Efficacy and Safety of Rovalpituzumab Tesirine in Third-Line and Beyond Patients with DLL3-Expressing, Relapsed/Refractory Small-Cell Lung Cancer: Results From the Phase II TRINITY Study

Genomics of Breast Cancer Brain Metastases: A Meta-Analysis and Therapeutic Implications

Breast cancer brain metastases are a challenging daily practice, and the biological link between gene mutations and metastatic spread to the brain remains to be determined. Here, we performed a meta-analysis on genomic data obtained from primary tumors, extracerebral metastases and brain metastases, to identify gene alterations associated with metastatic processes in the brain. Articles with relevant findings were selected using Medline via PubMed, from January 1999 up to February 2022. A critical review was conducted according to the Preferred Reporting Items for Systematic Review and Meta-analysis statement (PRISMA). Fifty-seven publications were selected for this meta-analysis, including 37,218 patients in all, 11,906 primary tumor samples, 5541 extracerebral metastasis samples, and 1485 brain metastasis samples. We report the overall and sub-group prevalence of gene mutations, including comparisons between primary tumors, extracerebral metastases and brain metastases. In particular, we identified six genes with a higher mutation prevalence in brain metastases than in extracerebral metastases, with a potential role in metastatic processes in the brain: ESR1, ERBB2, EGFR, PTEN, BRCA2 and NOTCH1. We discuss here the therapeutic implications. Our results underline the added value of obtaining biopsies from brain metastases to fully explore their biology, in order to develop personalized treatments.

Targeting the Notch signaling pathway and the Notch ligand, DLL3, in small cell lung cancer

Small cell lung cancer (SCLC) is a highly aggressive and poorly differentiated cancer with high-grade neuroendocrine (NE) features, accounting for approximately 15 % of all lung cancers. For decades, chemotherapy and radiotherapy have predominated the treatment strategy for SCLC, but relapses ensue quickly and result in poor survival of patients. Immunotherapy has brought novel insights, yet the efficacy is still restricted to a limited population with SCLC. Notch signaling is identified to play a key role in the initiation and development of SCLC, and the Notch ligand, Delta-like ligand 3 (DLL3) is found broadly and specifically expressed in SCLC cells. Thus, Notch signaling is under active exploration as a potential therapeutic target in SCLC. Herein, we summarized and updated the functional relevance of Notch signaling in SCLC, discussed Notch signaling-targeted therapy for SCLC and the correspondent preclinical and clinical trials, and investigated the promising synergy effects of Notch signaling targeted therapy and immune checkpoint inhibitors (ICIs) treatment.

Emerging Strategies for the Treatment of Small Cell Lung Cancer: A Review

Importance

Small cell lung cancer (SCLC) is an aggressive disease that is characterized by rapid growth and the early development of metastases. Patients typically respond to initial chemotherapy but quickly experience relapse, resulting in a poor long-term outcome. Therapeutic innovations that substantially improve survival have historically been limited, and reliable, predictive biomarkers are lacking.

Observations

This review examines the biologic characteristics of SCLC, the current treatment landscape, and ongoing efforts to identify novel therapeutic targets. Ongoing research has advanced the understanding of molecular categories and the immunologic microenvironment of SCLC, which in turn has helped improve disease classification and staging. Recently, immunotherapy-based regimens have become available for the management of SCLC, with 2 programmed cell death 1 ligand 1 inhibitors approved in combination with chemotherapy for first-line treatment of extensive-stage disease. For second-line treatment, a novel alkylating agent, lurbinectedin, which inhibits oncogenic transcription, has been approved for use in patients with metastatic SCLC. Furthermore, a wide variety of therapies and innovative combination regimens are being continuously evaluated. Potential therapeutic strategies, including aurora kinase A inhibitors, polyadenosine diphosphate-ribose polymerase inhibitors, ataxia telangiectasia and Rad3-related inhibitors, cyclin-dependent kinase 7 inhibitors, delta-like protein 3 agents, antiganglioside agents, CD47 inhibitors, and lysine-specific histone demethylase 1a inhibitors, are also being examined.

Conclusions and Relevance

Therapeutic optimization of SCLC remains a challenge, but recent trial results and drug approvals are encouraging. Advances in research have revealed critical information regarding biologic characteristics of the disease, which may lead to the identification of vulnerabilities and the development of new therapies. Further research focused on identifying biomarkers and evaluating innovative therapies will be paramount to improving treatment outcomes for patients with SCLC.

Allogeneic CAR T Cells Targeting DLL3 Are Efficacious and Safe in Preclinical Models of Small Cell Lung Cancer

PURPOSE

Small cell lung cancer (SCLC) is an aggressive disease with limited treatment options. Delta-like ligand 3 (DLL3) is highly expressed on SCLC and several other types of neuroendocrine cancers, with limited normal tissue RNA expression in brain, pituitary, and testis, making it a promising CAR T-cell target for SCLC and other solid tumor indications.

EXPERIMENTAL DESIGN

A large panel of anti-DLL3 scFv-based CARs were characterized for both in vitro and in vivo activity. To understand the potential for pituitary and brain toxicity, subcutaneous or intracranial tumors expressing DLL3 were implanted in mice and treated with mouse cross-reactive DLL3 CAR T cells.

RESULTS

A subset of CARs demonstrated high sensitivity for targets with low DLL3 density and long-term killing potential in vitro. Infusion of DLL3 CAR T cells led to robust antitumor efficacy, including complete responses, in subcutaneous and systemic SCLC in vivo models. CAR T-cell infiltration into intermediate and posterior pituitary was detected, but no tissue damage in brain or pituitary was observed, and the hormone-secretion function of the pituitary was not ablated.

CONCLUSIONS

In summary, the preclinical efficacy and safety data presented here support further evaluation of DLL3 CAR T cells as potential clinical candidates for the treatment of SCLC.

Rare Combined Small Cell Lung Carcinoma and Lung Squamous Cell Carcinoma Response to PD-1 Inhibitor as Third-Line Therapy: A Case Report

Background

Combined small cell lung cancer (c-SCLC) is a relatively rare subtype of SCLC, especially when SCLC is initially diagnosed and recurrent lesions are non-small cell lung cancer (NSCLC). Moreover, SCLC combined lung squamous cell carcinoma (LUSC) has few been reported.

Case Presentation

Here, we report a 68-year-old man pathologically diagnosed as stage IV SCLC of right lung. With cisplatin and etoposide, the lesions were significantly reduced. It was not until three years later that a new lesion was found in his left lung, pathologically confirmed as LUSC. The patient was initiated with sintilimab based on high tumor mutational burden (TMB-H). Both lung tumors were stable, and PFS was 9.7 months.

Conclusion

This case provides a meaningful reference for the third-line treatment of SCLC combined LUCS patients. This case also provides valuable information on the response to PD-1 inhibition of patients with c-SCLC based on TMB-H and better understanding of PD-1 therapy applications in the future.

Lung cancer immunotherapy: progress, pitfalls, and promises

Lung cancer is the primary cause of mortality in the United States and around the globe. Therapeutic options for lung cancer treatment include surgery, radiation therapy, chemotherapy, and targeted drug therapy. Medical management is often associated with the development of treatment resistance leading to relapse. Immunotherapy is profoundly altering the approach to cancer treatment owing to its tolerable safety profile, sustained therapeutic response due to immunological memory generation, and effectiveness across a broad patient population. Different tumor-specific vaccination strategies are gaining ground in the treatment of lung cancer. Recent advances in adoptive cell therapy (CAR T, TCR, TIL), the associated clinical trials on lung cancer, and associated hurdles are discussed in this review. Recent trials on lung cancer patients (without a targetable oncogenic driver alteration) reveal significant and sustained responses when treated with programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) checkpoint blockade immunotherapies. Accumulating evidence indicates that a loss of effective anti-tumor immunity is associated with lung tumor evolution. Therapeutic cancer vaccines combined with immune checkpoint inhibitors (ICI) can achieve better therapeutic effects. To this end, the present article encompasses a detailed overview of the recent developments in the immunotherapeutic landscape in targeting small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). Additionally, the review also explores the implication of nanomedicine in lung cancer immunotherapy as well as the combinatorial application of traditional therapy along with immunotherapy regimens. Finally, ongoing clinical trials, significant obstacles, and the future outlook of this treatment strategy are also highlighted to boost further research in the field.

Current and Emerging Treatment Options for Patients With Relapsed Small-cell Lung Carcinoma: A Systematic Literature Review

Second-line treatment options are limited for patients with small-cell lung cancer (SCLC). We conducted a PRISMA-standard systematic literature review to evaluate the treatment landscape for patients with relapsed SCLC (PROSPERO number: CRD42022299759). Systematic searches of MEDLINE, Embase, and Cochrane Library were performed (October 2022) to identify publications (prior 5 years) from prospective studies of therapies for relapsed SCLC. Publications were screened against predetermined eligibility criteria; data were extracted to standardized fields. Publication quality was assessed using GRADE. The data were analyzed descriptively, grouped by drug class. Overall, 77 publications involving 6349 patients were included. Studies of tyrosine kinase inhibitors (TKIs) with established cancer indications accounted for 24 publications; topoisomerase I inhibitors for 15; checkpoint inhibitors (CPIs) for 11, and alkylating agents for 9 publications. The remaining 18 publications featured chemotherapies, small-molecule inhibitors, investigational TKIs and monoclonal antibodies, and a cancer vaccine. According to GRADE assessment, 69% of the publications reported low-/very-low-quality evidence; quality limitations included lack of randomization and small sample sizes. Only 6 publications/6 trials reported phase 3 data; 5 publications/2 trials reported phase 2/3 results. Overall, the clinical potential of alkylating agents and CPIs remained unclear; investigations of combination approaches and biomarker-directed usage are warranted. Phase 2 data from TKI trials were consistently promising; no phase 3 data were available. Phase 2 data for a liposomal formulation of irinotecan were promising. We confirmed an absence of promising investigational drug/regimens in late-stage development; thus, relapsed SCLC remains an area of high unmet need.

Cancer stem cell-immune cell collusion in immunotherapy

Immunotherapy has pioneered a new era of tumor treatment, in which the immune checkpoint blockade (ICB) exerts significant superiority in overcoming tumor immune escape. However, the formation of an immune-suppressive tumor microenvironment (TME) and the lack of effective activation of the immune response have become major obstacles limiting its development. Emerging reports indicate that cancer stem cells (CSCs) potentially play important roles in treatment resistance and progressive relapse, while current research is usually focused on CSCs themselves. In this review, we mainly emphasize the collusions between CSCs and tumor-infiltrating immune cells. We focus on the summary of CSC-immune cell crosstalk signaling pathways in ICB resistance and highlight the application of targeted drugs to improve the ICB response.

Targeting the DLL/Notch Signaling Pathway in Cancer: Challenges and Advances in Clinical Development

The DLL/Notch signaling pathway plays an important role in cancer as a key driver in maintaining cancer stemness and inducing tumor angiogenesis. Many different types of DLL/Notch inhibitors have been developed and explored in clinical trials for cancer treatment, including small-molecule compounds to inhibit gamma-secretase and antibodies targeting Notch ligands or receptors. Despite promising efficacy of these inhibitors in preclinical studies, the overall clinical outcomes have been insufficient to advance to the next stage of clinical development primarily due to safety concerns or modest efficacy. To overcome the narrow therapeutic window of DLL/Notch inhibitors, diverse strategies for improving the balance between the safety and efficacy are currently being explored. Here, we review the clinical perspective and potential of DLL/Notch inhibitors as anticancer agents based on recent results from multiple clinical studies. An antibody specifically targeting Notch ligands or receptors may offer a better approach to reduce concerns about toxicity derived from broad-spectrum DLL/Notch blockers. In addition, combination therapy with an angiogenesis inhibitor targeting VEGF could be a better option for increasing anticancer efficacy. Taken together, the results of clinical trials suggest a bispecific antibody blocking the DLL/Notch and VEGF/VEGFR signaling pathways as a promising approach for effective anticancer treatment.

Challenges in the treatment of small cell lung cancer in the era of immunotherapy and molecular classification

For many years the standard of care for small cell lung cancer (SCLC) has remained unchanged. Despite decades of active research, current treatment options are limited and the prognosis of patients with extended disease (ED) SCLC remains poor. The introduction of immune checkpoint inhibitors (ICIs) represents an exception and the only recent approval for ED-SCLC. However, the magnitude of benefit obtained with immunotherapy in SCLC is much more modest than that observed in other malignancies. Different pro-immunogenic or immunosuppressive features within the tumor microenvironment of SCLC may either modulate the sensitivity to immunotherapy or conversely dampen the efficacy of ICIs. Beside immunotherapy, a deeper understanding of the molecular biology of SCLC has led to the identification of new therapeutic targets for this lethal malignancy. Recent epigenetic and gene expression studies have resulted into a new molecular classification of four distinct subtypes of SCLC, defined by the relative expression of key transcription regulators and each characterized by specific therapeutic vulnerabilities. This review discusses the rationale for immunotherapy in SCLC and summarizes the main ICIs-trials in this tumor. We provide also an overview of new potential therapeutic opportunities and their integration with the new molecular classification of SCLC.

Landscape of the clinical development of China innovative anti-lung cancer drugs

Even today, lung cancer remains one of the most frequently diagnosed cancers and the leading cause of cancer-related deaths worldwide. Throughout the past decades, remarkable advances have been made in the research and development of anti-lung cancer drugs in China. Since the first registered Chinese clinical trial on May 2, 2006, many potent anti-lung cancer drugs have been developed and approved by the China Food and Drug Administration and the National Medical Product Administration of China. Among them, the most advance were observed in the development of targeted agents and immunotherapeutic agents such as epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) icotinib, aumolertinib, and furmonertinib, anaplastic lymphoma kinase (ALK)-TKI ensartinib, programmed cell death-1 (PD-1) monoclonal antibodies (mAbs) camrelizumab, sintilimab, and tislelizumab, and programmed cell death-ligand 1 (PD-L1) mAb sugemalimab, which have made huge breakthrough in recent years. Some other investigational innovative drug also demonstrated promising efficacy and acceptable safety profiles. Results from clinical studies on these China innovative drugs have led to changes in clinical practice guidelines and considerably improved the outcomes for patients with lung cancer. Thus, in this review, we aim to provide further insight into the clinical development and achievement of China innovative anti-lung cancer drugs.

Holistic immunomodulation for small cell lung cancer

Small cell lung cancer (SCLC) is characterized by a high mortality rate, rapid growth, and early metastasis, which lead to a poor prognosis. Moreover, limited clinical treatment options further lower the survival rate of patients. Therefore, novel technology and agents are urgently required to enhance clinical efficacy. In this review, from a holistic perspective, we summarized the therapeutic targets, agents and strategies with the most potential for treating SCLC, including chimeric antigen receptor (CAR) T therapy, immunomodulating antibodies, traditional Chinese medicines (TCMs), and the microbiota, which have been found recently to improve the clinical outcomes and prognosis of SCLC. Multiomics technologies can be integrated to develop effective diagnostic methods and identify new targets for new drug discovery in SCLC. We discussed in depth the feasibility, potential, and challenges of these new strategies, as well as their combinational treatments, which may provide promising alternatives for enhancing the clinical efficacy of SCLC in the future.

The role of Hedgehog and Notch signaling pathway in cancer

Notch and Hedgehog signaling are involved in cancer biology and pathology, including the maintenance of tumor cell proliferation, cancer stem-like cells, and the tumor microenvironment. Given the complexity of Notch signaling in tumors, its role as both a tumor promoter and suppressor, and the crosstalk between pathways, the goal of developing clinically safe, effective, tumor-specific Notch-targeted drugs has remained intractable. Drugs developed against the Hedgehog signaling pathway have affirmed definitive therapeutic effects in basal cell carcinoma; however, in some contexts, the challenges of tumor resistance and recurrence leap to the forefront. The efficacy is very limited for other tumor types. In recent years, we have witnessed an exponential increase in the investigation and recognition of the critical roles of the Notch and Hedgehog signaling pathways in cancers, and the crosstalk between these pathways has vast space and value to explore. A series of clinical trials targeting signaling have been launched continually. In this review, we introduce current advances in the understanding of Notch and Hedgehog signaling and the crosstalk between pathways in specific tumor cell populations and microenvironments. Moreover, we also discuss the potential of targeting Notch and Hedgehog for cancer therapy, intending to promote the leap from bench to bedside.

Mechanistic insight into the repair of C8-linked pyrrolobenzodiazepine monomer-mediated DNA damage

Pyrrolobenzodiazepines (PBDs) are naturally occurring DNA binding compounds that possess anti-tumor and anti-bacterial activity. Chemical modifications of PBDs can result in improved DNA binding, sequence specificity and enhanced efficacy. More recently, synthetic PBD monomers have shown promise as payloads for antibody drug conjugates and anti-bacterial agents. The precise mechanism of action of these PBD monomers and their role in causing DNA damage remains to be elucidated. Here we characterized the damage-inducing potential of two C8-linked PBD bi-aryl monomers in Caulobacter crescentus and investigated the strategies employed by cells to repair the same. We show that these compounds cause DNA damage and efficiently kill bacteria, in a manner comparable to the extensively used DNA cross-linking agent mitomycin-C (MMC). However, in stark contrast to MMC which employs a mutagenic lesion tolerance pathway, we implicate essential functions for error-free mechanisms in repairing PBD monomer-mediated damage. We find that survival is severely compromised in cells lacking nucleotide excision repair and to a lesser extent, in cells with impaired recombination-based repair. Loss of nucleotide excision repair leads to significant increase in double-strand breaks, underscoring the critical role of this pathway in mediating repair of PBD-induced DNA lesions. Together, our study provides comprehensive insights into how mono-alkylating DNA-targeting therapeutic compounds like PBD monomers challenge cell growth, and identifies the specific mechanisms employed by the cell to counter the same.

Harnessing DLL3 inhibition: From old promises to new therapeutic horizons

Small-cell lung cancer (SCLC) is an aggressive neuroendocrine tumor with a high relapse rate, limited therapeutic options, and poor prognosis. The combination of chemotherapy and immune-checkpoint inhibitors brings a new therapeutic era, although the lack of predictive biomarkers of response reduces the efficacy of applying the treatment to the entire population of patients with SCLC. The lack of treatments able to bind to a specific target has always been a substantial difference to the non-small cell lung cancer (NSCLC) counterpart. Delta-like canonical Notch ligand 3 is a protein frequently overexpressed in SCLC and is therefore being explored as a potentially promising therapeutic target in high-grade neuroendocrine lung cancer. In this article, we critically review the activity and efficacy of old DLL3 inhibitors antibody-drug conjugate (ADC) and their failures through new compounds and their possible applications in clinical practice, with a focus on new molecular classification of SCLC.

Preparation of Triptolide Nano Drug Delivery System and Its Antitumor Activity In-Vitro

Triptolide (as an effective antitumor drug) is limited in clinical application because of its poor solubility and absorption in-vivo. Herein, we prepared folic acid modified polymer micelles to encapsulate triptolide and enhance its biologicalavailability coupled with antitumor effect. We prepared nano-micelles of triptolide through thin lipid film hydrational method. Physical properties and in vitro release characterization of Fol-Plla-cl-Peg-Plla-cl-Tmicelles were evaluated, while bioavailability of the formulation in rats was investigated. Tumor targeting potential of micelles was determined by observing the uptake of A549 cells. In-Vitro antitumor activity of micelles and free triptolide (API) was investigated with MTT assay. The prepared polymer material exhibited no cytotoxicity. The particle size distribution of Fol-Plla-cl-Peg-Plla-cl-T micelles was uniform and small, with good stability and high efficiency of entrapment. Triptolide In-Vitro release from micelles demonstrated slow and continuous released for 24 h. Compared with API, the half-life of micelles was prolonged, whilst its bioavailability in-vivo was increased by about 6.35 times. More importantly, Fol-Plla-cl-Peg-Plla-cl-T micelles significantly improved the antitumor activity of triptolide and showed good tumor targeting potential. Fol-Plla-cl-Peg-Plla-cl-T micelles could improve the bioavailability and antitumor activity of triptolide, amid demonstration of good tumor targeting and high safety.

DLL3 as an Emerging Target for the Treatment of Neuroendocrine Neoplasms

INTRODUCTION

Neuroendocrine neoplasms (NEN) are heterogeneous malignancies that can arise at almost any anatomical site and are classified as biologically distinct well-differentiated neuroendocrine tumors (NET) and poorly differentiated neuroendocrine carcinomas (NEC). Current systemic therapies for advanced disease, including targeted therapies, chemotherapy, and immunotherapy, are associated with limited duration of response. New therapeutic targets are needed. One promising target is delta-like ligand 3 (DLL3), an inhibitory ligand of the Notch receptor whose overexpression on the surface of NEN is associated with tumorigenesis.

METHODS

This article is a narrative review that highlights the role of DLL3 in NEN progression and prognosis, the potential for therapeutic targeting of DLL3, and ongoing studies of DLL3-targeting therapies. Classification, incidence, pathogenesis, and current management of NEN are reviewed to provide biological context and illustrate the unmet clinical needs.

DISCUSSION

DLL3 is overexpressed in many NENs, implicated in tumor progression, and is typically associated with poor clinical outcomes, particularly in patients with NEC. Targeted therapies using DLL3 as a homing beacon for cytotoxic activity mediated via several different mechanisms (eg, antibody-drug conjugates, T-cell engager molecules, CAR-Ts) have shown promising clinical activity in small-cell lung cancer (SCLC). DLL3 may be a clinically actionable target across NEN.

CONCLUSIONS

Current treatment options for NEN do not provide sustained responses. DLL3 is expressed on the cell surface of many NEN types and is associated with poor clinical outcomes. Initial clinical studies targeting DLL3 therapeutically in SCLC have been promising, and additional studies are expanding this approach to the broader group of NEN.

[Current Progress and Future Developments of Antibody Drug Conjugates in Lung Cancer]

Antibody drug conjugates (ADCs) are a novel class of anti-cancer drugs, which combined the specificity of monoclonal antibodies with the cytotoxic palyload via the linkers. Many ADCs have not only verified impressive activity in a variety of cancers, including breast cancer and hematological system tumors, but also in lung cancer. The aim of this study was to provide informations for practice by summarizing the mechanism of action, clinical application and problems and challenges of ADCs.
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Efficacy, Tolerability, and Pharmacokinetic Studies of Antibody-Drug Conjugates Containing a Low-Potency Pyrrolobenzodiazepine Dimer

Antibody-drug conjugate (ADC) research has typically focused on the release of highly potent cytotoxic agents to achieve antitumor efficacy. However, recently approved ADCs trastuzumab deruxtecan and sacituzumab govitecan release lower-potency topoisomerase inhibitors. This has prompted interest in ADCs that release lower-potency cytotoxic drugs to potentially enhance therapeutic index and reduce unwanted toxicity. Pyrrolobenzodiazepine (PBD) dimer ADCs have been widely investigated in human clinical trials, which have focused on high-potency PBDs. In this study, we evaluated five ADCs that release the low-potency PBD dimer SG3650. The relatively low cLogD for this agent facilitated higher drug-to-antibody ratio (DAR) conjugation without the need for antibody engineering or functionalization of the drug. The rank order of potency for DAR 2 site-specific ADCs (conjugated at the C239i position) matched the order for the corresponding free drugs in vitro. Despite free drug SG3650 being inactive in vivo, the DAR 2 ADCs derived from the corresponding drug-linker SG3584 showed antitumor efficacy in solid (anti-HER2) and hematological (anti-CD22) xenograft models. Antitumor activity could be enhanced by conjugating SG3584 to trastuzumab at higher DARs of 4 and 8 and by adjusting dosing and schedule. Higher-DAR conjugates were stable and displayed good rat pharmacokinetic profiles as measured by ELISA and LC-MS/MS. A single intravenous dose of isotype control SG3584 DAR 2 ADC resulted in no mortality in rats or monkeys at doses of up to 25 and 30 mg/kg, respectively. These findings suggest that further investigations of low-potency PBD dimers in ADCs that target hematological and solid tumors are warranted.

Delta-like ligand 3-targeted radioimmunotherapy for neuroendocrine prostate cancer

Neuroendocrine prostate cancer (NEPC) is a lethal subtype of prostate cancer with limited meaningful treatment options. NEPC lesions uniquely express delta-like ligand 3 (DLL3) on their cell surface. Taking advantage of DLL3 overexpression, we developed and evaluated lutetium-177 (177Lu)-labeled DLL3-targeting antibody SC16 (177Lu-DTPA-SC16) as a treatment for NEPC. SC16 was functionalized with DTPA-CHX-A" chelator and radiolabeled with 177Lu to produce 177Lu-DTPA-SC16. Specificity and selectivity of 177Lu-DTPA-SC16 were evaluated in vitro and in vivo using NCI-H660 (NEPC, DLL3-positive) and DU145 (adenocarcinoma, DLL3-negative) cells and xenografts. Dose-dependent treatment efficacy and specificity of 177Lu-DTPA-SC16 radionuclide therapy were evaluated in H660 and DU145 xenograft-bearing mice. Safety of the agent was assessed by monitoring hematologic parameters. 177Lu-DTPA-SC16 showed high tumor uptake and specificity in H660 xenografts, with minimal uptake in DU145 xenografts. At all three tested doses of 177Lu-DTPA-SC16 (4.63, 9.25, and 27.75 MBq/mouse), complete responses were observed in H660-bearing mice; 9.25 and 27.75 MBq/mouse doses were curative. Even the lowest tested dose proved curative in five (63%) of eight mice, and recurring tumors could be successfully re-treated at the same dose to achieve complete responses. In DU145 xenografts, 177Lu-DTPA-SC16 therapy did not inhibit tumor growth. Platelets and hematocrit transiently dropped, reaching nadir at 2 to 3 wk. This was out of range only in the highest-dose cohort and quickly recovered to normal range by week 4. Weight loss was observed only in the highest-dose cohort. Therefore, our data demonstrate that 177Lu-DTPA-SC16 is a potent and safe radioimmunotherapeutic agent for testing in humans with NEPC.

Improving the efficacy of immunotherapy in small cell lung cancer: Leveraging recent scientific discoveries and tumor-specific antigens

Small cell lung cancer (SCLC) is an aggressive neuroendocrine neoplasm with poor survival outcomes and little change to treatment standards over decades. SCLC is associated with heavy tobacco exposure and a high rate of somatic mutations in tumor cells, leading to hope that immune checkpoint inhibitors would dramatically reshape the treatment landscape of SCLC. Instead, immune checkpoint inhibitors have led to real but modest gains in outcomes, with only a small minority of patients deriving more durable benefit. Furthermore, biomarkers of ICI efficacy that have succeeded in other tumor types have not been validated in SCLC. However, recent research advances have suggested that epigenetic heterogeneity and plasticity play especially key roles in SCLC biology. Leveraging this emerging perspective, a new slate of candidate biomarkers of immune checkpoint inhibitor benefit have been described, and the novel treatment strategies combining rational epigenetic perturbation with immune checkpoint inhibitors are being developed. Finally, other immunotherapy strategies targeting SCLC-specific mechanisms are being tested. Together, these developments may lead to a second generation of much more efficacious immunotherapies in SCLC.

[Small cell lung cancer-Established standards and new approaches]

BACKGROUND

Although the treatment and prognosis of many solid tumor types in the metastatic situation could be considerably improved during the last decade, for a long time no significant progress in the treatment of small cell lung cancer (SCLC) could be achieved.

OBJECTIVE

The aim of this article is to describe the current treatment standard for SCLC and to discuss potential approaches for further improvement.

METHODS

A selective literature search was carried out in PubMed and abstract lists of relevant conferences.

RESULTS

Given the recent approval of two immunochemotherapy regimens based on the combination of anti-PD-L1 antibodies with platinum-etoposide, the therapeutic standard in the first line treatment of metastasized SCLC has finally been improved for the first time in three decades; however, the overall survival benefit has been modest with an improvement of just 2-3 months. In advanced lines of treatment no new approaches could so far show improved outcome compared with established chemotherapy protocols, such as topotecan and combinations of anthracycline, cyclophosphamide and vincristine. The slow progress in SCLC compared to non-SCLC, has been attributed to the complex biology, the exceptionally high proliferation rate and rapid development of resistance to chemotherapy. Increasing knowledge on the molecular and immunological principles of SCLC is increasingly opening up novel treatment approaches.

CONCLUSION

There has finally been a slow but clinically meaningful progress in the treatment of SCLC. Patients should be included in clinical trials at the latest after second line treatment, in order to accelerate the speed of the expansion of treatment options.

Evaluation of the DLL3-targeting antibody-drug conjugate rovalpituzumab tesirine in preclinical models of neuroblastoma

Neuroblastomas have neuroendocrine features and often show similar gene expression patterns to small cell lung cancer including high expression of delta-like ligand 3 (DLL3). Here we determine the efficacy of rovalpituzumab tesirine (Rova-T), an antibody drug conjugated (ADC) with a pyrrolobenzodiazepine (PBD) dimer toxin targeting DLL3, in preclinical models of human neuroblastoma. We evaluated DLL3 expression in RNA sequencing data sets and performed immunohistochemistry (IHC) on neuroblastoma patient derived xenograft (PDX), human neuroblastoma primary tumor and normal childhood tissue microarrays (TMAs). We then evaluated the activity of Rova-T against 11 neuroblastoma PDX models using varying doses and schedules and compared anti-tumor activity to expression levels. DLL3 mRNA was differentially overexpressed in neuroblastoma at comparable levels to small cell lung cancer, as well as Wilms and rhabdoid tumors. DLL3 protein was robustly expressed across the neuroblastoma PDX array, but membranous staining was variable. The human neuroblastoma array, however, showed staining in only 44% of cases, whereas no significant staining was observed in the normal childhood tissue array. Rova-T showed a clear dose response effect across the 11 models tested, with a single dose inducing a complete or partial response in 3/11 and stable disease in another 3/11 models. No overt signs of toxicity were observed, and there was no treatment-related mortality. Strong membranous staining was necessary, but not sufficient, for anti-tumor activity. Rova-T has activity in a subset of neuroblastoma preclinical models, but heterogeneous expression in these models and the near absence of expression seen in human tumors suggests that any DLL3-targeting clinical trial should be only performed with a robust companion diagnostic to evaluate DLL3 expression for patient selection.

New perspectives in the management of small cell lung cancer

The treatment of small cell lung cancer (SCLC) is a challenge for all specialists involved. New treatments have been added to the therapeutic armamentarium in recent months, but efforts must continue to improve both survival and quality of life. Advances in surgery and radiotherapy have resulted in prolonged survival times and fewer complications, while more careful patient selection has led to increased staging accuracy. Developments in the field of systemic therapy have resulted in changes to clinical guidelines and the management of patients with advanced disease, mainly with the introduction of immunotherapy. In this article, we describe recent improvements in the management of patients with SCLC, review current treatments, and discuss future lines of research.

[DNA Damage Repair System and Antineoplastic Agents in Lung Cancer]

DNA damage repair (DDR) system plays an important role in maintaining of genomic stability. Accumulation of DNA lesions or deficiency of DDR system could drive tumorigenesis as well as promote tumor progression; meanwhile, they could also provide therapeutic opportunities and targets. Of all the antineoplastic agents of lung cancers, many of them targeted or were associated with DNA damage and repair pathways, such as chemotherapies and antibody-drug conjugates which were designed directly causing DNA damages, targeted drugs inhibiting DNA repair pathways, and immune-checkpoint inhibitors. In this review, we described the role of DNA damage and repair pathways in antitumor activity of the above agents, as well as summarized the application and clinical investigations of these antineoplastic agents in lung cancers, in order to provide more information for exploring precision and effective strategies for the treatment of lung cancer based on the mechanism of DNA damage and repair.
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Emerging trends in immunotoxin targeting cancer stem cells

Cancer stem cells (CSCs) are self-renewing multipotent cells that play a vital role in the development of cancer drug resistance conditions. Various therapies like conventional, targeted, and radiotherapies have been broadly used in targeting and killing these CSCs. Among these, targeted therapy selectively targets CSCs and leads to overcoming disease recurrence conditions in cancer patients. Immunotoxins (ITs) are protein-based therapeutics with selective targeting capabilities. These chimeric molecules are composed of two functional moieties, i.e., a targeting moiety for cell surface binding and a toxin moiety that induces the programmed cell death upon internalization. Several ITs have been constructed recently, and their preclinical and clinical efficacies have been evaluated. In this review, we comprehensively discussed the recent preclinical and clinical advances as well as significant challenges in ITs targeting CSCs, which might reduce the burden of drug resistance conditions in cancer patients from bench to bedside.

Strategies to mitigate the on- and off-target toxicities of recombinant immunotoxins: an antibody engineering perspective

Targeted cancer therapies using immunotoxins has achieved remarkable efficacies in hematological malignancies. However, the clinical development of immunotoxins is also faced with many challenges like anti-drug antibodies and dose-limiting toxicity issues. Such a poor efficacy/safety ratio is also the major hurdle in the research and development of antibody-drug conjugates. From an antibody engineering perspective, various strategies were summarized/proposed to tackle the notorious on target off tumor toxicity issues, including passive strategy (XTENylation of immunotoxins) and active strategies (modulating the affinity and valency of the targeting moiety of immunotoxins, conditionally activating immunotoxins in the tumor microenvironments and reconstituting split toxin to reduce systemic toxicity etc.). By modulating the functional characteristics of the targeting moiety and the toxic moiety of immunotoxins, selective tumor targeting can be augmented while sparing the healthy cells in normal tissues expressing the same target of interest. If successful, the improved therapeutic index will likely help to address the dose-limiting toxicities commonly observed in the clinical trials of various immunotoxins.

Current status and future perspectives of immune checkpoint inhibitors in extensive-stage small cell lung cancer

Small-cell lung cancer (SCLC) is a type of neuroendocrine neoplasms with high aggressiveness and poor prognosis. Chemotherapy has been the standard first-line therapy for SCLC over the past several decades. In recent years, results of randomized phase III CASPIAN and IMpower-133 trials indicated that the combination of immune checkpoint inhibitors (ICIs) with platinum-etoposide chemotherapy improved the overall survival (OS) of patients with extensive stage small-cell lung cancer (ES-SCLC), which has transformed the treatment model for ES-SCLC. ICIs combined with chemotherapy has become the new first-line standard treatment of ES-SCLC with the latest research results from CASPIAN and ASTRUM-005 studies. This review summarizes the recent progress of ICIs in the treatment of ES-SCLC and expounds the mode and efficacy of immunotherapy for ES-SCLC. Future research focused on exploring basic SCLC biology and identifying novel predictive biomarkers in response to ICIs in ES-SCLC is essential. Double-ICIs treatment strategies, bispecific antibodies, and ICIs combined with other therapies, such as chemotherapy, radiotherapy, and targeted therapy, represent a new modality and show great promise for the treatment of ES-SCLC, which should achieve greater therapeutic effects through multiple synergistic mechanisms.

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.

Delta-like ligand 3 (DLL3): an attractive actionable target in tumors with neuroendocrine origin

INTRODUCTION

Neuroendocrine carcinomas are very aggressive tumors with few treatment options. DLL3 seems to be an optimal target for therapeutic intervention, as it is expressed mainly on the membrane of tumor cells with neuroendocrine origin.

AREAS COVERED

In this article, we outline the preclinical and clinical studies published in the last years on DLL3 in neuroendocrine neoplasm, above all of lung origin. Furthermore, we review the current literature on the interaction between DLL3 and the tumor microenvironment.

EXPERT OPINION

Several DLL3-targeting strategies have been proposed in the last years with mixed results. Understanding the influence of DLL3 on the tumor (immune) microenvironment and developing adoptive therapies directed against this optimal target might represent the key strategy. Building on the clinical data obtained so far, future trials on in vivo diagnostic tools for predictive purpose and new specific therapies are needed.

Radioimmunotherapy Targeting Delta-like Ligand 3 in Small Cell Lung Cancer Exhibits Antitumor Efficacy with Low Toxicity

PURPOSE

Small cell lung cancer (SCLC) is an exceptionally lethal form of lung cancer with limited treatment options. Delta-like ligand 3 (DLL3) is an attractive therapeutic target as surface expression is almost exclusive to tumor cells.

EXPERIMENTAL DESIGN

We radiolabeled the anti-DLL3 mAb SC16 with the therapeutic radioisotope, Lutetium-177. [177Lu]Lu-DTPA-CHX-A"-SC16 binds to DLL3 on SCLC cells and delivers targeted radiotherapy while minimizing radiation to healthy tissue.

RESULTS

[177Lu]Lu-DTPA-CHX-A"-SC16 demonstrated high tumor uptake with DLL3-target specificity in tumor xenografts. Dosimetry analyses of biodistribution studies suggested that the blood and liver were most at risk for toxicity from treatment with high doses of [177Lu]Lu-DTPA-CHX-A"-SC16. In the radioresistant NCI-H82 model, survival studies showed that 500 μCi and 750 μCi doses of [177Lu]Lu-DTPA-CHX-A"-SC16 led to prolonged survival over controls, and 3 of the 8 mice that received high doses of [177Lu]Lu-DTPA-CHX-A"-SC16 had pathologically confirmed complete responses (CR). In the patient-derived xenograft model Lu149, all doses of [177Lu]Lu-DTPA-CHX-A"-SC16 markedly prolonged survival. At the 250 μCi and 500 μCi doses, 5 of 10 and 7 of 9 mice demonstrated pathologically confirmed CRs, respectively. Four of 10 mice that received 750 μCi of [177Lu]Lu-DTPA-CHX-A"-SC16 demonstrated petechiae severe enough to warrant euthanasia, but the remaining 6 mice demonstrated pathologically confirmed CRs. IHC on residual tissues from partial responses confirmed retained DLL3 expression. Hematologic toxicity was dose-dependent and transient, with full recovery within 4 weeks. Hepatotoxicity was not observed.

CONCLUSIONS

Together, the compelling antitumor efficacy, pathologic CRs, and mild and transient toxicity profile demonstrate strong potential for clinical translation of [177Lu]Lu-DTPA-CHX-A"-SC16.

Notch signaling pathway: architecture, disease, and therapeutics

The NOTCH gene was identified approximately 110 years ago. Classical studies have revealed that NOTCH signaling is an evolutionarily conserved pathway. NOTCH receptors undergo three cleavages and translocate into the nucleus to regulate the transcription of target genes. NOTCH signaling deeply participates in the development and homeostasis of multiple tissues and organs, the aberration of which results in cancerous and noncancerous diseases. However, recent studies indicate that the outcomes of NOTCH signaling are changeable and highly dependent on context. In terms of cancers, NOTCH signaling can both promote and inhibit tumor development in various types of cancer. The overall performance of NOTCH-targeted therapies in clinical trials has failed to meet expectations. Additionally, NOTCH mutation has been proposed as a predictive biomarker for immune checkpoint blockade therapy in many cancers. Collectively, the NOTCH pathway needs to be integrally assessed with new perspectives to inspire discoveries and applications. In this review, we focus on both classical and the latest findings related to NOTCH signaling to illustrate the history, architecture, regulatory mechanisms, contributions to physiological development, related diseases, and therapeutic applications of the NOTCH pathway. The contributions of NOTCH signaling to the tumor immune microenvironment and cancer immunotherapy are also highlighted. We hope this review will help not only beginners but also experts to systematically and thoroughly understand the NOTCH signaling pathway.

Killing SCLC: insights into how to target a shapeshifting tumor

Small cell lung cancer (SCLC) is a rapidly growing, highly metastatic, and relatively immune-cold lung cancer subtype. Historically viewed in the laboratory and clinic as a single disease, new discoveries suggest that SCLC comprises multiple molecular subsets. Expression of MYC family members and lineage-related transcription factors ASCL1, NEUROD1, and POU2F3 (and, in some studies, YAP1) define unique molecular states that have been associated with distinct responses to a variety of therapies. However, SCLC tumors exhibit a high degree of intratumoral heterogeneity, with recent studies suggesting the existence of tumor cell plasticity and phenotypic switching between subtype states. While SCLC plasticity is correlated with, and likely drives, therapeutic resistance, the mechanisms underlying this plasticity are still largely unknown. Subtype states are also associated with immune-related gene expression, which likely impacts response to immune checkpoint blockade and may reveal novel targets for alternative immunotherapeutic approaches. In this review, we synthesize recent discoveries on the mechanisms of SCLC plasticity and how these processes may impinge on antitumor immunity.

Antibody-Drug Conjugate Targets, Drugs and Linkers

Antibody-drug conjugates offer the possibility of directing powerful cytotoxic agents to a malignant tumor while sparing normal tissue. The challenge is to select an antibody target expressed exclusively or at highly elevated levels on the surface of tumor cells and either not all or at low levels on normal cells. The current review explores 78 targets that have been explored as antibody-drug conjugate targets. Some of these targets have been abandoned, 9 or more are the targets of FDA-approved drugs, and most remain active clinical interest. Antibody-drug conjugates require potent cytotoxic drug payloads, several of these small molecules are discussed, as are the linkers between the protein component and small molecule components of the conjugates. Finally, conclusions regarding the elements for the successful antibody-drug conjugate are discussed.

RESILIENT part 1: A phase 2 dose-exploration and dose-expansion study of second-line liposomal irinotecan in adults with small cell lung cancer

BACKGROUND

RESILIENT (NCT03088813) is a phase 2/3 study assessing the safety, tolerability, and efficacy of liposomal irinotecan monotherapy in patients with small cell lung cancer and disease progression on/after first-line platinum-based therapy. Here, we present results from RESILIENT part 1.

METHODS

This open-label, single-arm, safety run-in evaluation with dose-exploration and dose-expansion phases included patients ≥18 years old with Eastern Cooperative Oncology Group performance status of 0/1; those with asymptomatic central nervous system metastases were eligible. The primary objectives were to evaluate safety and tolerability and recommend a dose for further development. Efficacy end points were objective response rate (ORR), progression-free survival (PFS), and overall survival (OS).

RESULTS

During dose exploration, 5 patients received intravenous liposomal irinotecan at 85 mg/m² (deemed not tolerable; dose-limiting toxicity) and 12 patients received 70 mg/m² (deemed tolerable). During dose expansion, 13 additional patients received intravenous liposomal irinotecan at 70 mg/m² . Of these 25 patients (median age [range], 59.0 [48.0-73.0] years, 92.0% with metastatic disease), 10 experienced grade ≥3 treatment-related treatment-emergent adverse events (TEAEs), most commonly diarrhea (20.0%) and neutropenia (16.0%), and 3 had serious treatment-related TEAEs, of whom 2 died. ORR was 44.0% (95% confidence interval [CI]: 24.40-65.07; 1 complete response, 10 partial responses) and median (95% CI) PFS and OS were 3.98 (1.45-4.24) months and 8.08 (5.16-9.82) months, respectively.

CONCLUSION

Overall, no new safety signals were identified with liposomal irinotecan, and antitumor activity was promising. RESILIENT part 2, a randomized, controlled, phase 3 study of liposomal irinotecan versus topotecan, is ongoing.

LAY SUMMARY

Small cell lung cancer (SCLC) is an aggressive disease with few treatment options after platinum-based therapy. Administering 1 option, irinotecan, as a "liposomal" formulation, may extend drug exposure and improve outcomes. The RESILIENT part 1 trial assessed the safety and efficacy of liposomal irinotecan in 25 adults with SCLC after disease progression despite platinum-based therapy. No new safety concerns were reported. The most common moderate-to-severe side effects were diarrhea (20% of patients) and neutropenia (16%). Tumors responded to treatment in 44% of patients. Average survival was 8.08 months, and time to disease progression was 3.98 months. Liposomal irinotecan trials are ongoing.

Chimeric antigen receptor T cell therapy: challenges and opportunities in lung cancer

Chimeric antigen receptor (CAR) T-cell therapy has revolutionized the paradigm in hematological malignancies treatment, driving an ever-expanding number of basic research and clinical trials of genetically engineering T cells to treat solid tumors. CAR T-cell therapies based on the antibodies targeting Mesothelin, CEA, EGFR, EGFR, MUC1, DLL3, and emerging novel targets provide promising efficacy for lung cancer patients. However, clinical application of CAR T-cell therapy against lung cancer remains limited on account of physical and immune barriers, antigen escape and heterogeneity, on-target off-tumor toxicity, and many other reasons. Understanding the evolution of CAR structure and the generalizable requirements for manufacturing CAR T cells as well as the interplay between lung tumor immunology and CAR T cells will improve clinical translation of this therapeutic modality in lung cancer. In this review, we systematically summarize the latest advances in CAR T-cell therapy in lung cancer, focusing on the CAR structure, target antigens, challenges, and corresponding new strategies.

Therapeutic Modalities in Small Cell Lung Cancer: a paradigm shift after decades of quiescence

INTRODUCTION

Small cell lung cancer (SCLC) is known to be the most aggressive of all thoracic malignancies, notoriously known for its very poor prognosis. Platinum based chemotherapy has been the standard of care for decades. Despite years of research, no treatment novelties with significant impact on survival have been achieved until recently. The last few years have witnessed light at the end of the tunnel with immunotherapy proving to improve survival. Nevertheless, responses were not homogeneous in all subgroups, and finding who would best benefit from treatment remains unanswered. Multiple limitations exist, and the quest for optimal biomarkers seemed unfruitful until the discovery of different SCLC phenotypes.

AREAS COVERED

In this review, the authors briefly discuss SCLC phenotypes and biomarker assays. Then, the authors continue with the main trials of SCLC treatment using chemotherapy, immunotherapy and targeted treatment in the front-line or subsequent line settings.

EXPERT OPINION

Research has been extensively implemented to better understand the biology of SCLC, and test for the optimal use of immunotherapy in patients with SCLC, as well as to enhance responses via possible combinations. Targeted mechanisms of action have also been attempted; yet no solid proof of efficacy has been established.

Antibody–Drug Conjugates as an Emerging Therapy in Oncodermatology

Simple Summary

Currently, the therapeutic arsenal to fight cancers is extensive. Among these, antibody–drug conjugates (ADCs) consist in an antibody linked to a cytotoxic agent, allowing a specific delivery to tumor cells. ADCs are an emerging class of therapeutics, with twelve FDA- and EMA-approved drugs for hematological and solid cancers. In recent years, tremendous progress has been observed in therapeutic approaches for advanced skin cancer patients. ADCs appear as an emerging therapeutic option in oncodermatology. After providing an overview of ADC design and development, the goal of this article is to review the potential ADC indications in the field of oncodermatology.

Abstract

Antibody–drug conjugates (ADCs) are an emerging class of therapeutics, with twelve FDA- and EMA-approved drugs for hematological and solid cancers. Such drugs consist in a monoclonal antibody linked to a cytotoxic agent, allowing a specific cytotoxicity to tumor cells. In recent years, tremendous progress has been observed in therapeutic approaches for advanced skin cancer patients. In this regard, targeted therapies (e.g., kinase inhibitors) or immune checkpoint-blocking antibodies outperformed conventional chemotherapy, with proven benefit to survival. Nevertheless, primary and acquired resistances as well as adverse events remain limitations of these therapies. Therefore, ADCs appear as an emerging therapeutic option in oncodermatology. After providing an overview of ADC design and development, the goal of this article is to review the potential ADC indications in the field of oncodermatology.

Effectiveness and Safety of Anlotinib Monotherapy for Patients with Extensive-stage Small-Cell Lung Cancer Who Progressed to Chemotherapy: A Real-world Exploratory Study

Background:

Anlotinib demonstrated promising efficacy for patients with extensive-stage small-cell lung cancer (ES-SCLC) in clinical trials. However, the real-world evidence of anlotinib monotherapy in ES-SCLC was still limited currently. Therefore, present study was to investigate the effectiveness and safety of anlotinib for patients with ES-SCLC who progressed to chemotherapy in real-world and the potential biomarker during anlotinib monotherapy.

Methods:

A total of 89 patients with ES-SCLC who failed the previous chemotherapy treatment were recruited. All the patients were administered with anlotinib monotherapy. Demographic data of the patients were collected; effectiveness and safety profile during anlotinib monotherapy were documented through electronic medical record system in the hospital. Progression-free survival (PFS) and overall survival (OS) were presented using Kaplan-Meier survival curves and multivariate analysis was adjusted by Cox regression analysis.

Results:

All the 89 patients with ES-SCLC who progressed to chemotherapy were available for the assessment of effectiveness and safety profile. Best overall response indicated that partial response was observed in 6 patients (6.7%), stable disease was noted in 61 patients (68.5%), and progressive disease was found in 22 patients (24.7%). Therefore, the objective response rate (ORR) and disease control rate (DCR) of the 89 patients with ES-SCLC was 6.7% (95% confidence interval [CI]: 2.5%-14.1%) and 75.3% (95% CI: 65.0%-83.8%), respectively. The prognostic data suggested that the median PFS of the 89 patients was 3.1 months (95% CI: 2.10-4.10), and the median OS was 8.6 months (95% CI: 7.42-9.78). In addition, the most common adverse reactions of the patients who received anlotinib monotherapy were hypertension (34.8%), hand-foot syndrome (30.3%), fatigue (29.2%), loss of appetite (27.0%), and hematological toxicity (21.3%). Association analysis between biomarker (hypertension status) and prognosis indicated that the median PFS of patients with hypertension and patients with non-hypertension was 5.5 and 3.0 months, respectively (χ² = 4.64, P = .031). Furthermore, multivariate Cox analysis for PFS suggested that hypertension status was an independent factor for PFS (hazard ratio [HR] = 0.71, P = .035].

Conclusion:

Anlotinib monotherapy showed encouraging effectiveness and acceptable safety profile for patients with ES-SCLC in real world. Hypertension induced by anlotinib administration might be used as a potential biomarker to predict superior PFS for patients with ES-SCLC.

CAR NK-92 cells targeting DLL3 kill effectively small cell lung cancer cells in vitro and in vivo

Small cell lung cancer (SCLC) is characterized by a high relapse rate, drug tolerance, and limited treatment choices. Chimeric antigen receptor (CAR)-modified NK cells represent a promising immunotherapeutic modality for cancer treatment. However, their potential applications have not been explored in SCLC. Delta-like ligand 3 (DLL3) has been reported to be overexpressed in SCLC and may be a rational target for CAR NK immunotherapy. In this study, we developed DLL3-specific NK-92 cells and explored their potential in the treatment of SCLC. A coculture of DLL3⁺ SCLC cell lines with DLL3-CAR NK-92 cells exhibited significant in vitro cytotoxicity and cytokine production. DLL3-CAR NK-92 cells induced tumor regression in an H446-derived pulmonary metastasis tumor model under a good safety threshold. The potent antitumor activities of DLL3-CAR NK-92 cells were observed in subcutaneous tumor models of SCLC. Moreover, obvious tumor-infiltrated DLL3-CAR NK-92 cells were detected in DLL3⁺ SCLC xenografts. These findings indicate that DLL3-CAR NK-92 cells might be a potential strategy for the treatment of SCLC.

Clinical Activity and Safety of Anlotinib Combined with PD-1 Blockades for Patients with Previously Treated Small Cell Lung Cancer

Objective

Anlotinib was the standard monotherapy for patients with previously treated small cell lung cancer (SCLC) in recent years. Programmed cell death protein 1 (PD-1) blockade combined with antiangiogenic targeted drugs have proved to play a synergistic action for cancer treatment clinically. Consequently, the present study was to investigate the efficacy and safety of anlotinib combined with PD-1 blockades for patients with previously treated SCLC.

Methods

A total of 36 patients with SCLC who were treated with at least one previous systemic chemotherapy regimen participated in this study retrospectively. All the patients were administered with anlotinib plus PD-1 blockades therapy. Clinical activity was assessed according to the change of target lesion by imaging evidence and all the subjects were followed up regularly. Safety profiles were collected and documented during the treatment. Univariate analysis was carried out using Log rank test and multivariate analysis was adjusted by Cox regression analysis.

Results

All the 36 patients with previously treated SCLC were able to have their efficacy and safety profile evaluated. The best overall response of the combination regimen showed that complete response was observed in one patient, partial response was noted in 9 patients, stable disease was reported in 19 patients, progressive disease was seen in 7 patients. Therefore, the objective response rate (ORR) of the 36 patients was 27.8% (95% CI: 14.2-45.2%), disease control rate (DCR) was 80.6% (95% CI: 64.0-91.8%). Regarding the prognostic data, the median PFS and OS of the 36 patients was 4.6 months (95% CI: 3.13-6.07) and 9.3 months (95% CI: 3.30-15.30), respectively. The most common treatment-related adverse reactions were hypertension (52.8%), fatigue (47.2%), diarrhea (38.9%), hand and foot reaction (38.9%) and dermal toxicity (33.3%). Furthermore, multivariate Cox regression analysis for PFS indicated that ECOG performance status was an independent factor to predict PFS.

Conclusion

Anlotinib combined with PD-1 blockades regimen preliminarily demonstrated encouraging efficacy and tolerable safety for patients with previously treated SCLC. The conclusion should be validated in prospective clinical trials subsequently.

Antibody-drug conjugates: Resurgent anticancer agents with multi-targeted therapeutic potential

Antibody-drug conjugates (ADCs) constitute a relatively new group of anticancer agents, whose first appearance took place about two decades ago, but a renewed interest occurred in recent years, following the success of anti-cancer immunotherapy with monoclonal antibodies. Indeed, an ADC combines the selectivity of a monoclonal antibody with the cell killing properties of a chemotherapeutic agent (payload), joined together through an appropriate linker. The antibody moiety targets a specific cell surface antigen expressed by tumor cells and/or cells of the tumor microenvironment and acts as a carrier that delivers the cytotoxic payload within the tumor mass. Despite advantages in terms of selectivity and potency, the development of ADCs is not devoid of challenges, due to: i) low tumor selectivity when the target antigens are not exclusively expressed by cancer cells; ii) premature release of the cytotoxic drug into the bloodstream as a consequence of linker instability; iii) development of tumor resistance mechanisms to the payload. All these factors may result in lack of efficacy and/or in no safety improvement compared to unconjugated cytotoxic agents. Nevertheless, the development of antibodies engineered to remain inert until activated in the tumor (e.g., antibodies activated proteolytically after internalization or by the acidic conditions of the tumor microenvironment) together with the discovery of innovative targets and cytotoxic or immunomodulatory payloads, have allowed the design of next-generation ADCs that are expected to possess improved therapeutic properties. This review provides an overview of approved ADCs, with related advantages and limitations, and of novel targets exploited by ADCs that are presently under clinical investigation.

Comorbidities and mortality risk among extensive-stage small-cell lung cancer patients in mainland China: impacts of hypertension, type 2 diabetes mellitus, and chronic hepatitis B virus infection

The present study investigated the impact of major comorbidities, including hypertension, type 2 diabetes mellitus (T2DM), and chronic hepatitis B virus (HBV) infection, on the progression-free survival (PFS) and overall survival (OS) of extensive-stage small-cell lung cancer (ES-SCLC) patients in China. Patients having a pathologic diagnosis of ES-SCLC between 2009 and 2017 were enrolled and grouped according to their specific comorbidities. The PFS and OS for each group were evaluated using the Kaplan-Meier method and Cox proportional hazard models. In total, 632 patients were analyzed. The median PFS (mPFS) of these patients was 9 months [95% confidence interval (CI), 6-12 months]. The mPFS of patients without hypertension or T2DM was 9 months; conversely, it was significantly reduced for patients with hypertension [7 months (P < 0.0001)] or T2DM [5 months (P < 0.0001)]. However, mPFS was not significantly different between patients with and without HBV infection (P = 0.2936). A similar trend was observed for OS as well. Further multivariate analyses showed that the OS of patients with hypertension [hazard ratio (HR), 1.344; 95% CI, 1.073-1.683; P = 0.010] or T2DM (HR, 1.455; 95% CI, 1.134-1.868; P = 0.003) was significantly shorter than that of patients without these comorbidities. Accordingly, mortality risk was the highest in patients with concurrent hypertension and T2DM (HR, 1.665; 95% CI, 1.037-2.672; P = 0.00058). Our study found that hypertension and T2DM may be associated with a worse prognosis in ES-SCLC patients. Considerable attention should be paid to the accompanying anti-comorbidity therapies available for patients with ES-SCLC.

ASCL1 and DLL3 expressions and their clinicopathological implications in surgically resected pure small cell lung cancer: A study of 247 cases from the National Cancer Center of China

Objective

Methods

Results

Conclusion

Rovalpituzumab tesirine resistance: analysis of a corresponding small cell lung cancer and circulating tumor cell line pair

Small cell lung cancer (SCLC) is frequently found disseminated at first presentation and holds a poor prognosis due to emerging resistance to first-line platinum-based and second-line topotecan chemotherapy. The present investigation tested the antitumor activity of rovalpituzumab tesirine (ROVA-T), a cytotoxic anti-DLL3 drug conjugate, against two SCLC and a corresponding SCLC CTC cell line established from a ROVA-T-resistant patient to characterize the mechanism of recurrence. Two cell lines were established from an SCLC patient progressing under ROVA-T therapy and characterized with respect to chemosensitivity against this drug as well as against currently applied chemotherapeutics and for their delta-like 3 (DLL3) expression. The chemosensitivity assays demonstrate that most SCLC lines show IC50 values exceeding the ROVA-T in-vivo concentrations and that slow-growing cells and lines showing spheroidal growth or proliferation as corresponding circulating tumor cells (CTCs) exhibit higher resistance. Chemosensitivity of the cell lines is not correlated with DLL3 protein expression possibly due to toxicity of the free payload in tissue culture. The clinical trials and experimental results demonstrate that refractoriness to ROVA-T is linked to a low initial tumor expression of DLL3, loss of DLL3 expression, higher chemoresistance to ROVA-T and the putative formation of resistant spheroids by the SCLC cells.