TROP-2 directed antibody-drug conjugates (ADCs): The revolution of smart drug delivery in advanced non-small cell lung cancer (NSCLC)

Emerging molecular testing paradigms in non-small cell lung cancer management-current perspectives and recommendations

Advances in molecular testing and precision oncology have transformed the clinical management of lung cancer, especially non-small cell lung cancer, enhancing diagnosis, treatment, and outcomes. Practical guidelines offer insights into selecting appropriate biomarkers and assays, emphasizing the importance of comprehensive testing. However, real-world data reveal the underutilization of biomarker testing and consequently targeted therapies. Molecular testing often occurs late in diagnosis or not at all in clinical practice, leading to delayed or inadequate treatment. Enhancing precision requires adherence to best practices by all health care professionals involved, which can ultimately improve lung cancer patient outcomes. The future of precision oncology for lung cancer will likely involve a more personalized approach, starting increasingly from earlier disease settings, with novel and more complex targeted therapies, immunotherapies, and combination regimens, and relying on liquid biopsies, muti-detection advanced genomic technologies and data integration, with artificial intelligence as a central orchestrator. This review presents the currently known actionable mutations in lung cancer and new upcoming ones that are likely to enter clinical practice soon and provides an overview of established and emerging concepts in testing methodologies. Challenges are discussed and best practice recommendations are made that are relevant today, will continue to be relevant in the future, and are likely to be relevant for other cancer types too.

Noninvasive molecular imaging using anti-Trop-2 aptamer for targeted therapy of small cell lung cancer

Recent advancements in antibody-drug conjugates (ADCs) targeting trophoblast surface cell antigen 2 (Trop-2) have brought important progress in the field of targeted therapy. This progress also holds promise for the treatment of small cell lung cancer (SCLC) as anti-Trop-2 therapy appears to have a safe and effective clinical activity in metastatic SCLC patients. However, effective treatments of anti-Trop-2 ADCs rely on the comprehensive assessment of Trop-2 expression at the tumor sites, SCLC exhibits intratumoral heterogeneity, making the accurate acquisition of histological biopsies a challenge. To address this issue, we herein report the development of an anti-Trop-2 aptamer consisting of 76 bases is specifically bind to Trop-2-overexpressing SCLC cells. Further truncated anti-Trop-2 aptamer with 46 nucleotides also possesses excellent in vitro and in vivo binding affinity with Trop-2 antigens. After radiolabeling with gallium-68 radionuclide, an aptamer-based molecular imaging probe was successfully fabricated named [68Ga]Ga-NOTA-TRP-c. This imaging probe demonstrated effective and precise differentiation of Trop-2-positive tumors in both murine- and human-derived animal models, exhibiting favorable metabolic profiles. Furthermore, Trop-2-positive SCLC tumors recognized by anti-Trop-2 aptamer can be treated with anti-Trop-2 ADC sacituzumab govitecan (SG), either in vitro or in vivo. Importantly, SG induces DNA damage and cell apoptosis without affecting the expression of Trop-2 on the cell surface, which makes it possible to use anti-Trop-2 aptamer to monitor the expression of Trop-2 in SCLC. This study highlights the potential of aptamer-based molecular imaging and imaging-guided SG treatment as a promising option for targeted therapy in SCLC.

Evaluating the safety of antibody-drug conjugates in lung cancer: A systematic review and meta-analysis

BACKGROUND

Antibody-drug conjugates (ADC) have emerged as a promising treatment for lung cancer. However, their safety profile requires further analysis. This study assessed adverse events (AE) in patients with lung cancer treated with ADCs, with particular focus on differences in pathological types, therapeutic options, and drug components.

METHODS

Prospective trials from various databases up to June 11, 2024, that analyzed treatment-emergent AEs (TEAEs), treatment-related AEs (TRAEs), mortality, and drug discontinuation were identified. Incidence rates were pooled using a random effects model, and their corresponding 95% confidence intervals (CIs) were calculated.

RESULTS

The analysis included 28 studies with 3,127 participants. The pooled incidence of all-grade TEAEs and TRAEs was 98.9 % and 91.4 %, respectively, whereas that of grade ≥ 3 TEAEs and TRAEs was 65.9 % and 41.7 %, respectively. The gastrointestinal system was frequently involved, albeit predominantly in low grades. Hematological system involvement was prevalent in grade ≥ 3 AEs, with respiratory system disorders being more prevalent in severe AEs. Respiratory system disorders were the primary cause of death and drug discontinuation. Subgroup analyses revealed higher incidences of AEs in SCLC than in NSCLC, in combination therapies than in monotherapies, and in ADCs with cleavable linkers. ADCs targeting delta-like protein 3 or carrying pyrrolobenzodiazepine dimer as payloads exhibit higher incidences of grade ≥ 3 TEAEs than those targeting HER2.

CONCLUSION

Effective managing ADC toxicities is crucial in lung cancer treatment, with AE incidence and profiles varying by cancer pathology, treatment regimen, and ADC components. Close monitoring of symptoms associated with gastrointestinal, infection, and respiratory systems is essential. PROSPERO registration number: CRD42024546210.

Unlocking Natural Potential: Antibody-Drug Conjugates With Naturally Derived Payloads for Cancer Therapy

Natural compound-derived chemotherapies remain central to cancer treatment, however, they often cause off-target side effects that negatively impact patients' quality of life. In contrast, antibody-drug conjugates (ADCs) combine cytotoxic payloads with antibodies to specifically target cancer cells. Most approved and clinically investigated ADCs utilize naturally derived payloads, while those with conventional synthetic molecular payloads remain limited. This review focuses on approved ADCs that enhance the efficacy of naturally derived payloads by linking them with antibodies. We provide an overview of the core components of ADCs, their working mechanisms, and FDA-approved ADCs featuring naturally derived payloads, such as calicheamicin, camptothecin, dolastatin 10, maytansine, pyrrolbenzodiazepine (PBD), and the immunotoxin Pseudomonas exotoxin A. This review also explores recent clinical advancements aimed at broadening the therapeutic potential of ADCs, their applicability in treating heterogeneously composed tumors and their potential use beyond oncology. Additionally, this review highlights naturally derived payloads that are currently being clinically investigated but have not yet received approval. By summarizing the current landscape, this review provides insights into promising avenues for exploration and contributes to the refinement of treatment protocols for improved patient outcomes.

Treatment Patterns and Clinical Outcomes in Patients With EGFR-Mutated Non-Small-Cell Lung Cancer After Progression on Osimertinib

INTRODUCTION

For patients with advanced epidermal growth factor receptor (EGFR)-mutated non-small-cell lung cancer (NSCLC) who progress on first-line osimertinib, the optimal second-line treatment regimen after progression is not known. We sought to assess practice patterns and evaluate the association between different therapies and survival in patients with EGFR-mutated NSCLC following progression on first-line osimertinib.

METHODS

Retrospective cohort study of patients who received first-line treatment with osimertinib using a population-based, multicenter nationwide electronic health record-derived deidentified database.

RESULTS

We identified 2373 patients who received first-line osimertinib. The majority (n = 2279) received osimertinib monotherapy. A total of 538 patients received first-line osimertinib and had second-line treatment data available. Second-line treatment regimens were varied: 65% (n = 348) included chemotherapy, 37% (n = 197) included an immune checkpoint inhibitor (ICI), and 44% (n = 234) included an EGFR tyrosine kinase inhibitor (TKI). We then analyzed the 333 patients with performance status 0-2 who received chemotherapy with osimertinib (n = 107, 32%) versus chemotherapy without osimertinib (n = 226, 68%). The continuation of osimertinib with chemotherapy was associated with superior progression-free survival (PFS; median: 10.1 versus 5.9 months, Hazard Ratio [HR]: 0.48, 95% Confidence Interval [CI]: [0.34, 0.68], P < .001) and overall survival (OS; median: 17.0 versus 12.8 months, HR: 0.64, 95% CI: [0.44, 0.93], P = .018) compared to other chemotherapy approaches without osimertinib. This effect was most pronounced in patients with an EGFR exon 19 deletion.

CONCLUSIONS

Following progression on osimertinib, a wide variety of treatment regimens were used. The continuation of osimertinib with chemotherapy in the second line was associated with increased PFS and OS.

Immuno-PET/CT Imaging of Trop2 with [18F]AlF-RESCA-T4 Differentiates Lung Cancer from Inflammation

Immuno-PET/CT imaging, a branch of molecular imaging, can noninvasively and specifically visualize biomarker expression across the body. Trophoblast cell surface antigen 2 (Trop2) is a pan-cancer biomarker and plays a crucial role in tumorigenesis through multiple signaling pathways. The study aims to develop and translate novel Trop2 single-domain antibody (sdAb) tracers for clinical use. Methods: Two sdAbs (i.e., His-tagged T4 and His-tag-free RT4) are recombinantly expressed in Chinese hamster ovary cells. The purities and binding kinetics are determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis, high-performance liquid chromatography, and surface plasmon resonance assays. The AlF restrained complexing agent (RESCA) method is applied to develop 18F-labeled sdAb tracers ([18F]AlF-RESCA-T4 and [18F]AlF-RESCA-RT4), followed by thorough preclinical imaging and blocking studies on tumor-bearing mice and a pilot clinical trial evaluating the clinical imaging safety and feasibility of [18F]AlF-RESCA-T4 immuno-PET/CT. Results: [18F]AlF-RESCA-T4 and [18F]AlF-RESCA-RT4 possess high radiochemical purities. Preclinical imaging in the T3M-4 tumor model revealed prominent uptake (percentage injected dose/g) of [18F]AlF-RESCA-T4 (11.13 ± 1.53, n = 4) and [18F]AlF-RESCA-RT4 (8.83 ± 1.22, n = 4), which were significantly reduced by coinjection of unlabeled T4 and RT4 in blocking studies. The His-tag removal strategy further optimized the probe's in vivo pharmacokinetics and reduced renal radioactivity accumulation without significantly decreasing tumor uptake. In a pilot clinical trial, [18F]AlF-RESCA-T4 immuno-PET/CT showed promising potency in annotating Trop2 expression and differentiating tumors from inflammatory diseases such as tuberculosis. Conclusion: [18F]AlF-RESCA-T4 and [18F]AlF-RESCA-RT4 can specifically annotate Trop2 expression. Clinical [18F]AlF-RESCA-T4 immuno-PET/CT imaging can screen patients for Trop2-targeted therapies and differentiate lung inflammation from cancer.

Current Status and Future Prospects of TROP-2 ADCs in Lung Cancer Treatment

Lung cancer is the leading cause of mortality worldwide, and non-small cell lung cancer accounts for the majority of lung cancer cases. Chemotherapy and radiotherapy constitute the mainstays of lung cancer treatment; however, their associated side effects involving the kidneys, nervous system, gastrointestinal tract, and liver further add to dismal outcomes. The advent of antibody‒drug conjugates (ADCs) could change this situation. Trophoblast surface antigen 2 (TROP-2), a human trophoblast surface antigen, is a tumor-associated antigen that is expressed at low levels in normal tissues and is overexpressed in a variety of malignant tumors. The differential expression of the TROP-2 protein in a variety of tumors makes tumor immunotherapy with ADCs targeting TROP-2 a promising approach. Previous studies have shown that the expression of TROP-2 is related to the prognosis of patients with lung cancer and that TROP-2 expression is different across different histological types; however, research on TROP-2 and TROP-2 ADCs in patients with lung cancer is not comprehensive. The aims of this study were to review the mechanism of action and clinical efficacy of TROP-2 and related drugs in the treatment of lung cancer, to elucidate the prognostic value of TROP-2 in lung cancer, and to discuss the future prospects of TROP-2 ADCs to provide a reference for the precise treatment of lung cancer.

Intercellular adhesion molecule-1 (ICAM-1): From molecular functions to clinical applications in cancer investigation

Intercellular adhesion molecule-1 (ICAM-1) is a versatile molecule that plays a critical role in various physiological and pathological processes, particularly in tumor development where its impact is bidirectional. On the one hand, it augments the immune response by promoting immune cell migration, infiltration, and the formation of immunological synapses, thus facilitating potent antitumor effects. Simultaneously, it contributes to tumor immune evasion and influences metastasis by mediating transendothelial migration (TEM), epithelial-to-mesenchymal transition (EMT), and epigenetic modification of tumor cells. Despite its significant potential, the full clinical utility of ICAM-1 has yet to be fully realized. In this review, we thoroughly examine recent advancements in understanding the role of ICAM-1 in tumor development, its relevance in predicting therapeutic efficacy and prognosis, as well as the progress in clinical translational research on anti-ICAM-1-based therapies, encompassing including monoclonal antibodies, immunotherapy, antibody-drug conjugate (ADC), and conventional treatments. By shedding light on these innovative strategies, we aim to underscore ICAM-1's significance as a valuable and multifaceted target for cancer treatment, igniting enthusiasm for further research and facilitating translation into clinical applications.

Emerging pharmacotherapy trends in preventing and managing oral mucositis induced by chemoradiotherapy and targeted agents

INTRODUCTION

The introduction of targeted therapy and immunotherapy has tremendously changed the clinical outcomes and prognosis of cancer patients. Despite innovative pharmacological therapies and improved radiotherapy (RT) techniques, patients continue to suffer from side effects, of which oral mucositis (OM) is still the most impactful, especially for quality of life.

AREAS COVERED

We provide an overview of current advances in cancer pharmacotherapy and RT, in relation to their potential to cause OM, and of the less explored and more recent literature reports related to the best management of OM. We have analyzed natural/antioxidant agents, probiotics, mucosal protectants and healing coadjuvants, pharmacotherapies, immunomodulatory and anticancer agents, photobiomodulation and the impact of technology.

EXPERT OPINION

The discovery of more precise pathophysiologic mechanisms of CT and RT-induced OM has outlined that OM has a multifactorial origin, including direct effects, oxidative damage, upregulation of immunologic factors, and effects on oral flora. A persistent upregulated immune response, associated with factors related to patients' characteristics, may contribute to more severe and long-lasting OM. The goal is strategies to conjugate individual patient, disease, and therapy-related factors to guide OM prevention or treatment. Despite further high-quality research is warranted, the issue of prevention is paramount in future strategies.

TROP2 Is Associated with Primary Resistance to Immune Checkpoint Inhibition in Patients with Advanced Non-Small Cell Lung Cancer

PURPOSE

Mechanisms of primary resistance to inhibitors of the programmed cell death-1 (PD-1)/programmed death-ligand 1 (PD-L1) signaling axis in non-small cell lung cancer (NSCLC) are still poorly understood. While some studies suggest the involvement of trophoblast cell surface antigen 2 (TROP2) in modulating tumor cell resistance to therapeutic drugs, its specific role in the context of PD-1/PD-L1 axis blockade is not definitively established.

EXPERIMENTAL DESIGN

We performed high-throughput analysis of transcriptomic data from 891 NSCLC tumors from patients treated with either the PD-L1 inhibitor atezolizumab or chemotherapy in two large randomized clinical trials. To confirm our results at the protein level, we complemented this transcriptional approach by performing a multiplex immunofluorescence analysis of tumor tissue samples as well as a proteomic profiling of plasma.

RESULTS

We observed a significant association of TROP2 overexpression with worse progression-free survival and overall survival on PD-L1 blockade, independent of other prognostic factors. Importantly, we found increased TROP2 expression to be predictive of survival in patients treated with atezolizumab but not chemotherapy. TROP2 overexpression was associated with decreased T-cell infiltration. We confirmed these results at the proteomic level both on tumor tissue and in plasma.

CONCLUSIONS

Our results suggest an important contribution of TROP2 expression to the primary resistance to PD-L1 blockade in NSCLC. TROP2-biomarker-based strategy may be relevant in selecting patients with NSCLC who are more likely to benefit from a combination of immunotherapy and an anti-TROP2 agent.

Targeting HER3 to overcome EGFR TKI resistance in NSCLC

Receptor tyrosine kinases (RTKs) play a crucial role in cellular signaling and oncogenic progression. Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) have become the standard treatment for advanced non-small cell lung cancer (NSCLC) patients with EGFR-sensitizing mutations, but resistance frequently emerges between 10 to 14 months. A significant factor in this resistance is the role of human EGFR 3 (HER3), an EGFR family member. Despite its significance, effective targeting of HER3 is still developing. This review aims to bridge this gap by deeply examining HER3's pivotal contribution to EGFR TKI resistance and spotlighting emerging HER3-centered therapeutic avenues, including monoclonal antibodies (mAbs), TKIs, and antibody-drug conjugates (ADCs). Preliminary results indicate combining HER3-specific treatments with EGFR TKIs enhances antitumor effects, leading to an increased objective response rate (ORR) and prolonged overall survival (OS) in resistant cases. Embracing HER3-targeting therapies represents a transformative approach against EGFR TKI resistance and emphasizes the importance of further research to optimize patient stratification and understand resistance mechanisms.

TROP2-directed nanobody-drug conjugate elicited potent antitumor effect in pancreatic cancer

BACKGROUND

Pancreatic cancer is a highly aggressive malignancy with limited treatment options and a poor prognosis. Trophoblast cell surface antigen 2 (TROP2), a cell surface antigen overexpressed in the tumors of more than half of pancreatic cancer patients, has been identified as a potential target for antibody-drug conjugates (ADCs). Almost all reported TROP2-targeted ADCs are of the IgG type and have been poorly studied in pancreatic cancer. Here, we aimed to develop a novel nanobody-drug conjugate (NDC) targeting TROP2 for the treatment of pancreatic cancer.

RESULTS

In this study, we developed a novel TROP2-targeted NDC, HuNbTROP2-HSA-MMAE, for the treatment of TROP2-positive pancreatic cancer. HuNbTROP2-HSA-MMAE is characterized by the use of nanobodies against TROP2 and human serum albumin (HSA) and has a drug-antibody ratio of 1. HuNbTROP2-HSA-MMAE exhibited specific binding to TROP2 and was internalized into tumor cells with high endocytosis efficiency within 5 h, followed by intracellular translocation to lysosomes and release of MMAE to induce cell apoptosis in TROP2-positive pancreatic cancer cells through the caspase-3/9 pathway. In a xenograft model of pancreatic cancer, doses of 0.2 mg/kg and 1 mg/kg HuNbTROP2-HSA-MMAE demonstrated significant antitumor effects, and a dose of 5 mg/kg even eradicated the tumor.

CONCLUSION

HuNbTROP2-HSA-MMAE has desirable affinity, internalization efficiency and antitumor activity. It holds significant promise as a potential therapeutic option for the treatment of TROP2-positive pancreatic cancer.