Clinical Challenges of Immune Checkpoint Inhibitors

Monitoring melanoma immunotherapeutic efficacy through successive metabolic labeling and PD-L1-confined signal amplification based on membrane characteristics of the newly generated circulating tumor cells

Unlike conventional detection, monitoring membrane characteristics of circulating tumor cells (CTCs) within a specific time frame can effectively indicate tumor progression, yet the challenge lies in selectively isolating CTCs generated during this period and precisely identifying subtle progression-related changes. This study focuses on CTCs newly generated during melanoma immunotherapy, utilizing a strategic combination of tumor-specific glycometabolic engineering, phenotypic protein-confined biotinylation and lanthanide luminescence to enrich and detect these spatiotemporally specific CTCs. First, Ac4ManNAz-associated cellular glycometabolic engineering selectively developes azide groups on the membranes of these CTCs, providing clickable artificial tags to distinguish them from pre-existing CTCs and blood cells. Subsequently, Fe3O4/lip-DBCO nanoparticles enrichs this CTC population through efficient click chemistry, achieving a capture efficiency exceeding 90 % for various types of CTCs, regardless of their phenotype, tumor type or species. Following this, a PD-L1-confined biotinylation is adopted to generate a significant number of biotin moieties in close proximity to the membrane PD-L1 of the captured CTCs, resulting in a 9-fold increase in the number of active sites available for introducing detection signal sources, compared to traditional immunofluorescent labeling methods. Further introduction of streptavidin-functionalized europium (Eu)-lanthanide nanoparticles (EuNPs-SA) quantifies the captured CTCs in a time-resolved manner and assesses CTC-related therapeutic response, while eliminating interferences from background biological substances. Specifically, significant advancements in detection performance have enabled the assessment of immunotherapeutic efficacy within melanoma model. Notably, substantial differences in lanthanide luminescent signals between the treated and untreated groups p = 0.000149), with the observed trends closely correlating with treatment outcomes.

In situ non-canonical activation and sensitization of cGAS-STING pathway with manganese telluride nanosheets

Immune checkpoint blockade (ICB) has achieved encouraging outcome in various malignant tumors. However, the low immunogenicity and insufficient infiltration of T cells within tumors severely limit the curative effects. Herein, we reported synthesis and experimental evaluation of H2O2-responsive MnTe2 nanosheets (NSs) for improving anti-tumor immune responses. Within the tumor microenvironment characterized by high level of H2O2, the MnTe2 NSs were degraded to release Mn2+ and TeO42- which subsequently induced cellular endoplasmic reticulum (ER) stress and non-canonically activated the cGAS-STING pathway. Moreover, the cellular Mn2+ ions enhanced the sensitivity of cGAS-STING pathway and the maturation of dendritic cells (DCs) concurrently. Ultimately, the MnTe2 NSs exhibited favorable in vivo anti-tumor immune effects, especially in combination with PD-L1 checkpoint inhibitors. These findings provided compelling evidence for exploration and utilization of nanomedicine to leverage innate immune system for better tumor immunotherapy.

Radiomic Model Associated with Tumor Microenvironment Predicts Immunotherapy Response and Prognosis in Patients with Locoregionally Advanced Nasopharyngeal Carcinoma

Background: No robust biomarkers have been identified to predict the efficacy of programmed cell death protein 1 (PD-1) inhibitors in patients with locoregionally advanced nasopharyngeal carcinoma (LANPC). We aimed to develop radiomic models using pre-immunotherapy MRI to predict the response to PD-1 inhibitors and the patient prognosis. Methods: This study included 246 LANPC patients (training cohort, n = 117; external test cohort, n = 129) from 10 centers. The best-performing machine learning classifier was employed to create the radiomic models. A combined model was constructed by integrating clinical and radiomic data. A radiomic interpretability study was performed with whole slide images (WSIs) stained with hematoxylin and eosin (H&E) and immunohistochemistry (IHC). A total of 150 patient-level nuclear morphological features (NMFs) and 12 cell spatial distribution features (CSDFs) were extracted from WSIs. The correlation between the radiomic and pathological features was assessed using Spearman correlation analysis. Results: The radiomic model outperformed the clinical and combined models in predicting treatment response (area under the curve: 0.760 vs. 0.559 vs. 0.652). For overall survival estimation, the combined model performed comparably to the radiomic model but outperformed the clinical model (concordance index: 0.858 vs. 0.812 vs. 0.664). Six treatment response-related radiomic features correlated with 50 H&E-derived (146 pairs, |r|= 0.31 to 0.46) and 2 to 26 IHC-derived NMF, particularly for CD45RO (69 pairs, |r|= 0.31 to 0.48), CD8 (84, |r|= 0.30 to 0.59), PD-L1 (73, |r|= 0.32 to 0.48), and CD163 (53, |r| = 0.32 to 0.59). Eight prognostic radiomic features correlated with 11 H&E-derived (16 pairs, |r|= 0.48 to 0.61) and 2 to 31 IHC-derived NMF, particularly for PD-L1 (80 pairs, |r|= 0.44 to 0.64), CD45RO (65, |r|= 0.42 to 0.67), CD19 (35, |r|= 0.44 to 0.58), CD66b (61, |r| = 0.42 to 0.67), and FOXP3 (21, |r| = 0.41 to 0.71). In contrast, fewer CSDFs exhibited correlations with specific radiomic features. Conclusion: The radiomic model and combined model are feasible in predicting immunotherapy response and outcomes in LANPC patients. The radiology-pathology correlation suggests a potential biological basis for the predictive models.

Multifunctional Nanoplatform for Highly Accurate Profiling of Triple-Negative Breast Cancer-Derived Chemo- and Immunotherapy Resistance Exosomes

Triple-negative breast cancer (TNBC) is the most malignant breast cancer with a higher mortality rate, which is due to the lack of targeted therapies and the development of resistance to chemotherapy and immunotherapy. Since the ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1) (+) exosome promotes chemoresistance and the programmed cell death ligand-1 (PD-L1) (+) exosome plays a crucial role in immunotherapy resistance, there is an urgent need in clinics to explore strategies for the rapid profiling of UCH-L1(+) and PD-L1(+) exosomes from blood to predict chemo- and immunotherapy treatment outcomes. Herein, we develop a multifunctional nanoplatform using antibody-conjugated green- and red-emissive carbon quantum dots attached to cobalt ferrite (CoFe2O4) magnetic nanoparticles for the highly accurate profiling of TNBC-derived UCH-L1(+) and PD-L1(+) exosomes. Specifically, by employing multiple microscopic, spectroscopic, and SQUID magnetometer techniques, we show that the multifunctional nanoplatform exhibits good chemical stability, high photostability, strong photoluminescence quantum yield, excellent superparamagnetic behavior, and biocompatibility. Moreover, by leveraging strategically designed anti-UCH-L1 antibody-attached red luminescence (660 nm) magnetic nanoplatform and anti-PD-L1 antibody-attached green luminescence (530 nm) magnetic nanoplatform, the reported data demonstrate that the multifunctional nanoplatform has the capability for capturing and screening ∼100% UCH-L1(+) and PD-L1(+) exosomes selectively from infected whole-blood samples. Furthermore, we showcase the potential application for the screening of UCH-L1 (+) and PD-L1(+) exosomes simultaneously from whole blood, which indicates that the nanoplatform may be used for monitoring chemotherapeutic and immunotherapeutic resistance of cancer.

Comprehensive multi-omics analysis of histone acetylation modulators identifies ASH1L as a novel aggressive marker for osteosarcoma

BACKGROUND

Osteosarcoma, a highly malignant bone tumor prevalent in children and adolescents, continues to have poor long-term survival rates, particularly in metastatic cases. While histone acetylation dysregulation has been implicated in cancer progression, the role of histone acetylation modification-related proteins (HAMRPs) in osteosarcoma immune infiltration and prognosis remains unclear.

METHODS

The expression patterns, prognostic implications, and clinical correlations of HAMRPs in osteosarcoma were analyzed using the TARGET, GEO, TISCH, and HPA databases. The effectiveness of HAMRPs in predicting the immune landscape of osteosarcoma was confirmed using CIBERSORT, ssGSEA, and ESTIMATE algorithms. The study employed GSEA analysis, wound healing assay, Transwell, and western blot to explore the role and regulatory mechanism of the key gene ASH1L in osteosarcoma progression.

RESULTS

Two distinct histone acetylation modification patterns were identified, showing significant differences in survival, clinical features, and immune landscape. Comprehensive clinical correlation analysis and Kaplan-Meier analysis of all HAMRPs used for two subtypes revealed that higher ASH1L expression was found in metastatic osteosarcoma cases and indicated poorer survival outcomes. In vitro experiments confirmed that ASH1L promoted osteosarcoma metastasis and epithelial-mesenchymal transition via the AKT/mTOR pathway. Additionally, an ASH1L-derived risk model was developed to aid personalized clinical decisions.

CONCLUSIONS

This study elucidates the prognostic and immunological significance of HAMRPs and highlights ASH1L as a novel aggressive marker in osteosarcoma.

Mouse colorectal cancer organoids: Lessons from syngeneic and orthotopic transplantation systems

Colorectal cancer (CRC) organoids provide more accurate and tissue-relevant models compared to conventional two-dimensional cultured cell cultures. Mouse CRC organoids, in particular, offer unique advantages over their human counterparts, as they can be transplanted into immunocompetent mice. These syngeneic transplantation models create a robust system for studying cancer biology in the immunocompetent tumor microenvironment (TME). This article discusses the development and applications of these organoid systems, emphasizing their capacity to faithfully recapitulate in vivo tumor progression, metastasis, and the immune landscape.

Immune Checkpoint Inhibitors and Immunosuppressive Tumor Microenvironment: Current Challenges and Strategies to Overcome Resistance

Immune checkpoint inhibitors (ICIs) are shown to improve cancer treatment effectiveness by boosting the immune system of the patient. Nevertheless, the unique and highly suppressive TME poses a significant challenge, causing heterogeneity of response or resistance in a considerable number of patients. This review focuses on the evasive attributes of the TME. Immune evasion mechanism in TME include immunosuppressive cells, cytokine and chemokine signaling, metabolic alterations and overexpression of immune checkpoint molecules such as PD-1, CTLA-4, LAG-3, TIM-3, TIGIT, BTLA and their interactions within the TME. In addition, this review focuses on the overcoming resistance by targeting immunosuppressive cells, normalizing tumor blood vessels, blocking two or three checkpoints simultaneously, combining vaccines, oncolytic viruses and metabolic inhibitors with ICIs or other therapies. This review also focuses on the necessity of finding predictive markers for the stratification of patients and to check response of ICIs treatment. It remains to be made certain by new research and intelligent innovations how these discoveries of the TME and its interplay facilitate ICI treatment and change the face of cancer treatment.

Engineered hybrid cell membrane nanovesicles for potentiated cancer immunotherapy through dual immune checkpoint inhibition

Immune checkpoint inhibitors (ICIs) have demonstrated remarkable success in treating various types of solid tumors; however, only a limited number of patients currently benefit from these therapeutic agents. Developing novel ICIs that elicit systemic and durable antitumor immune responses remains a significant challenge in improving immunotherapy outcomes. In this study, we engineered PD-1/LAG-3 receptors onto cell membrane nanovesicles to simultaneously block two immune checkpoints for the treatment of colorectal cancer. This dual-checkpoint blockade strategy led to significantly more potent tumor growth suppression in mice with MC38 xenografts compared to nanovesicles targeting PD-1 or LAG-3 alone. Notably, the hybrid nanovesicles substantially rejuvenated exhausted CD8+ T cells, promoting dendritic cell maturation and depleting regulatory T cells (Tregs). This research highlights the promising potential of cell membrane nanovesicles as an effective platform for delivering multiple immune checkpoints in cancer immunotherapy, offering a novel strategy to enhance therapeutic efficacy.

Sarcoid-like reactions in patients treated with checkpoint inhibitors for advanced solid tumors

IMPORTANCE

While new intrathoracic adenopathy in a patient with cancer can represent progression of disease, the differential diagnosis is broad. Sarcoid-like reactions (SLR) remain an underreported source of lymphadenopathy in patients treated with immune checkpoint inhibitors (ICI), with limited reports in patients with cancers other than melanoma.

OBJECTIVE

To characterize SLRs among patients treated with ICI for advanced solid tumors.

METHODS

Data were collected on the clinical, pathologic, and radiographic presentation of patients treated with ICI who developed clinical or imaging findings suggestive of an SLR, including the presence of hilar or mediastinal lymphadenopathy, cutaneous/subcutaneous involvement, and/or worsening of existing sarcoidosis on ICI.

RESULTS

Twelve patients were identified as having experienced an SLR. While 6 patients had melanoma, SLRs were also observed among patients with lung, gynecologic, and genitourinary cancers, including high-grade serous ovarian carcinoma, and an angiomyolipoma. Median time from initiation of ICI to diagnosis of an SLR was 3.4 months (range: 1.8-9.1). All but one patient (92%) were deemed to have had a radiographic response to ICI.

CONCLUSIONS AND RELEVANCE

Clinicians should maintain the awareness of the possibility of SLRs in patients receiving ICI, particularly in patients whose scans show evidence of "mixed" response, with decreases in certain lesions coupled with new/increasing intrathoracic lymphadenopathy and/or other systemic signs of sarcoid.

Role of Metastasectomy for Tissue Acquisition for Tumor-Infiltrating Lymphocyte Harvest and Biomarker/Genomic Testing

Tumor-infiltrating lymphocyte therapy is an emerging paradigm with promising early results for a patient population without many good alternatives. In some cases where the primary tumor or soft tissues metastases cannot be harvested, there may be a role for the thoracic surgeon to harvest tissue from pulmonary metastases. Typically, these can be limited resections with most cases being amenable to a wedge resection as only 1 cm of tissue is usually required. As a result, in appropriately selected patients, there has been shown to be a low risk of pulmonary, cardiovascular, infectious, and wound complications.

Neoadjuvant immunochemotherapy for locally advanced esophageal squamous cell carcinoma in real-world practice: an analysis of the clinical outcomes and long-term survival, and the feasibility of using major pathological response as a surrogate endpoint

BACKGROUND

Neoadjuvant immunochemotherapy is expected to become the standard treatment mode for locally advanced esophageal squamous cell carcinoma (ESCC). This study aims to analyze the clinical outcomes and long-term survival of neoadjuvant immunochemotherapy for locally advanced ESCC, and explore the feasibility of using major pathological response (MPR) as a surrogate endpoint.

METHODS

This real-world retrospective study consecutively included eligible patients with stage II-IVA locally advanced ESCC who received neoadjuvant immunochemotherapy and surgery between 2019 and 2022 at the Department of Thoracic Surgery, the First Affiliated Hospital, Zhejiang University School of Medicine.

RESULTS

This study collected a total of 166 patients, and ultimately included 126 patients after screening. The objective response rate (ORR) was 69.8% (88/126). The incidence of grade 3-4 adverse events (AEs) was 13.5% (17/126). MPR was observed in 49 (38.9%) patients, and 24 (19.0%) patients achieved a complete pathological response (pCR). The median progression-free survival (PFS) was 31.7 months and the 3-year PFS rate was 56.3%. The median overall survival (OS) was not reached and the 3-year OS rate was 70.6%. The median PFS of the non-MPR group was 25.0 months, with the MPR group not achieved (hazard ratio [HR], 2.503; 95% CI 1.359-4.610; P = 0.0022). The median OS in the non-MPR group was 31.7 months and not reached in the MPR group (HR, 3.607; 95% CI 1.576-8.254; P = 0.0012). MPR is an independent prognostic factor affecting OS (HR, 2.522; 95% CI 1.018-6.401; P = 0.046).

CONCLUSIONS

Neoadjuvant immunochemotherapy is safe and effective for locally advanced ESCC, and can result in certain survival benefits. MPR can serve as a surrogate endpoint for predicting long-term OS.

Five-year overall survival update from the HIMALAYA study of tremelimumab plus durvalumab in unresectable HCC

BACKGROUND & AIMS

In the phase III HIMALAYA study (NCT03298451), STRIDE (Single Tremelimumab Regular Interval Durvalumab) significantly improved overall survival (OS) versus sorafenib in unresectable HCC (uHCC) and demonstrated long-term survival benefits. We report an updated exploratory analysis of OS with 5 years of follow-up, including survival by multiple tumour response measures.

METHODS

Participants were randomised to STRIDE (tremelimumab plus durvalumab), durvalumab or sorafenib. OS, depth of response and serious adverse events (AEs) were assessed. Extended long-term survivors (eLTS; ≥48 months beyond randomisation) were described. Updated data cut-off: 01 March 2024.

RESULTS

Median (95% CI) follow-up durations were 62.49 (59.47-64.79) months (STRIDE) and 59.86 (58.32-61.54) months (sorafenib). The OS HR (95% CI) for STRIDE versus sorafenib was 0.76 (0.65-0.89). OS rates at 60 months for STRIDE versus sorafenib were 19.6% versus 9.4% overall, 28.7% versus 12.7% in participants achieving disease control per RECIST v1.1 and 50.7% versus 26.3% in participants achieving >25% tumour shrinkage. No late-onset treatment-related serious AEs were reported for STRIDE. There were more eLTS with STRIDE (83/393, 21.1%) than sorafenib (45/389, 11.6%), and extended long-term survival occurred across all clinically relevant subgroups.

CONCLUSIONS

At 5 years, STRIDE sustained an OS benefit versus sorafenib and maintained a manageable safety profile. OS benefit with STRIDE was improved in participants with disease control. Data suggest that any degree of tumour shrinkage with STRIDE can be associated with improved OS, indicating that conventional response measures may not fully capture STRIDE benefits. Nevertheless, participants experiencing deep responses appear to have the greatest benefit. STRIDE continues to set new benchmarks in uHCC with 1 in 5 patients alive at 5 years.

IMPACT AND IMPLICATIONS

The phase III HIMALAYA study showed that STRIDE (Single Tremelimumab Regular Interval Durvalumab) improved overall survival (OS) versus sorafenib in participants with unresectable HCC (uHCC), including after 4 years of follow-up. Understanding the efficacy and safety of STRIDE over the longer term is important for healthcare providers; here, we demonstrate that STRIDE sustained an OS benefit versus sorafenib and maintained a manageable safety profile after 5 years of follow-up. OS benefit with STRIDE was improved in participants with disease control and any degree of tumour shrinkage, indicating that conventional response measures may not fully capture the benefits of STRIDE. These findings are important as they set new benchmarks in uHCC and may help guide clinical decisions in the future.

Development of CD73 Inhibitors in Tumor Immunotherapy and Opportunities in Imaging and Combination Therapy

CD73 is a member of the membrane-bound enucleotidase family, which catalyzes the extracellular hydrolysis of adenosine monophosphate (AMP) to produce anti-inflammatory and immunosuppressive adenosine. As a novel checkpoint protein, CD73 is overexpressed in the immune system of various tumors, where adenosine is abundantly enriched. A large number of monoclonal antibodies (mAbs), nucleotides, and non-nucleotides as potent CD73 inhibitors are being discovered, providing opportunities for novel tumor immunotherapy. Currently, 18 CD73 inhibitors are in clinical trials, showing promising results in combination therapy for various solid tumors. The development of CD73-specific companion positron emission tomography imaging ligands holds potential for facilitating diagnosis, patient selection, and treatment efficacy evaluation throughout the entire process of CD73-targeted therapeutic development.

Artificial liver support systems bridge severe immune-mediated hepatotoxicity to clinical recovery

BACKGROUND

The incidence of hepatic immune-related adverse events has increased with the wide use of immune checkpoint inhibitors (ICIs), some immune-mediated hepatotoxicity (IMH) cases are severe and lack of clinical recommendations.

OBJECTIVE

This study aimed to evaluate the efficacy of artificial liver support systems (ALSSs) in the treatment of IMH.

METHODS

This retrospective case series included six patients with grade 4 hepatotoxicity with high bilirubin induced by ICIs treated between 1 January 2019 and 31 December 2021. All patients received ALSS treatment.

RESULTS

After treatment and recovery, four of the six patients experienced improvement in hepatotoxicity, with total bilirubin (TBIL) levels reduced to ≤ grade 2, and two patients achieved complete recovery (TBIL grade = 0).

CONCLUSION

ALSS serve as a therapeutic option for severe IMH.

Combining gut microbiota modulation and immunotherapy: A promising approach for treating microsatellite stable colorectal cancer

Colorectal cancer (CRC) is one of the most prevalent and lethal cancers worldwide, ranking third in incidence and second in mortality. While immunotherapy has shown promise in patients with deficient mismatch repair (dMMR) or high microsatellite instability (MSI-H), its effectiveness in proficient mismatch repair (pMMR) or microsatellite stable (MSS) CRC remains limited. Recent advances highlight the gut microbiota as a potential modulator of anti-tumor immunity. The gut microbiome can significantly influence the efficacy of immune checkpoint inhibitors (ICIs), especially in pMMR/MSS CRC, by modulating immune responses and systemic inflammation. This review explores the role of the gut microbiota in pMMR/MSS CRC, the mechanisms by which it may enhance immunotherapy, and current strategies for microbiota modulation. We discuss the potential benefits of combining microbiota-targeting interventions with immunotherapy to improve treatment outcomes for pMMR/MSS CRC patients.

Discovering biomarkers associated with infiltration of CD8+ T cells and tumor-associated fibrosis in colon adenocarcinoma using single-cell RNA sequencing and gene co-expression network

Background

Colorectal adenocarcinoma (COAD) is a prevalent malignant tumor associated with a high mortality rate. Within the tumor microenvironment, CD8+ T cells play a pivotal role in the anti-tumor immune response within the human body. Fibrosis directly and indirectly affects the therapeutic response of tumor immunotherapy. However, the significance of regulatory genes associated with tumor-associated fibrosis and CD8+ T cell infiltration remains uncertain. Therefore, it is imperative to identify biomarkers with prognostic value and elucidate the precise role of CD8+ T cells and tumor-associated fibrosis.

Methods

We performed a single-cell transcriptome analysis of COAD samples from the GEO database. To evaluate immune infiltration in COAD samples, we utilized CIBERSORT and ESTIMATE. Furthermore, we analyzed the correlation between CD8+ T cells and immune infiltration. To analyze COAD expression's quantitative immune cell composition data, we conducted a Weighted Gene Correlation Network Analysis and utilized a deconvolution algorithm. The data for these analyses were obtained from the GEO database. We utilized univariate Cox regression and LASSO analysis to create a prognostic model. The predictive model was assessed through Kaplan-Meier analysis, and a survival prediction nomogram was created. Additionally, we analyzed the correlation between the prognostic model and chemotherapy drug sensitivity. To estimate the expression of hub genes, we employed immunohistochemistry, real-time PCR, and western blot techniques.

Results

Single-cell transcriptome analysis has indicated a higher prevalence of CD8+ T cells in COAD tumor samples. The connection between COAD and CD8+ T cells was further confirmed by WGCNA and deconvolution analysis using the GEO database. The Protein-Protein Interaction network analysis revealed three hub genes: LARS2, SEZ6L2, and SOX7. A predictive model was subsequently created using LASSO and univariate COX regression, which included these three genes. Two of these hub genes (LARS2 and SEZ6L2) were found to be upregulated in COAD cell lines and tissues, while SOX7 was observed to be downregulated. The prognostic model demonstrated a significant association with CD8+ T cells, suggesting that these genes could serve as potential biomarkers and targets for gene therapy in treating COAD.

Conclusion

This study has identified three key genes associated with CD8+ T cells and the prognosis of COAD, providing new prognostic biomarkers for diagnosing and treating COAD.

Circulating Tumor DNA in High-Risk Stage II/III Cutaneous Melanoma: A Feasibility Study

BACKGROUND

Adjuvant therapies reduce recurrence in patients with clinical stage IIB/IIC/III melanoma; however, better risk stratification and patient selection are needed. Circulating tumor DNA (ctDNA) as a marker of micrometastatic residual disease is being explored for such purposes in other malignancies. We aimed to explore the feasibility of serial ctDNA monitoring in patients with stage II/III melanoma, as well as the association of ctDNA elevation with disease burden and outcomes.

METHODS

A single-institution prospective study was conducted on patients with clinical stage IIB/IIC/III melanoma. Primary tumor was sent to Natera for generation of a tumor-informed mPCR-NGS assay (Signatera™). Peripheral blood was collected for analysis at pre-specified timepoints. Patients were stratified by ctDNA elevations both pre- and postoperatively to compare tumor characteristics and recurrence-free survival (RFS).

RESULTS

Overall, 30 patients were enrolled. The median Breslow depth was 4.4 mm and 70% were ulcerated. Signatera™ assays were successfully created for all 30 patients. Median follow-up from the time of surgery was 16 months and 13 patients recurred with median RFS of 19 months. Eight of these 13 patients (62%) had detectable ctDNA levels predating their clinical or radiographic recurrence. Elevated ctDNA at the first post-operative timepoint was associated with worse RFS.

CONCLUSIONS

ctDNA monitoring is feasible for patients with high-risk cutaneous melanoma. Our findings suggest that detectable ctDNA post-operatively may be associated with worse outcomes. Elevations during surveillance may predict subsequent clinical recurrence; however, the role of ctDNA in adjuvant therapy decision-making and surveillance is not yet ready for broad application.

Research progress in bifunctional small molecules for cancer immunotherapy

Immunotherapy has become one of the most revolutionary modalities for cancer treatment with the approval of many anti-PD-L1 (programmed cell death-ligand 1)/PD-1 (programmed cell death-1) monoclonal antibodies (mAbs). However, anti-PD-L1/PD-1 mAbs suffer from several drawbacks including limited clinical efficacy (∼20 %), poor pharmacokinetics, and the development of immune resistance. Hence, the search for PD-1/PD-L1-based combination therapies and other PD-L1-based bifunctional small molecule modulators [e.g. PD-L1/HDAC (Histone Deacetylase), PD-L1/CXCL12 (C-X-C chemokine ligand 12), PD-L1/Tubulin, PD-L1/IDO1 (Indoleamine 2,3 dioxygenase 1), PD-L1/PARP (Poly(ADP-ribose) polymerase), PD-L1/STING (Stimulator of interferon genes), and PD-L1/NAMPT (Nicotinamide phosphoribosyltransferase)-targeting dual inhibitors] has been intensified with considerable strides achieved in the past couple of years. Herein, we summarize the latest development of bifunctional small molecules as immunotherapy for tumor treatment, including those PD-L1-based, A2AR (Adenosine 2A receptor)-based, IDO1-based, Toll-like receptor (TLR)-based, SHP2 (Src homology 2 domain-containing phosphatase 2)-based, and HPK1 (Hematopoietic progenitor kinase 1)-based dual-acting compounds. In addition, we also summarize the tumorigenesis and synergy mechanism of various targets. Finally, the challenges and future directions for bifunctional small molecules for cancer immunotherapy are also discussed in detail.

Multidimensional applications of prussian blue-based nanoparticles in cancer immunotherapy

Immunotherapy holds notable progress in the treatment of cancer. However, the clinical therapeutic effect remains a significant challenge due to immune-related side effects, poor immunogenicity, and immunosuppressive microenvironment. Nanoparticles have emerged as a revolutionary tool to surmount these obstacles and amplify the potency of immunotherapeutic agents. Prussian blue nanoparticles (PBNPs) exhibit multi-dimensional immune function in cancer immunotherapy, including acting as a nanocarrier to deliver immunotherapeutic agents, as a photothermal agent to improve the efficacy of immunotherapy through photothermal therapy, as a nanozyme to regulate tumor microenvironment, and as an iron donor to induce immune events related to ferroptosis and tumor-associated macrophages polarization. This review focuses on the advances and applications of PBNPs in cancer immunotherapy. First, the biomedical functions of PBNPs are introduced. Then, based on the immune function of PBNPs, we systematically reviewed the multidimensional application of PBNPs in cancer immunotherapy. Finally, the challenges and future developments of PBNPs-based cancer immunotherapy are highlighted.

Chromosome Missegregation Triggers Tumor Cell Pyroptosis and Enhances Anti-Tumor Immunotherapy in Colorectal Cancer

Immune checkpoint inhibitor (ICI) therapy is a promising anti-tumor therapeutic strategy; however, its efficacy in solid tumors is limited. Chromosome missegregation is common in various solid tumors; however, its role in tumor progression remains poorly understood, and its correlation with ICI is yet to be explored. Here, it is found that increased chromosome missegregation promotes tumor immune microenvironment, and eventually immunotherapeutic efficacy, by triggering pyroptosis. yin yang 2 (YY2) is identified as a mitotic checkpoint regulator, which promotes chromosome missegregation by upregulating BUB1B transcription. Increased chromosome missegregation promoted the formation of micronuclei and release of double-stranded DNA (dsDNA) into the cytosol, triggering an AIM2-mediated cytosolic dsDNA response. The subsequent pyroptosis strengthened the tumor immune microenvironment, thereby enhancing immunoinfiltration and cytotoxicity of CD8+ T cells, while preventing their exhaustion. Finally, through in vitro and in vivo experiments, it is demonstrated that combining YY2 overexpression-induced chromosome missegregation/cytosolic dsDNA response and PD-1 inhibitor significantly enhanced the efficacy of ICI immunotherapy in microsatellite instable and microsatellite stable colorectal cancer cells. Together, these findings provide new insights on the role of chromosome missegregation in triggering cytosolic dsDNA response-mediated pyroptosis and modulating the tumor immune microenvironment, suggesting a novel strategy for improving ICI therapeutic efficacy in colorectal cancer.

The clinical journey of belantamab mafodotin in relapsed or refractory multiple myeloma: lessons in drug development

Patients with relapsed/refractory multiple myeloma (RRMM) have a poor prognosis and a need remains for novel effective therapies. Belantamab mafodotin, an anti-B-cell maturation antigen antibody-drug conjugate, was granted accelerated/conditional approval for patients with RRMM who have received at least 4 prior lines of therapy, based on response rates observed in DREAMM-1/DREAMM-2. Despite the 41% response rate and durable responses observed with belantamab mafodotin in the Phase III confirmatory DREAMM-3 trial, the marketing license for belantamab mafodotin was later withdrawn from US and European markets when the trial did not meet its primary endpoint of superiority for progression-free survival compared with pomalidomide and dexamethasone. This review reflects on key lessons arising from the clinical journey of belantamab mafodotin in RRMM. It considers how incorporating longer follow-up in DREAMM-3 may have better captured the clinical benefits of belantamab mafodotin, particularly given its multimodal, immune-related mechanism of action with responses deepening over time. A non-inferiority hypothesis may have been more appropriate rather than superiority in the context of a monotherapy versus an active doublet therapy. Further, anticipation of, and planning for, non-proportional hazards arising from response heterogeneity may have mitigated loss of statistical power. With the aim of improving the efficacy of belantamab mafodotin, other Phase III trials in the RRMM development program (DREAMM-7 and DREAMM-8) proceeded to evaluate the synergistic potential of combination regimens in earlier lines of treatment. The aim was to increase the proportion of patients responding to belantamab mafodotin (and thus the likelihood of seeing a clear separation of the progression-free survival curve versus comparator regimens). Protocol amendments reflecting DREAMM-3 learnings could also be implemented prospectively on the combinations trials to optimize the follow-up duration and mitigate risk. The wider implications of the lessons learned for clinical research in RRMM and in earlier treatment settings are discussed.

Development of a prognostic model based on four genes related to exhausted CD8+ T cell in triple-negative breast cancer patients: a comprehensive analysis integrating scRNA-seq and bulk RNA-seq

Low immune infiltration is closely associated with poor clinical results and an unfavorable response to therapy in triple-negative breast cancer (TNBC). T-cell exhaustion (TEX) is a significant risk factor for tumor immunosuppression and invasion. Although improving TEX and enhancing effector function are promising strategies for strengthening immunotherapy, their role in the pathogenesis of TNBC remains unclear. This study's objective was to develop a prognostic model for TNBC based on exhausted CD8+ T-cell (CD8+ Tex)-related differentially expressed genes (DEGs) and to investigate its clinical and immune relevance. Initially, 398 CD8+ Tex-related genes were screened utilizing single-cell RNA sequencing (scRNA-seq) data from TNBC patients. Pseudotime analysis confirmed that CD8+ Tex mainly clustered at the end of the differentiation pathways, making them a critical subset in TNBC progression. By analyzing the TCGA cohort, ten CD8+ Tex-related DEGs were identified as significantly correlated with overall survival (OS) in TNBC patients, and a prognostic model containing four biomarkers (GBP1, CTSD, ABHD14B, and HLA-A) was constructed. The model demonstrated robust predictive capability in both the TCGA cohort and an external cohort, with the low-risk group exhibiting elevated expression of immunological checkpoint molecules and immune cell infiltration, as well as better responses to immunotherapy and chemotherapy. Furthermore, these four biomarkers were found to be highly expressed on CD8+ Tex and were associated with cellular communication efficiency. Therefore, this model is expected to be a new method for forecasting TNBC patients' prognosis and effectiveness of treatment, providing new insights for clinical decision-making.

Personalized Nanovaccine Based on STING-Activating Nanocarrier for Robust Cancer Immunotherapy

Tumor-specific T cells play a vital role in potent antitumor immunity. However, their efficacy is severely affected by the spatiotemporal orchestration of antigen-presentation as well as the innate immune response in dendritic cells (DCs). Herein, we develop a minimalist nanovaccine that exploits a dual immunofunctional polymeric nanoplatform (DIPNP) to encapsulate ovalbumin (OVA) via electrostatic interaction when the nanocarrier serves as both STING agonist and immune adjuvant in DCs. In vitro results reveal that the nanocarrier induces STING activation via facilitating interferon regulatory factor 3 phosphorylation by block poly 18-crown-6-yl methacrylate (P18C6MA) mediated K+ perturbation cascade with endoplasmic reticulum stress, and stimulates DC maturation via the Toll-like receptor 4 activation by primary amine. In vivo studies indicate that the smart nanovaccine dramatically inhibits tumor growth with a long-term immune memory response in both the B16-OVA and EG7-OVA tumor models. After combination with programmed death ligand-1 antibody (aPD-L1), mice survival rate is notably prolonged. In addition, DIPNP forms a personalized nanovaccine after resected autologous primary tumor cell membranes decoration with a high antitumor activity in a homologous distant tumor model. The rational design provides inspiration for personalized nanovaccine construction via immunofunctional nanocarriers.

Innovative CDR grafting and computational methods for PD-1 specific nanobody design

Introduction

The development of nanobodies targeting Programmed Cell Death Protein-1 (PD-1) offers a promising approach in cancer immunotherapy. This study aims to design and characterize a PD-1-specific nanobody using an integrated computational and experimental approach.

Methods

An in silico design strategy was employed, involving Complementarity-Determining Region (CDR) grafting to construct the nanobody sequence. The three-dimensional structure of the nanobody was predicted using AlphaFold2, and molecular docking simulations via ClusPro were conducted to evaluate binding interactions with PD-1. Physicochemical properties, including stability and solubility, were analyzed using web-based tools, while molecular dynamics (MD) simulations assessed stability under physiological conditions. The nanobody was produced and purified using Ni-NTA chromatography, and experimental validation was performed through Western blotting, ELISA, and dot blot analysis.

Results

Computational findings demonstrated favorable binding interactions, stability, and physicochemical properties of the nanobody. Experimental results confirmed the nanobody's specific binding affinity to PD-1, with ELISA and dot blot analyses providing evidence of robust interaction.

Discussion

This study highlights the potential of combining computational and experimental approaches for engineering nanobodies. The engineered PD-1 nanobody exhibits promising characteristics, making it a strong candidate for further testing in cancer immunotherapy applications.

Infiltrating T lymphocytes and tumor microenvironment within cholangiocarcinoma: immune heterogeneity, intercellular communication, immune checkpoints

Cholangiocarcinoma is the second most common primary liver cancer, and its global incidence has increased in recent years. Radical surgical resection and systemic chemotherapy have traditionally been the standard treatment options. However, the complexity of cholangiocarcinoma subtypes often presents a challenge for early diagnosis. Additionally, high recurrence rates following radical treatment and resistance to late-stage chemotherapy limit the benefits for patients. Immunotherapy has emerged as an effective strategy for treating various types of cancer, and has shown efficacy when combined with chemotherapy for cholangiocarcinoma. Current immunotherapies targeting cholangiocarcinoma have predominantly focused on T lymphocytes within the tumor microenvironment, and new immunotherapies have yielded unsatisfactory results in clinical trials. Therefore, it is essential to achieve a comprehensive understanding of the unique tumor microenvironment of cholangiocarcinoma and the pivotal role of T lymphocytes within it. In this review, we describe the heterogeneous immune landscape and intercellular communication in cholangiocarcinoma and summarize the specific distribution of T lymphocytes. Finally, we review potential immune checkpoints in cholangiocarcinoma.

Navigating the landscape of neoadjuvant immunotherapy for NSCLC: progress and controversies

Recently, attention has increasingly centered on non-small-cell lung cancer (NSCLC) with immune checkpoint inhibitors application. Numerous clinical studies have underscored the potential of immunotherapy in treating resectable NSCLC, highlighting its role in improving patient outcomes. However, despite these promising results, there is ongoing debate regarding the efficacy of immunological combination therapy strategies, the prevalence of treatment-related side effects, the identification of predictive biomarkers, and various other challenges within the neoadjuvant context. Careful consideration is essential to maximize the benefits of immunotherapy for patients with resectable NSCLC. This article offers a detailed overview of recent advancements in neoadjuvant immunotherapy for resectable NSCLC. By examining these developments, we aim to provide new perspectives and valuable insights into the benefits and challenges of applying neoadjuvant immunotherapy in clinical settings.

Network Medicine-Based Strategy Identifies Maprotiline as a Repurposable Drug by Inhibiting PD-L1 Expression via Targeting SPOP in Cancer

Immune checkpoint inhibitors (ICIs) are drugs that inhibit immune checkpoint (ICP) molecules to restore the antitumor activity of immune cells and eliminate tumor cells. Due to the limitations and certain side effects of current ICIs, such as programmed death protein-1, programmed cell death-ligand 1, and cytotoxic T lymphocyte-associated antigen 4 (CTLA4) antibodies, there is an urgent need to find new drugs with ICP inhibitory effects. In this study, a network-based computational framework called multi-network algorithm-driven drug repositioning targeting ICP (Mnet-DRI) is developed to accurately repurpose novel ICIs from ≈3000 Food and Drug Administration-approved or investigational drugs. By applying Mnet-DRI to PD-L1, maprotiline (MAP), an antidepressant drug is repurposed, as a potential PD-L1 modifier for colorectal and lung cancers. Experimental validation revealed that MAP reduced PD-L1 expression by targeting E3 ubiquitin ligase speckle-type zinc finger structural protein (SPOP), and the combination of MAP and anti-CTLA4 in vivo significantly enhanced the antitumor effect, providing a new alternative for the clinical treatment of colorectal and lung cancer.

Delayed Separation of Kaplan-Meier Curves is Commonly Observed in Studies of Advanced/Metastatic Solid Tumors Treated with Anti-PD-(L)1 Therapy: Systematic Review and Meta-Analysis

BACKGROUND

Immune checkpoint inhibitor (ICI) Kaplan-Meier (KM) curves often show delayed survival benefit followed by long-term survival in a subgroup of patients. Such outcomes can violate the proportional hazards assumption, leading to a loss of statistical power.

OBJECTIVE

We aimed to determine common trends in delayed separation to inform future ICI clinical trials.

PATIENTS AND METHODS

A literature search was performed using Trialtrove® to identify phase III trials of antiprogrammed cell death (ligand)-1 (anti-PD-[L]1) agents in locally advanced/metastatic solid tumors published between January 2010 and September 2021. The frequency of delayed separation of overall survival (OS) and progression-free survival (PFS) KM curves, correlation between duration of delayed separation in OS/PFS KM curves, and correlation between duration of delayed separation in OS/PFS KM curves with corresponding hazard ratios (HRs) were assessed in all-comer and PD-L1 enriched populations.

RESULTS

Eighty-five studies with OS/PFS KM curves were identified. Most studies showed delayed separation of OS (> 67.9%) and PFS (> 54.5%) KM curves. The correlation between the duration of delayed separation in OS/PFS KM curves was strongest in the PD-L1 enriched population (adjusted R2 = 0.66). No correlation was seen between the duration of delayed separation of OS KM curves and OS HR. A modest correlation was seen between the duration of delayed separation of PFS KM curves and PFS HR in all-comer and PD-L1 enriched populations (adjusted R2 = 0.24 and 0.31, respectively).

CONCLUSIONS

Delayed separation of KM curves was common in clinical trials of anti-PD-(L)1 agents. Understanding delayed separation is key to clinical study designs and assessing outcomes with ICIs.

Development and characterisation of [18F]TTDP, a novel T cell immunoglobulin and ITIM domain tracer, in humanised mice and non-human primates

PURPOSE

The T cell immunoglobulin and ITIM domain (TIGIT) blockade immunotherapy response is directly associated with individual differences of TIGIT expression on tumour-infiltrating lymphocytes (TILs) in tumour immune microenvironment (TIME) of non-small cell lung cancer (NSCLC). Here, we developed a TIGIT-targeted PET tracer to evaluate its feasibility in predicting immunotherapy efficacy, aiming to manage NSCLC patients accurately.

METHODS

We synthesised a 18F-labeled TIGIT-targeted D-peptide, [18F]TTDP, and investigated the specificity of [18F]TTDP both to murine TIGIT and human TIGIT by a series of in vitro and in vivo assays. [18F]TTDP PET imaging was performed in humanised immune system (HIS) mice models bearing NSCLC patient-derived xenografts (PDXs) to evaluate the predictive value of FDA-approved combination immunotherapy of atezolizumab plus tiragolumab. Lastly, rhesus macaque was applied for [18F] TTDP PET to explore the tracer's in vivo distribution and translational potential in non-human primates.

RESULTS

[18F]TTDP showed high specificity for both murine TIGIT and human TIGIT in vitro and in vivo. The HIS NSCLC PDX platform was successfully established for [18F]TTDP PET imaging, and tumour uptake of [18F]TTDP was significantly correlated with the TIGIT expression of TILs in the TIME. [18F]TTDP PET imaging, in predicting treatment response to the combination immunotherapy in NSCLC HIS-PDX models, showed a sensitivity of 83.33% and a specificity of 100%. In addition, [18F]TTDP PET also showed cross-species consistency of the tracer biodistribution between non-human primate and murine animals, and no adverse events were observed.

CONCLUSION

The combined implementation of the [18F]TTDP and HIS-PDX model creates a state-of-the-art preclinical platform that will impact the identification and validation of TIGIT-targeted PET image-guided diagnosis, treatment response prediction, beneficial patient screening, novel immunotherapies, and ultimately the outcome of NSCLC patients. We first provided in vivo biodistribution of [18F]TTDP PET imaging in rhesus macaque, indicating its excellent translational potential in the clinic.

A Turbo-Charging System-Like Contrast Agent for MRI-Guided STING Pathway-Activated Cancer Immunotherapy

To overcome the problems of Gd-based contrast agents (GBCAs) (nephrotoxicity and brain deposition) and stimulator of interferon genes (STING) agonists (poor stability, low delivery efficiency, and potential toxicity), in this study, a Turbo-charging system-like GBCA is designed and constructed for magnetic resonance imaging (MRI) guided STING pathway-activated cancer immunotherapy. Poly(acrylic acid) (PAA) is used to coordinate with Gd3+, forming a Gd/PAA macrochelate. Both Gd/PAA macrochelate and SR717 are conjugated to cystamine (CA) to obtain SR717-CA@Gd/PAA self-assembled nanoparticles (SAN), which are termed as Turbo S because of its similarity with the Turbo-charging system of cars. After accumulation in tumors and internalization in tumor cells, the disulfide linkage in Turbo S undergoes a cleavage process catalyzed by glutathione (GSH), leading to the release of Gd/PAA and SR717. The released Gd/PAA gain a high r1 value (17.11 mM-1 s-1 at 7.0 T; 57.81 mM-1 s-1 at 3.0 T), indicating its strong T1 imaging capability. Turbo S with a low dosage of SR717 (8.9 mg kg-1) achieved a higher tumor immunotherapeutic efficacy than free SR717 with a high dosage (30 mg kg-1). The excellent delivery efficiency, high tumor treatment efficacy, and superior biosafety demonstrate that the Turbo S can be used as a promising candidate for tumor immunotherapy.

Alleviating Tumor Hypoxia and Immunosuppression via Sononeoperfusion: A New Ally for potentiating anti-PD-L1 blockade of solid Tumor

The hypoxic and immunosuppressive tumor microenvironment (TME) remains a major obstacle to impede cancer immunotherapy. Here, we found that sononeoperfusion-a new effect of tumor perfusion enhancement induced by low mechanical index ultrasound stimulated microbubble cavitation (USMC)-ameliorated tumor tissue oxygenation and induced tumor vascular normalization (TVN). This TVN might be associated with the down-regulation of hypoxia-inducible factor 1-alpha (HIF-1α) and vascular endothelial growth factor (VEGF) within tumors. Moreover, the sononeoperfusion effect reduced the accumulation of immunosuppressive cells, such as regulatory T cells (Tregs), myeloid-derived suppressor cells (MDSCs) and M2-like tumor-associated macrophages (M2-TAMs), and decreased the production of immune inhibitory factors like transforming growth factor-β1 (TGF-β1), interleukin 10 (IL-10), chemoattractant chemokines CC-chemokine ligand 22 (CCL22), CCL28, adenosine and lactate within tumors. Notably, flow cytometry analysis revealed that sononeoperfusion not only increased the percentage of tumor infiltrating-CD8+ T cells, but also promoted the generation of interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) by these cells. Furthermore, the improved immune TME by sononeoperfusion effect sensitized anti-PD-L1 treatment both in MC38 colon cancer and Lewis lung carcinoma mice, resulting in tumor regression and prolonged survival. Mechanically, the enhanced efficacy of combination therapy was mainly based on promoting the infiltration and function of CD8+ T cells within tumors. Together, sononeoperfusion could ameliorate hypoxia and immunosuppression in the TME, thereby potentiating anti-PD-L1 therapy for solid tumors. This novel method of USMC generating sononeoperfusion effect may provide a new therapeutic modality for facilitating cancer immunotherapy.

Current trends in sensitizing immune checkpoint inhibitors for cancer treatment

Immune checkpoint inhibitors (ICIs) have dramatically transformed the treatment landscape for various malignancies, achieving notable clinical outcomes across a wide range of indications. Despite these advances, resistance to immune checkpoint blockade (ICB) remains a critical clinical challenge, characterized by variable response rates and non-durable benefits. However, growing research into the complex intrinsic and extrinsic characteristics of tumors has advanced our understanding of the mechanisms behind ICI resistance, potentially improving treatment outcomes. Additionally, robust predictive biomarkers are crucial for optimizing patient selection and maximizing the efficacy of ICBs. Recent studies have emphasized that multiple rational combination strategies can overcome immune checkpoint resistance and enhance susceptibility to ICIs. These findings not only deepen our understanding of tumor biology but also reveal the unique mechanisms of action of sensitizing agents, extending clinical benefits in cancer immunotherapy. In this review, we will explore the underlying biology of ICIs, discuss the significance of the tumor immune microenvironment (TIME) and clinical predictive biomarkers, analyze the current mechanisms of resistance, and outline alternative combination strategies to enhance the effectiveness of ICIs, including personalized strategies for sensitizing tumors to ICIs.

A comprehensive review of immune checkpoint inhibitors for cancer treatment

Immunology-based therapies are emerging as an effective cancer treatment, using the body's immune system to target tumors. Immune checkpoints, which regulate immune responses to prevent tissue damage and autoimmunity, are often exploited by cancer cells to avoid destruction. The discovery of checkpoint proteins like PD-1/PD-L1 and CTLA-4 was pivotal in developing cancer immunotherapy. Immune checkpoint inhibitors (ICIs) have shown great success, with FDA-approved drugs like PD-1 inhibitors (Nivolumab, Pembrolizumab, Cemiplimab), PD-L1 inhibitors (Atezolizumab, Durvalumab, Avelumab), and CTLA-4 inhibitors (Ipilimumab, Tremelimumab), alongside LAG-3 inhibitor Relatlimab. Research continues on new checkpoints like TIM-3, VISTA, B7-H3, BTLA, and TIGIT. Biomarkers like PDL-1 expression, tumor mutation burden, interferon-γ presence, microbiome composition, and extracellular matrix characteristics play a crucial role in predicting responses to immunotherapy with checkpoint inhibitors. Despite their effectiveness, not all patients experience the same level of benefit, and organ-specific immune-related adverse events (irAEs) such as rash or itching, colitis, diarrhea, hyperthyroidism, and hypothyroidism may occur. Given the rapid advancements in this field and the variability in patient outcomes, there is an urgent need for a comprehensive review that consolidates the latest findings on immune checkpoint inhibitors, covering their clinical status, biomarkers, resistance mechanisms, strategies to overcome resistance, and associated adverse effects. This review aims to fill this gap by providing an analysis of the current clinical status of ICIs, emerging biomarkers, mechanisms of resistance, strategies to enhance therapeutic efficacy, and assessment of adverse effects. This review is crucial to furthering our understanding of ICIs and optimizing their application in cancer therapy.

Radiomic and dosimetric parameter-based nomogram predicts radiation esophagitis in patients with non-small cell lung cancer undergoing combined immunotherapy and radiotherapy

Background

The combination of immune checkpoint inhibitors (ICIs) and radiotherapy (RT) may increase the risk of radiation esophagitis (RE). This study aimed to establish and validate a new nomogram to predict RE in patients with non-small cell lung cancer (NSCLC) undergoing immunochemotherapy followed by RT (ICI-RT).

Methods

The 102 eligible patients with NSCLC treated with ICI-RT were divided into training (n = 71) and validation (n = 31) cohorts. Clinicopathologic features, dosimetric parameters, inflammatory markers, and radiomic score (Rad-score) were included in the univariate logistic regression analysis, and factors with p < 0.05 in the univariate analysis were included in the multivariate logistic regression analysis. Factors with significant predictive values were obtained and used for developing the nomogram. The area under the receiver operating characteristic curve (AUC), calibration curve, and decision curve were used to validate the model.

Results

A total of 38 (37.3%) patients developed RE. Univariate and multivariate analyses identified the following independent predictors of RE: a maximum dose delivered to the esophagus >58.4 Gy, a mean esophagus dose >13.3 Gy, and the Rad-score. The AUCs of the nomogram in the training and validation cohorts were 0.918 (95% confidence interval [CI]: 0.824-1.000) and 0.833 (95% CI: 0.697-0.969), respectively, indicating good discrimination. The calibration curves showed good agreement between the predicted occurrence of RE and the actual observations. The decision curve showed a satisfactory positive net benefit at most threshold probabilities, suggesting a good clinical effect.

Conclusions

We developed and validated a nomogram based on imaging histological features and RT dosimetric parameters. This model can effectively predict the occurrence of RE in patients with NSCLC treated using ICI-RT.

Artificial intelligence for chimeric antigen receptor-based therapies: a comprehensive review of current applications and future perspectives

Using artificial intelligence (AI) to enhance chimeric antigen receptor (CAR)-based therapies' design, production, and delivery is a novel and promising approach. This review provides an overview of the current applications and challenges of AI for CAR-based therapies and suggests some directions for future research and development. This paper examines some of the recent advances of AI for CAR-based therapies, for example, using deep learning (DL) to design CARs that target multiple antigens and avoid antigen escape; using natural language processing to extract relevant information from clinical reports and literature; using computer vision to analyze the morphology and phenotype of CAR cells; using reinforcement learning to optimize the dose and schedule of CAR infusion; and using AI to predict the efficacy and toxicity of CAR-based therapies. These applications demonstrate the potential of AI to improve the quality and efficiency of CAR-based therapies and to provide personalized and precise treatments for cancer patients. However, there are also some challenges and limitations of using AI for CAR-based therapies, for example, the lack of high-quality and standardized data; the need for validation and verification of AI models; the risk of bias and error in AI outputs; the ethical, legal, and social issues of using AI for health care; and the possible impact of AI on the human role and responsibility in cancer immunotherapy. It is important to establish a multidisciplinary collaboration among researchers, clinicians, regulators, and patients to address these challenges and to ensure the safe and responsible use of AI for CAR-based therapies.

Mapping the Binding Hotspots and Transient Binding Pockets on V-Domain Immunoglobulin Suppressor of T Cell Activation Protein Surface

V-domain immunoglobulin suppressor of T cell activation (VISTA), an inhibitory immune checkpoint present on both immune and tumor cells, has emerged as a highly promising target for cancer therapy due to its potential to overcome resistance encountered with existing immune checkpoint treatments. VSIG-3 is determined as an inhibitory ligand for VISTA, leading to the suppression of T cell proliferation. However, hotspots between VISTA/VSIG-3 protein-protein interaction remain ambiguous, mainly attributed to the lack of the structure of the VISTA/VSIG-3 complex. Therefore, in this study, in order to determine the energetic contributions of the interfacial residues on VISTA, we first constructed VISTA/VSIG-3 complex models by the protein docking method, followed by molecular dynamics simulations, binding free-energy decomposition, and alanine scanning. Results suggested that the putative hotspots in VISTA comprise residues His32, Tyr37, Thr35, Glu47, Val48, Gln49, Glu53, Arg54, Gln73, His122, and His126. Moreover, the distribution of the hotspots was clustered into two regions (hot regions I and II), and by using the TRAPP tool, transient subpockets within the hot regions were identified. Furthermore, conformational states of the binding pockets exhibiting druggability scores higher than those observed in the crystal structure were found. Overall, we hope that the findings outlined in this study can be used to facilitate the development of inhibitors targeting the VISTA/VSIG-3 immune checkpoint pathway in the future.

Platinum-Metformin Conjugates Acting as Promising PD-L1 Inhibitors through the AMP-Activated Protein Kinase Mediated Lysosomal Degradation Pathway

With the development of metalloimmunology, the potential of platinum drugs in cancer immunotherapy has attracted extensive attention. Although immunochemotherapy combining PD-1/PD-L1 antibodies with platinum drugs has achieved great success in the clinic, combination therapy commonly brings new problems. Herein, we have developed a platinum-metformin conjugate as a promising alternative to antibody-based PD-L1 inhibitors, not only disrupting PD-1/PD-L1 axis on cell surface but also down-regulating the total PD-L1 levels in non-small cell lung cancer (NSCLC) cells comprehensively, thus achieving highly efficient immunochemotherapy by a single small molecule. Mechanism studies demonstrate that Pt-metformin conjugate can selectively accumulate in lysosomes, promote lysosomal-dependent PD-L1 degradation via the AMPK-TFEB pathway, and modulate the upstream regulatory proteins related to PD-L1 expression (e.g. HIF-1α and NF-κB), eventually decreasing the total abundance of PD-L1 in NSCLC, overcoming tumor hypoxia, and activating anti-tumor immunity in vivo. This work suggests an AMPK-mediated lysosomal degradation pathway of PD-L1 for the first time and provides a unique design perspective for the development of novel platinum drugs for immunochemotherapy.

Metal-based smart nanosystems in cancer immunotherapy

Metals are an emerging topic in cancer immunotherapy that have shown great potential in modulating cancer immunity cycle and promoting antitumor immunity by activating the intrinsic immunostimulatory mechanisms which have been identified in recent years. The main challenge of metal-assisted immunotherapy lies in the fact that the free metals as ion forms are easily cleared during circulation, and even cause systemic metal toxicity due to the off-target effects. With the rapid development of nanomedicine, metal-based smart nanosystems (MSNs) with unique controllable structure become one of the most promising delivery carriers to solve the issue, owing to their various endogenous/external stimuli-responsiveness to release free metal ions for metalloimmunotherapy. In this review, the state-of-the-art research progress in metal-related immunotherapy is comprehensively summarized. First, the mainstream mechanisms of MSNs-assisted immunotherapy will be delineated. The immunological effects of certain metals and categorization of MSNs with different characters and compositions are then provided, followed by the representative exemplar applications of MSNs in cancer treatment, and synergistic combination immunotherapy. Finally, we conclude this review with a summary of the remaining challenges associated with MSNs and provide the authors' perspective on their further advances.

Nemvaleukin alfa, a modified interleukin-2 cytokine, as monotherapy and with pembrolizumab in patients with advanced solid tumors (ARTISTRY-1)

BACKGROUND

Nemvaleukin alfa (nemvaleukin, ALKS 4230) is a novel, engineered cytokine that selectively binds to the intermediate-affinity interleukin-2 receptor, preferentially activating CD8+ T cells and natural killer cells, with minimal expansion of regulatory T cells, thereby mitigating the risk of toxicities associated with high-affinity interleukin-2 receptor activation. Clinical outcomes with nemvaleukin are unknown. ARTISTRY-1 investigated the safety, recommended phase 2 dose (RP2D), and antitumor activity of nemvaleukin in patients with advanced solid tumors.

METHODS

This was a three-part, open-label, phase 1/2 study: part A, dose-escalation monotherapy, part B, dose-expansion monotherapy, and part C, combination therapy with pembrolizumab. The study was conducted at 32 sites in 7 countries. Adult patients with advanced solid tumors were enrolled and received intravenous nemvaleukin once daily on days 1-5 (21-day cycle) at 0.1-10 µg/kg/day (part A), or at the RP2D (part B), or with pembrolizumab (part C). Primary endpoints were RP2D selection and dose-limiting toxicities (part A), and overall response rate (ORR) and safety (parts B and C).

RESULTS

From July 2016 to March 2023, 243 patients were enrolled and treated (46, 74, and 166 in parts A, B, and C, respectively). The maximum tolerated dose was not reached. RP2D was determined as 6 µg/kg/day. ORR with nemvaleukin monotherapy was 10% (7/68; 95% CI 4 to 20), with seven partial responses (melanoma, n=4; renal cell carcinoma, n=3). Robust CD8+ T and natural killer cell expansion, and minimal regulatory T cell expansion were observed following nemvaleukin treatment. ORR with nemvaleukin plus pembrolizumab was 13% (19/144; 95% CI 8 to 20), with 5 complete and 14 partial responses; 6 responses were in PD-(L)1 inhibitor-approved and five in PD-(L)1 inhibitor-unapproved tumor types. Three responses were in patients with platinum-resistant ovarian cancer. The most common grade 3-4 treatment-related adverse events (TRAEs) in parts B and C, respectively, were neutropenia (49%, 21%) and anemia (10%, 11%); 4% of patients in each part discontinued due to TRAEs.

CONCLUSIONS

Nemvaleukin was well tolerated and demonstrated promising antitumor activity across heavily pretreated advanced solid tumors. Phase 2/3 studies of nemvaleukin are ongoing.

TRIAL REGISTRATION NUMBER

NCT02799095.

Concurrent immune checkpoint blockade for enhanced cancer immunotherapy utilizing engineered hybrid nanovesicles

Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment, demonstrating unprecedented efficacy against advanced cancers. However, their clinical applications are significantly hampered by low overall response rates. Dual blockade of two immune checkpoints represents a promising strategy to enhance immunotherapeutic efficacy. In this study, we developed hybrid cell membrane nanovesicles adorned with PD-1 and SIRPα receptors for combination immunotherapy in melanoma. Our hybrid nanovesicles (PD-1/SIRPα NVs) demonstrated high specificity to PD-L1 and CD47 ligands, facilitating the phagocytosis of melanoma cells by macrophages. In a melanoma mouse model, PD-1/SIRPα NVs significantly suppressed 77% of tumor growth and elicited a robust antitumor immune response for immunotherapy. In conclusion, our findings highlight the promising potential of PD-1/SIRPα NVs as novel and effective ICIs for cancer immunotherapy.

Regulatory T cells in immune checkpoint blockade antitumor therapy

Regulatory T cells (Tregs), an essential component of the human immune system, are a heterogeneous group of T lymphocytes with the ability to suppress immune responses and maintain immune homeostasis. Recent evidence indicates that Tregs may impair antitumor immunity and facilitate cancer progression by weakening functions of effector T cells (Teffs). Consequently, targeting Tregs to eliminate them from tumor microenvironments to improve Teffs' activity could emerge as an effective strategy for cancer immunotherapy. This review outlines the biology of Tregs, detailing their origins, classification, and crucial markers. Our focus lies on the complex role of Tregs in cancer's development, progression and treatment, particularly on their suppressive role upon antitumor responses via multiple mechanisms. We delve into Tregs' involvement in immune checkpoint blockade (ICB) therapy, their dual effect on cancer immunotherapy and their potential biomarkers for ICB therapy effectiveness. We also summarize advances in the therapies that adjust Tregs to optimize ICB therapy, which may be crucial for devising innovative cancer treatment strategies.

Determining doses for backfill cohorts based on patient-reported outcome

BACKGROUND

Incorporating backfill cohorts in phase I oncology trials is a recently developed strategy for dose optimization. However, the efficacy assessment window is long in general, causing a lag in identifying ineffective doses and more patients being backfilled to those doses. There is necessity to investigate how to use patient-reported outcomes (PRO) to determine doses for backfill cohorts.

METHODS

We propose a unified Bayesian design framework, called 'Backfill-QoL', to utilize patient-reported quality of life (QoL) data into phase I oncology trials with backfill cohorts, including methods for trial monitoring, algorithm for dose-finding, and criteria for dose selection. Simulation studies and sensitivity analyses are conducted to evaluate the proposed Backfill-QoL design.

RESULTS

The simulation studies demonstrate that the Backfill-QoL design is more efficient than traditional dose-expansion strategy, and fewer patients would be allocated to doses with unacceptable QoL profiles. A user-friendly Windows desktop application is developed and freely available for implementing the proposed design.

CONCLUSIONS

The Backfill-QoL design enables continuous monitoring of safety, efficacy and QoL outcomes, and the recommended phase II dose (RP2D) can be identified in a more patient-centered perspective.

Genomic and transcriptomic landscape of human gastrointestinal stromal tumors

Gastrointestinal stromal tumor (GISTs) are clinically heterogenous exhibiting varying degrees of disease aggressiveness in individual patients. We comprehensively describe the genomic and transcriptomic landscape of a cohort of 117 GISTs including 31 low-risk, 18 intermediate-risk, 29 high-risk, 34 metastatic and 5 neoadjuvant GISTs from 105 patients. GISTs have notably low tumor mutation burden but widespread copy number variations. Aggressive GISTs harbor remarkably more genomic aberrations than low-/intermediate-risk GISTs. Complex genomic alterations, chromothripsis and kataegis, occur selectively in aggressive GISTs. Despite the paucity of mutations, recurrent inactivating YLPM1 mutations are identified (10.3%, 7 of 68 patients), enriched in high-risk/metastatic GIST and functional study further demonstrates YLPM1 inactivation promotes GIST proliferation, growth and oxidative phosphorylation. Spatially and temporally separated GISTs from individual patients demonstrate complex tumor heterogeneity in metastatic GISTs. Finally, four prominent subtypes are proposed with different genomic features, expression profiles, immune characteristics, clinical characteristics and subtype-specific treatment strategies. This large-scale analysis depicts the landscape and provides further insights into GIST pathogenesis and precise treatment.

CD8+ T-cell exhaustion: Impediment to triple-negative breast cancer (TNBC) immunotherapy

CD8+ T-cell exhaustion has been identified as a significant contributor to immunosuppression and immune escape in triple-negative breast cancer (TNBC). Dysfunction due to cell exhaustion is characterized by reduced effector capacity and sustained expression of inhibitory receptors (IRs). The factors contributing to CD8+ T-cell exhaustion are multifaceted, encompassing external influences such as the upregulation of IRs, reduction of effector cytokines, and internal changes within the immune cell, including transcriptomic alterations, epigenetic landscape remodeling, and metabolomic shifts. The impact of the altered TNBC tumor microenvironment (TME) on Tex is also a critical consideration. The production of exhausted CD8+ T-cells (CD8+ Tex) is positively correlated with poor prognosis and reduced response rates to immunotherapy in TNBC patients, underscoring the urgent need for the development of novel TNBC immunotherapeutic strategies that target the mechanisms of CD8+ T-cell exhaustion. This review delineates the dynamic trajectory of CD8+ T-cell exhaustion development in TNBC, provides an update on the latest research advancements in understanding its pathogenesis, and offers insights into potential immunotherapeutic strategies.

Biodegradable nanoparticles-mediated targeted drug delivery achieves trans-spatial immunotherapy

Immunotherapy has been seriously retarded due to inadequate antigen presentation and a tumor cell-dominated immunosuppressive microenvironment (TME). Herein, biodegradable multifunctional mesoporous silica nanoparticles, with dispersed carbon nanodots incorporated into the frameworks, active TKD peptide modification on the surfaces and hydrophobic drug loading in the pores, were prepared for targeted chemotherapy synergized with trans-spatial immunotherapy. The nanoparticles were biodegradable due to nanodot-induced framework swelling, which would (1) kill the in situ tumor cells and promote antigen release by targeted chemotherapy and (2) trigger biodegraded debris involving TKD and CDs to largely adsorb the tumor antigens via π-π conjugation synergized hydrophobic interactions and then massively transport these antigens from the tumor cell-dominated TME to the immune cell-dominated spleen via TKD-mediated small size effects. Thereafter, these antigens can be processed into antigen peptides via TKD-mediated lysosome endocytosis and then activate T cells in the spleen via MHC complex construction and dendritic cell cytomembrane presentation. Therefore, improved immunotherapy with trans-spatial antigen presentation avoided TME immunosuppression, which when synergized with targeted chemotherapy, markedly enhanced the therapeutic outcomes of triple-negative breast cancer.

RIG-I is an intracellular checkpoint that limits CD8+ T-cell antitumour immunity

Retinoic acid-inducible gene I (RIG-I) is a pattern recognition receptor involved in innate immunity, but its role in adaptive immunity, specifically in the context of CD8+ T-cell antitumour immunity, remains unclear. Here, we demonstrate that RIG-I is upregulated in tumour-infiltrating CD8+ T cells, where it functions as an intracellular checkpoint to negatively regulate CD8+ T-cell function and limit antitumour immunity. Mechanistically, the upregulation of RIG-I in CD8+ T cells is induced by activated T cells, and directly inhibits the AKT/glycolysis signalling pathway. In addition, knocking out RIG-I enhances the efficacy of adoptively transferred T cells against solid tumours, and inhibiting RIG-I enhances the response to PD-1 blockade. Overall, our study identifies RIG-I as an intracellular checkpoint and a potential target for alleviating inhibitory constraints on T cells in cancer immunotherapy, either alone or in combination with an immune checkpoint inhibitor.

Small molecules from antibody pharmacophores (SMAbPs) as a hit identification workflow for immune checkpoints

Small-molecule modulators of immune checkpoints are poised to revolutionize cancer immunotherapy. However, efficient strategies for hit identification are lacking. We introduce small molecules from antibody pharmacophores (SMAbPs), a workflow leveraging cocrystal structures of checkpoints with antibodies to create pharmacophore maps for virtual screening. Applying SMAbPs to five immune checkpoints yielded hits with submicromolar potency in both cell-free and cellular assays. Notably, SMAbPs identified the most potent T cell immunoglobulin and mucin-domain containing-3 and V-domain immunoglobulin suppressor of T cell activation (VISTA) inhibitors reported to date and first-in-class modulators of B and T lymphocyte attenuator, 4-IBB, and CD27. Targeting inhibitory and costimulatory checkpoints with hits identified through SMAbPs demonstrated remarkable in vivo antitumor activity, exemplified by MG-V-53 (VISTA inhibitor) and MG-C-30 (CD27 agonist), which significantly reduced tumor volumes in MC38 and EG7-OVA mouse models, respectively.

Methylation and transcriptome analyses construct a prognostic model and reveal the suppressor role of VMO1 in lung adenocarcinoma

BACKGROUND

DNA methylation is an important epigenetic mechanism of gene regulation. The aberrant DNA methylation has been found to play an important role in the initiation and progression of tumors.

RESULTS

Transcriptome and DNA methylation data of lung adenocarcinoma (LUAD) patients were co-analyzed and 95 methylation-driven genes (MDGs) was found in relation to LUAD. A prognostic model based on 3 MDGs (GMNN, SPINK2 and VMO1) was constructed by Univariate and Multivariate cox regression analyses. The risk score generated from the prognostic model could be used to classify LUAD patients into high and low risk groups. Furthermore, it was found that the risk score was associated with tumor microenvironment (TME) and clinical characteristics (survival status and T stage) of patients. Interestingly, we identified and validated that the patients in the low-risk group responded better to immunotherapy treatment. Then, a nomogram model based on the risk score and clinical characteristics was established which showed significant prediction value. The down-regulation and hypermethylation levels of vitelline membrane outer layer protein 1 homolog (VMO1) were verified in paired LUAD tumor and non-tumor tissues by pyrosequencing assay and RT-qPCR. Furthermore, MTT, migration and wound healing assays were performed with lentivector-mediated ectopic over-expression and 5-Aza-dC demethylation followed by siRNA rescue experiments to investigate the role of VMO1 in LUAD cells. Our results indicated that VMO1 could inhibit proliferation and migration of A549 and NCI-H1299 cells.

CONCLUSIONS

In summary, our experiments constructed a prognostic model with high capacity for risk prediction in LUAD patients. VMO1 had a malignant suppressor role in LUAD cells. The correlation between risk score and TME might elucidate a potential mechanism of oncogenesis and provide an avenue for further therapeutic targets.

Delivery approaches of immunomodulatory nucleic acids for cancer therapy

Messenger RNA (mRNA) vaccines have made remarkable public health contributions during the pandemic and initiated a new era for nucleic acid-based therapeutics. With the unique strength of nucleic acids, including not only mRNA but also DNA, microRNA, small interfering RNA (siRNA), and other nucleic acids, either in tuning off genes or introducing function, nucleic acid therapeutics have been regarded as potential candidates for the treatment of many different diseases, especially for the immunomodulation in cancer. However, the scope of the applications was limited by the challenges in delivery due to intrinsic properties of nucleic acids including low stability, immunogenicity, and toxicity. Bioengineering approaches toward efficient and targeted delivery of therapeutic nucleic acids have gained momentum in clinical applications in the past few decades. Recent advances in the biotechnological approaches for the delivery of mRNA, siRNA, and clustered regularly interspaced short palindromic repeats (CRISPR)/Cas for immunomodulatory are promising alternatives in designing future cancer immunotherapy.