Journal for Immunotherapy of Cancer最新文献

The recent study by Di Federico et al provides valuable insights into the intrapatient heterogeneity of programmed death-ligand 1 (PD-L1) expression and tumor mutational burden (TMB) in non-small cell lung cancer (NSCLC), and its potential impact on responses to immune checkpoint inhibitors. This commentary examines several biological factors that may contribute to such variability, including cytokine signaling, metabolic changes within the tumor microenvironment, and intrinsic tumor heterogeneity. We also consider possible interactions between PD-L1 and TMB in the context of immune evasion. Furthermore, we highlight the need for more rigorous patient stratification in future studies and suggest that dynamic monitoring tools like liquid biopsy could enhance clinical decision-making. A deeper understanding of biomarker variability mechanisms may ultimately support more precise and effective personalized immunotherapy strategies for NSCLC.

Background: Cysteine-cysteine chemokine receptors 2 (CCR2) and 5 (CCR5) contribute to immune suppression in tumor microenvironments. CCR2 and CCR5 antagonists have demonstrated antitumor activity in pancreatic ductal adenocarcinoma (PDAC) and colorectal cancer (CRC), respectively. This phase 1b/2, open-label study evaluated BMS-813160, a CCR2/5 dual antagonist, in combination with chemotherapy±nivolumab in advanced PDAC or metastatic CRC.

Methods: Part 1 included patients with metastatic untreated (first-line (1L)) PDAC, 1L CRC, or previously treated (second or third line (2/3L)) microsatellite stable (MSS) CRC. Patients received 2 weeks of BMS-813160 monotherapy (300 mg two times a day, 600 mg once daily, 300 mg once daily, or 150 mg once daily) and then BMS-813160+chemotherapy (gemcitabine+nab-paclitaxel (gem/nabP; 1L PDAC), 5-fluorouracil+leucovorin+irinotecan (FOLFIRI; 1L CRC)), or nivolumab (2/3L MSS CRC).Part 2 included patients with metastatic 1L PDAC or 2L CRC. Patients received BMS-813160 300 mg two times a day+gem/nabP±nivolumab (1L PDAC), BMS-813160 300 mg two times a day or 150 mg once daily+FOLFIRI (2L CRC), or chemotherapy alone. Primary endpoints were safety and pharmacodynamics (Part 1) and efficacy (Part 2).

Results: In Part 1, 22 of 75 (29%) and 54 of 72 (72%) patients experienced a treatment-related adverse event during monotherapy lead-in and overall, respectively. Two dose-limiting toxicities (rash and pericardial effusion with pericarditis, both grade 3) occurred. In Part 2, patients with 1L PDAC who received BMS-813160 300 mg two times a day+gem/nabP+nivolumab achieved an overall response rate (ORR) of 37% (13/35); the median duration of response (DOR) was 45 weeks (95% CI 26.1 to not evaluable). ORRs with BMS-813160 300 mg two times a day+gem/nabP and gem/nabP alone were 26% (9/35) and 28% (9/32), respectively; median DORs were 121 and 31 weeks, respectively. Progression-free survival rates at 24 weeks were 56% (BMS-813160 300 mg two times a day+gem/nabP+nivolumab), 56% (BMS-813160 300 mg two times a day+gem/nabP), and 50% (gem/nabP). ORRs in 2L CRC were 19% (6/32; BMS-813160 300 mg two times a day+FOLFIRI), 13% (4/32; BMS-813160 150 mg once daily+FOLFIRI), and 27% (7/26; FOLFIRI).

Conclusions: In 1L PDAC, BMS-813160 300 two times a day+gem/nabP±nivolumab demonstrated durable antitumor response and was well tolerated. BMS-813160 combination regimens were tolerable in other cohorts, but clinical efficacy was not demonstrated.

Trial registration number: NCT03184870.

Background: Pancreatic ductal adenocarcinoma (PDAC) remains largely refractory to chimeric antigen receptor (CAR)-T cell therapy. Insufficient T cell infiltration, a highly immunosuppressive microenvironment, and antigen loss pose major challenges for CAR-T cell therapy.

Methods: We investigated therapeutic synergies of synthetic 5'-triphosphate RNA (3p-RNA), an agonist of the cytoplasmic double-stranded RNA sensor Retinoic Acid Inducible Gene I (RIG-I), and CAR-T cell therapy using syngeneic and human xenograft PDAC models. Tumor growth, chemokine secretion, immune-cell composition, CAR-T persistence, and endogenous T cell responses were assessed by flow cytometry, multiplex cytokine arrays, Enzyme-linked Immunospot (ELISpot), and vaccination-challenge.

Results: 3p-RNA provoked rapid type I interferon accompanied with chemokine ligand CCL5 and CXCL9/10/11 secretion, creating chemokine gradients that recruited chemokine receptor CCR5⁺/CXCR3⁺ CAR-T cells into tumors. RIG-I activation enhanced CAR-T cell proliferation, activity, and CAR-T persistence. Combination therapy eradicated established tumors in 60%-70% of mice, whereas either monotherapy was largely ineffective. Cured animals rejected CAR antigen-negative tumor cell rechallenge, demonstrating antigen-spreading and endogenous T cell responses.

Conclusions: Intratumoral RIG-I priming reprograms the PDAC microenvironment, transforming a non-responsive cancer into a CAR-T-permissive one, supporting durable, poly-antigenic immunity. These findings position 3p-RNA as a rapid, clinically tractable co-therapy to extend CAR-T efficacy to solid tumors.

Background: Canine oral malignant melanoma (OMM) is a highly aggressive tumor, with several available treatment options, though few achieve durable response or complete remission. Because of its biological similarity to human mucosal melanoma, canine OMM represents a valuable spontaneous model for translational immunotherapy studies. Anti-programmed cell death protein 1 (PD-1) antibody therapy has shown promise in canine OMM; however, predictive biomarkers for treatment response and survival have not been identified.

Methods: We conducted a multicenter, prospective, investigator-initiated clinical trial to evaluate the safety and efficacy of a caninized anti-canine PD-1 monoclonal antibody (ca-4F12-E6) in 150 dogs with advanced OMM. The dogs were administered 3 mg/kg ca-4F12-E6 intravenously every 2 weeks. Treatment response was assessed using cRECIST V.1.0. Biomarker analyses included peripheral blood parameters, cytokine/chemokines, peripheral lymphocyte subsets, microsatellite instability (MSI), immunohistochemistry for immune cell and mismatch repair protein markers, and RNA sequencing of the tumor tissue. Associations with clinical outcomes were determined by logistic regression and Cox proportional hazards models.

Results: The overall response rate was 14.7%, with a best overall response rate of 16.7%. Treatment-related adverse events occurred in 40.0% of the dogs, which were primarily grade 1-3. Increased baseline white blood cell, neutrophil count, and C reactive protein levels were significantly associated with poor response, shorter progression-free survival, and reduced overall survival (OS). MSI-high tumors were associated with significantly prolonged OS compared with MSI-low/microsatellite stable tumors. Transcriptome analysis revealed differentially expressed genes and enriched immune-related pathways in responders, though limited by sample size.

Conclusion: ca-4F12-E6 exhibited durable antitumor activity with manageable safety profile in dogs with OMM. Baseline systemic inflammatory markers and MSI status may serve as predictive biomarkers for clinical outcomes. The results support the use of canine OMM as a comparative model for human immuno-oncology and biomarker discovery.

Background: Oncolytic viruses are tumor-specific immunotherapeutic agents that exploit inherent features of the tumor microenvironment to replicate, spread, and kill cancer cells. The exchange protein activated by cAMP (EPAC) is a cell signaling protein that regulates pathways important for cell growth, survival, and migration, which are commonly associated with cancer progression, but are also very important for regulation of viral infectivity. EPAC antagonism has been explored as a broad-spectrum antiviral strategy, while selective EPAC activation with cAMP analogs has been found to increase virus replication and enhance therapeutic outcome of oncolytic virotherapy. However, systemic EPAC agonism bears risk of cardiovascular complications and may potentiate cancer progression.

Methods: A constitutively active construct of EPAC was encoded into an oncolytic vaccinia virus (VV) and screened using plaque assays, spheroid infections, and Transwell migration assays for its ability to enhance virus replication and spread. In vivo luminescence imaging, titering and immunohistochemical staining was used to measure virus dissemination in primary injected tumors and to track their spread to distal untreated tumors. The impact of the VV-EPAC virus on the immune landscape of MC38 tumors was investigated by flow cytometry, ELISPOTs and cytokine ELISAs, while its overall therapeutic efficacy was explored in MC38, CT26LacZ, and B16F10 models. Combinational synergy was also tested with capecitabine and oxaliplatin chemotherapy, as well as with partial surgical resection.

Results: The EPAC-expressing virus exhibited an increase in migrative ability both in cell culture and in vivo, due in part to remodeling of the actin cytoskeleton leading to intercellular nanotube-like structures and enhanced syncytia formation. It reduced tumor burden and increased survival in multiple colorectal cancer models and reshaped the tumor microenvironment by inducing angiogenesis and recruiting CD8+T cells. The EPAC-expressing virus also synergized with conventional chemotherapy and exhibited a remarkable therapeutic benefit when used together with surgical resection to treat a metastatic melanoma model. Despite the noted benefits that EPAC offers to virus and cancer growth, no significant increase in off-target replication, cytotoxicity, or disease progression was observed.

Conclusions: Altogether, the encoding of cellular signaling proteins into oncolytic viruses that modulate the intracellular and extracellular environments of tumors to create conditions favorable for virus replication and dissemination appears as a promising strategy to treat tumors and synergize with other conventional cancer therapies.

Background: Elevated levels of SPP1⁺ tumor-associated macrophages (TAMs) are associated with reduced CD8⁺ T cell infiltration and poorer prognosis in cancer patients, but direct evidence demonstrating a causal role for SPP1⁺ TAMs in excluding CD8⁺ T cells is still missing. The precise mechanisms by which SPP1-activated signaling pathways and macrophage-derived factors regulate CD8⁺ T cell trafficking remain poorly understood.

Methods: We established multiple tumor mouse models to study the function of macrophage SPP1 in the tumor environment, especially its role in the relationship between macrophages and CD8 T cells. We combined the single-cell (sc) RNA sequencing data of clinical tumor samples and tumor tissues from Spp1^{fl/fl-Lyz2-Cre} mice to identify the differences in SPP1-related genes and found that SPP1 could regulate the expression of CXCL9 and CXCL10 in macrophages. Through Western blotting, immunofluorescence staining, and flow cytometry analyses, we elucidated the mechanistic basis by which macrophage-specific SPP1 deficiency suppressed tumorigenesis.

Results: This study demonstrated that macrophage-derived SPP1 played a crucial role in suppressing CD8 T cell infiltration, promoting tumor progression, and diminishing the effectiveness of immune checkpoint inhibitor (ICI) therapy. Sc-RNA sequencing analysis revealed a marked increase in CD8 T cell populations within tumor tissues of Spp1^{fl/fl-Lyz2-Cre} mice. Furthermore, a negative correlation was observed between CD8 T cells and SPP1 macrophages in human colorectal cancer specimens. Genetic deletion of SPP1 in macrophages markedly enhanced tumor growth suppression in a manner dependent on CD8 T cell-mediated immunity. Mechanistically, SPP1 deficiency in macrophages led to elevated mitochondrial reactive oxygen species (ROS) production, resulting in the accumulation of cytosolic double-stranded DNA (dsDNA) fragments. This accumulated dsDNA activated the cGAS-STING pathway, leading to subsequent STAT1 phosphorylation. The enhanced STAT1 activity upregulated the expression of chemokines CXCL9 and CXCL10, thereby facilitating CD8 T cell recruitment into the tumor microenvironment.

Conclusions: Deletion of SPP1 in TAMs upregulates CXCL9/10 production by activating the ROS-DNA fragment/cGAS-STING/STAT1 pathway, thereby enhancing CD8 T cell infiltration, inhibiting tumor progression, and improving ICI treatment outcomes in tumors.

Background: Bispecific T cell engagers have demonstrated promising clinical progress in both hematologic malignancies and solid tumors; however, their therapeutic efficacy is still limited by multiple challenges including T cell anergy resulting from single-signal activation exclusively through CD3 engagement. As a critical co-stimulatory molecule, CD28 enhances T-cell functionality through synergistic interaction with the TCR-mediated primary activation signal, thus potentiating antitumor efficacy. Non-superagonistic CD28 bispecific antibodies, while enhancing antitumor efficacy, can minimize systemic toxicity. Kita-Kyushu Lung Cancer Antigen-1 (KK-LC-1), a cancer-testis antigen overexpressed in diverse malignancies, emerges as a promising target for tumor-specific immunotherapy. Herein, the development of a dual-signal T-cell engager strategy targeting KK-LC-1, using a non-superagonist CD28-based co-stimulatory mechanism, is of critical importance.

Methods: Based on the successful acquisition of the designed ankyrin repeat proteins targeting KK-LC-1 and CD28 through phage display technology (KD=8.985 nM and 7.43 nM), we designed two T cell engagers (KK-LC-1×CD3 and KK-LC-1×CD28). The tumor-specific binding activity of KK-LC-1 designed ankyrin repeat protein was verified by surface plasmon resonance, flow cytometry, confocal microscopy, and in vivo imaging. We then fused it with CD3 single-chain variable fragment and CD28-designed ankyrin repeat protein, respectively, to construct two T cell engagers. Their biological activities and antitumor efficacy were systematically evaluated both in vitro and in vivo (n=5) using flow cytometric analysis, confocal microscopy imaging, and bioluminescence quantification.

Results: T-cell engagers KK-LC-1×CD3 and KK-LC-1×CD28 were successfully engineered and demonstrated high binding affinity for both KK-LC-1-positive tumor cells and T cells. Co-administration of these engagers significantly augmented T-cell activation and antitumor efficacy (88% vs 66%, p<0.001) compared with KK-LC-1×CD3 monotherapy. In vivo, the combination suppressed tumor growth by 59.6% vs monotherapy (p<0.05) with enhanced intratumoral CD8⁺ infiltration (5.4-fold, p<0.001) and CD4⁺ infiltration (2.7-fold, p<0.001), while triple therapy incorporating PD-1×CTLA-4 bispecific antibodies extended median survival from 44 to 48 days (p<0.05).

Conclusions: We validated the feasibility of the KK-LC-1-targeted dual-signal T-cell engager strategy for the treatment of solid tumors and demonstrated that its combination with PD-1×CTLA-4 bispecific antibodies synergistically enhanced antitumor efficacy in preclinical studies.

Background: Although most studies of anticancer T-cell immunity focus on αβ T cells, γδ T cells are attracting increasing attention due to their involvement in antitumor immune responses in various cancer entities, including melanoma. While immune checkpoint blockade (ICB) using the antagonistic programmed cell death protein 1 (PD-1) antibodies nivolumab and pembrolizumab significantly improved the survival of patients with melanoma with distant metastasis, prognosis remains poor. PD-1 is not only expressed by αβ T cells but also by γδ T cells, making this numerically minor population of unconventional T cells, whose role in melanoma is still elusive, a target of ICB.

Methods: Here, we present a detailed γδ T-cell profiling study in late-stage melanoma at single-cell level using mass and polychromatic flow cytometry, T-cell receptor repertoire analyses and immunohistochemistry.

Results: Our analyses link high frequencies of peripheral Vδ1 T cells before the start of anti-PD-1 therapy to a significantly reduced overall survival. In these patients, the Vδ1 compartment is dominated by a late-differentiated senescent-like phenotype that is presumably unresponsive to therapy. This phenotype is less prevalent at the tumor site and analysis of RNA sequencing data revealed that the abundance of Vδ1 T cells within the tumor was positively associated with survival.

Conclusions: Our study suggests that Vδ1 T cells are associated with clinical outcomes, with a responsive subset expanding under ICB in patients where such a response remains possible. The observed clinical effects may be supported by the infiltration of these cells into the tumor, where they contribute to cancer immunosurveillance.

Background: While cancer vaccines have demonstrated promising clinical potential, their therapeutic efficacy against advanced tumors remains suboptimal, highlighting the critical need to elucidate resistance mechanisms and develop targeted solutions. We previously developed a stimulator of interferon genes (STING)-activating PC7A nanovaccine that elicits strong antitumor efficacy in multiple tumor models. In this study, we systematically investigated the mechanisms mediating nanovaccine resistance and provided targeting approaches to overcome this therapeutic barrier.

Methods: Vaccine efficacy at early stage and advanced-stage tumors was investigated in the B16-OVA melanoma model and TC-1 human papillomavirus-induced cancer model, with tumor microenvironment being comprehensively analyzed by flow cytometry. In a vaccine-resistant tumor, elevated immunosuppressive activity of polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) was assessed through multi-analysis including surface marker staining, reverse transcription-quantitative PCR, and functional T cell-suppression assay. To investigate the CD300ld blockade strategy, we employed CD300ld-knockout (KO) mice for genetic ablation, or recombinant protein capable of competitive inhibition for pharmacological intervention. For clinical relevance assessment, we tested different cancer vaccine formulations at late-stage tumors in humanized-CD3000ld mice.

Results: In contrast to early stage vaccination, PC7A nanovaccine administration at the late tumor stage exhibited minimal therapeutic effects on tumor progression, while concurrently increasing PMN-MDSC infiltration and enhancing their immunosuppressive activity. KO of CD300ld, a critical immune suppressor on PMN-MDSCs, abolished both PMN-MDSC recruitment and their T-cell suppressive function, restoring the antitumor efficacy of PC7A vaccine in multiple advanced tumor models. Furthermore, in wild-type and CD300ld humanized mouse models, competitive blockade of CD300ld using recombinant extracellular domain proteins overcame resistance of advanced tumors to different cancer vaccine formulations.

Conclusion: Our results reveal that vaccination at the late tumor stage significantly augments the recruitment and immunosuppressive capacity of PMN-MDSCs, driving resistance of advanced tumors to cancer vaccines. The findings demonstrate PMN-MDSCs as critical mediators of vaccine resistance in advanced tumors and highlight modulation of PMN-MDSCs by CD300ld blockade as a promising strategy to enhance the therapeutic efficacy of cancer vaccines, particularly for patients with late-stage malignancies.

Although immune checkpoint inhibitors (ICI) have greatly improved outcomes in several cancer types, their use is also associated with immune-related adverse events (irAEs) that can impact any organ system and lead to significant morbidity and even mortality. Current approaches to treatment of irAEs largely rely on the use of systemic corticosteroids, which can compromise antitumor immune responses and oncologic outcomes. Prolonged use of systemic corticosteroids is also associated with its own set of toxicities. Thus, there is a critical need for steroid-sparing treatment approaches for irAEs.In this article, we review the literature for alternative therapeutic approaches for irAEs, which include targeted delivery (alternate routes of administration) of steroids (eg, budesonide) as well as systemic non-steroidal strategies using other mechanisms of action, such as integrin/cytokine blockade, antibody depletion, disease-modifying antirheumatic drugs and fecal microbiota transplant, among others. Many of these approaches have shown significant promise in their ability to induce a clinical response and improve symptoms, even in the setting of steroid-refractory or steroid-dependent irAEs. These approaches are being increasingly used as primary and secondary prophylaxis in patients at high risk of irAEs. Importantly, these strategies may mitigate steroid-associated toxicities, preserve antitumor immune responses and allow continuation of ICI after development of irAEs, hence enabling the full potential of ICI against cancer.