemotherapy significantly improved pCR with manageable AEs. Therefore, this regimen may be considered a safe and effective treatment for SCLC.

Potent molecular-targeted therapies for gastro-entero-pancreatic neuroendocrine carcinoma

Neuroendocrine neoplasms (NENs), which are characterized by neuroendocrine differentiation, can arise in various organs. NENs have been divided into well-differentiated neuroendocrine tumors (NETs) and poorly differentiated neuroendocrine carcinomas (NECs) based on morphological differentiation, each of which has a distinct etiology, molecular profile, and clinicopathological features. While the majority of NECs originate in the pulmonary organs, extrapulmonary NECs occur most predominantly in the gastro-entero-pancreatic (GEP) system. Although platinum-based chemotherapy is the main therapeutic option for recurrent or metastatic GEP-NEC patients, the clinical benefits are limited and associated with a poor prognosis, indicating the clinically urgent need for effective therapeutic agents. The clinical development of molecular-targeted therapies has been hampered due to the rarity of GEP-NECs and the paucity of knowledge on their biology. In this review, we summarize the biology, current treatments, and molecular profiles of GEP-NECs based on the findings of pivotal comprehensive molecular analyses; we also highlight potent therapeutic targets for future precision medicine based on the most recent results of clinical trials.

SEOM-GECP Clinical guidelines for diagnosis, treatment and follow-up of small-cell lung cancer (SCLC) (2022)

Small-cell lung cancer (SCLC) is a highly aggressive malignancy comprising approximately 15% of lung cancers. Only one-third of patients are diagnosed at limited-stage (LS). Surgical resection can be curative in early stages, followed by platinum-etoposide adjuvant therapy, although only a minority of patients with SCLC qualify for surgery. Concurrent chemo-radiotherapy is the standard of care for LS-SCLC that is not surgically resectable, followed by prophylactic cranial irradiation (PCI) for patients without progression. For extensive-stage (ES)-SCLC, a combination of platinum and etoposide has historically been a mainstay of treatment. Recently, the efficacy of programmed death-ligand 1 inhibitors combined with chemotherapy has become the new front-line standard of care for ES-SCLC. Emerging knowledge regarding SCLC biology, including genomic characterization and molecular subtyping, and new treatment approaches will potentially lead to advances in SCLC patient care.

Extensive-Stage Small-Cell Lung Cancer: Current Landscape and Future Prospects

Small-cell lung cancer (SCLC) is characterized by aggressive disease progression and tendency to metastasize. Although chemotherapy for extensive-stage SCLC (ES-SCLC) has remained unchanged for decades, immune checkpoint inhibitors have become the primary therapy for ES-SCLC. However, the number of patients benefiting from immunotherapy is limited, and the treatment outcomes remain unsatisfactory. In addition, predictive biomarkers for immunotherapy have not yet been identified. Recent reports have shed light on the genomics of SCLC and defined four distinct molecular subtypes based on transcription factor expression. This may increase our understanding of the biology of SCLC and identify novel therapeutic targets and drugs. In this article, we review the current standard management of ES-SCLC and present the most recent reports to further our understanding of molecular classification, predictive biomarkers, and prospective therapies, including immunotherapy, chemotherapy, and targeted therapy.

YTHDF2 negatively correlates with tumor immune infiltration in small cell lung cancer

In recent times, RNA modifications have garnered increased attention due to their involvement in the onset and progression of tumors, with N6-methyladenosine (m6A) modification being the most prevalent form. YTHDF2 is an m6A reading protein that can modulate RNA stability, transcription, and translation. This study aimed to explore the role of YTHDF2 in small cell lung cancer (SCLC) by collecting 20 SCLC patients from our hospital (cohort 1) and 48 Chinese SCLC patients from the GEO database (cohort 2). We evaluated the prognostic value of YTHDF2 using Kaplan-Meier survival analysis, Log-rank test, and Cox regression analysis. Additionally, we employed Gene Set Enrichment Analysis (GSEA) to screen different signaling pathways. We also investigated the correlation between the expression of m6A-related genes and SCLC molecular subtype and tumor immune microenvironment (TIME). Furthermore, we utilized multiplex immunofluorescence (mIF) staining to validate the immune infiltration of SCLC patient tissue sections. Our study revealed that YTHDF2 is an independent prognostic factor, which high expression is associated with low overall survival rate in SCLC. Low expression of YTHDF2 in SCLC tumors may enhance the molecular subtype transition from neuroendocrine (NE) to non-neuroendocrine (non-NE) subtype. Low YTHDF2 expression was closely associated with high immune infiltration, immune checkpoints, and other immune-related molecular features. Additionally, mIF detection showed a correlation between the low expression of YTHDF2 and CD4 + T cells and CD8 + T cells. Taken together, YTHDF2 could serve as a potential prognostic biomarker negatively correlated with tumor immune infiltration in SCLC.

Pembrolizumab alone and pembrolizumab plus chemotherapy in previously treated, extrapulmonary poorly differentiated neuroendocrine carcinomas

BACKGROUND

To date, single-agent immune checkpoint inhibitor (CPI) therapy has proven to be ineffective against biomarker-unselected extrapulmonary poorly differentiated neuroendocrine carcinomas (EP-PDNECs). The efficacy of CPI in combination with chemotherapy remains under investigation.

METHODS

Patients with advanced, progressive EP-PDNECs were enrolled in a two-part study of pembrolizumab-based therapy. In Part A, patients received pembrolizumab alone. In Part B, patients received pembrolizumab plus chemotherapy.

PRIMARY ENDPOINT

objective response rate (ORR). Secondary endpoints: safety, progression-free survival (PFS) and overall survival (OS). Tumours were profiled for programmed death-ligand 1 expression, microsatellite-high/mismatch repair deficient status, mutational burden (TMB), genomic correlates. Tumour growth rate was evaluated.

RESULTS

Part A (N = 14): ORR (pembrolizumab alone) 7% (95% CI, 0.2-33.9%), median PFS 1.8 months (95% CI, 1.7-21.4), median OS 7.8 months (95% CI, 3.1-not reached); 14% of patients (N = 2) had grade 3/4 treatment-related adverse events (TRAEs). Part B (N = 22): ORR (pembrolizumab plus chemotherapy) 5% (95% CI, 0-22.8%), median PFS 2.0 months (95% CI, 1.9-3.4), median OS 4.8 months (95% CI, 4.1-8.2); 45% of patients (N = 10) had grade 3/4 TRAEs. The two patients with objective response had high-TMB tumours.

DISCUSSION

Treatment with pembrolizumab alone and pembrolizumab plus chemotherapy was ineffective in advanced, progressive EP-PDNECs.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov NCT03136055.