Journal for Immunotherapy of Cancer最新文献

Background: Glucose deprivation inhibits T-cell metabolism and function. Glucose levels are low in the tumor microenvironment of solid tumors and insufficient glucose uptake limits the antitumor response of T cells. Furthermore, glucose restriction can contribute to the failure of chimeric antigen receptor T (CAR-T) cell therapy for solid tumors. However, the impact of glucose restriction remains unknown in CAR-T cell therapy.

Methods: Glucose transporters were detected and overexpressed in CAR-T cells. The impacts of glucose restriction on CAR-T cells were checked in vitro and in vivo.

Results: Glucose restriction significantly decreased CAR-T cell activation, effector function, and expansion. CAR-T cells expressed high levels of the glucose transporter Glut1, which has a low affinity for glucose. Overexpression of Glut1 failed to improve CAR-T cell function under glucose-restricted conditions. In contrast, the function and antitumor potential of CAR-T cells was enhanced by the overexpression of Glut3, which has the highest affinity for glucose among the Glut transporter family and is expressed in minor parts of CAR-T cells. Glut3-overexpressing CAR-T cells demonstrated increased tumoricidal efficacy in multiple xenografts and syngenetic mouse models. Furthermore, Glut3 overexpression activated the PI3K/Akt pathway and increased OXPHOS and mitochondrial fitness.

Conclusions: We provide a direct and effective approach to enhance low glucose uptake levels by CAR-T cells and improve their antitumor efficacy against solid tumors.

Cancer immunotherapy-including immune checkpoint inhibition (ICI) and adoptive cell therapy (ACT)-has become a standard, potentially curative treatment for a subset of advanced solid and liquid tumors. However, most patients with cancer do not benefit from the rapidly evolving improvements in the understanding of principal mechanisms determining cancer immune responsiveness (CIR); including patient-specific genetically determined and acquired factors, as well as intrinsic cancer cell biology. Though CIR is multifactorial, fundamental concepts are emerging that should be considered for the design of novel therapeutic strategies and related clinical studies. Recent advancements as well as novel approaches to address the limitations of current treatments are discussed here, with a specific focus on ICI and ACT.

Background: Intratumoral oncolytic herpes simplex virus 2-GM CSF (OH2) injection has shown safety and antitumor efficacy in patients with solid tumors. Here, we examined the safety and efficacy of OH2 as a single agent or in combination with HX008, an NMPA-approved PD-1 inhibitor, in locally advanced or metastatic sarcoma patients.

Methods: This multicenter, phase 1/2 trial enrolled patients with injectable sarcoma lesions, who had failed at least 1 or more lines of standard treatment. Patients were treated with OH2 at three dose levels (10⁶, 10⁷ and 10⁸ CCID₅₀/mL) as single agent or in combination with a fixed dose of HX008. The primary endpoints were safety and tolerability in phase 1 and objective response rate determined by RECIST (V.1.1) criteria and immune-RECIST in phase 2.

Results: Between October 20, 2020 and December 30, 2023, 26 patients were enrolled. Seven patients were treated with single-agent OH2 and 19 with HX008 and OH2 combination. No dose-limiting toxicities were observed during the dose escalation. We documented four partial or complete responses in injected lesions, and one partial response in non-injected lesions, which were all from the combination group. Hence, the overall response rate was 0% and 16.7% in the single agent and combination groups, respectively. The duration of response was 3.9-6.5 months. The most frequent treatment-related adverse events (TRAEs) were fever (n=9). Grade 3 or 4 TRAEs were reported in four patients (15.4%). A clear increase in CD8+cell density in the tumor microenvironment was observed in the patients' post-treatment specimens compared with baseline.

Conclusions: Intratumoral injection of oncolytic virus OH2 is well tolerable in patients with sarcoma. Further investigation of OH2 with HX008 in select sarcoma subtypes is warranted.

Chimeric antigen receptor (CAR) T cell therapy of solid cancer remains below expectations; adding cytokine help through IL-18 has shown remarkable efficacy in first clinical trials. As IL-18 is also a powerful driver of hyperinflammatory conditions, we discuss to what extent unleashing IL-18 is a double-edged sword in CAR T cell therapies.

Background: Adaptive cellular therapy (ACT), particularly chimeric antigen receptor (CAR)-T cell therapy, has been successful in the treatment of hemopoietic malignancies. However, poor trafficking of administered effector T cells to the tumor poses a great hurdle for this otherwise powerful therapeutic approach in solid cancers. Our previous study revealed that targeting CD93 normalizes tumor vascular functions to improve immune checkpoint blockade therapy. The objective of this study is to evaluate whether CD93 blockade improves ACT in solid cancers.

Methods: Monoclonal antibodies (mAbs) against CD93 or IGFBP7 were administered in implanted mouse melanoma models to assess the effect of CD93 blockade on ACT. Different sources of effector T cells were used, including pre-activated CD8+OT-1, pmel-1 transgenic T cells, and CAR-T cells. Rip-OVA and Rip-TAG-OVA transgenic mice were used to evaluate the selective impact of CD93 blockade on effector T-cell infiltration in tumors. For mechanistic studies, vascular maturation was determined by immunofluorescent staining and flow cytometry was performed to examine tumor-infiltrating T lymphocytes. Neutralizing mAbs against adhesion molecules ICAM1 and VCAM1 were infused to assess their involvement.

Results: Blockade of the CD93 pathway increases the expression of adhesion molecules on tumor vasculature to improve effector T-cell infiltration and function. T-cell transfer and CD93 blockade synergistically improve tumor vascular maturation, as well as inhibit tumor progression. Anti-CD93 selectively promotes effector T-cell infiltration in a tumorous setting where the CD93 pathway is upregulated. In a solid mouse tumor model, blockade of the CD93 pathway improves CAR-T therapy.

Conclusions: CD93 blockade normalizes tumor vasculature leading to improved effector T-cell infiltration and function in solid cancers. Our study advocates the application of CD93 blockade for ACT in solid cancers.

Purpose: Anti-programmed cell death 1 (PD1) is the first-choice treatment in patients with advanced cutaneous squamous cell carcinoma (cSCC), when curative options are unavailable. However, reliable biomarkers for patient selection are still lacking.

Experimental design: In this translational study, clinical annotations, tissue and liquid biopsies were acquired to investigate the association between sustained objective responses and transcriptional profiles, immune cell dynamics in tumor tissue and peripheral blood samples, as well as circulating cytokine levels.

Results: First, we investigated the baseline characteristics of the immune landscape of cSCC biopsies. Gene Set Enrichment Analysis showed upregulation of interleukin (IL)2/STAT5 pathways and downregulation of Interferon signatures in non-responder patients compared with responders. Next, we studied the early changes induced by cemiplimab in tissue biopsies. Notably, after only three weeks, cemiplimab treatment induced an increase in B cells and CD8+ T cells in responders, whereas their abundance decreased in non-responder patients. Moreover, analyzing differentially expressed genes modulated early during treatment, compared with baseline biopsies, we found that IL1β and IL8 exhibited early downregulation in responder patients' tumor specimens. We assessed whether changes in the local tumor microenvironment were mirrored in peripheral blood. Similar to tissue findings, no changes were observed in the whole T regulatory (Treg) population, although PD1+ Tregs, which were downregulated in responder patients (vs T0), showed a rebound enrichment in non-responders after three cycles of cemiplimab. Finally, IL8 mirrored the tissue results, unlike IL1β, with early (T1) and then sustained (T3) downregulation of its levels in responder patients, while increased in non-responders.

Conclusions: Taken together, these findings shed light on the significance of early transcriptomic and immune cell modulation in predicting responses to cemiplimab therapy. Additionally, our data suggest that IL8 levels in peripheral blood offer promising avenues for personalized treatment selection and response assessment in patients with cSCC receiving cemiplimab, while PD1+Tregs can be followed longitudinally to monitor response to therapy.

Background: The efficacy of immune checkpoint inhibitors (ICIs) depends on the tumor immune microenvironment (TIME), with a preference for a T cell-inflamed TIME. However, challenges in tissue-based assessments via biopsies have triggered the exploration of non-invasive alternatives, such as radiomics, to comprehensively evaluate TIME across diverse cancers. To address these challenges, we develop an ICI response signature by integrating radiomics with T cell-inflamed gene-expression profiles.

Methods: We conducted a pan-cancer investigation into the utility of radiomics for TIME assessment, including 1360 tumors from 428 patients. Leveraging contrast-enhanced CT images, we characterized TIME through RNA gene expression analysis, using the T cell-inflamed gene expression signature. Subsequently, a pan-cancer CT-radiomic signature predicting inflamed TIME (CT-TIME) was developed and externally validated. Machine learning was employed to select robust radiomic features and predict inflamed TIME. The study also integrated independent cohorts with longitudinal CT images, baseline biopsies, and comprehensive immunohistochemistry panel evaluation to assess the pan-cancer biological associations, spatiotemporal landscape and clinical utility of the CT-TIME.

Results: The CT-TIME signature, comprising four radiomic features linked to a T-cell inflamed microenvironment, demonstrated robust performance with AUCs (95% CI) of 0.85 (0.73 to 0.96) (training) and 0.78 (0.65 to 0.92) (external validation). CT-TIME scores exhibited positive correlations with CD3, CD8, and CD163 expression. Intrapatient analysis revealed considerable heterogeneity in TIME between tumors, which could not be assessed using biopsies. Evaluation of aggregated per-patient CT-TIME scores highlighted its promising clinical utility for dynamically assessing the immune microenvironment and predicting immunotherapy response across diverse scenarios in advanced cancer. Despite demonstrating progression disease at the first follow-up, patients within the inflamed status group, identified by CT-TIME, exhibited significantly prolonged progression-free survival (PFS), with some surpassing 5 months, suggesting a potential phenomenon of pseudoprogression. Cox models using aggregated CT-TIME scores from baseline images revealed a statistically significant reduction in the risk of PFS in the pan-cancer cohort (HR 0.62, 95% CI 0.44 to 0.88, p=0.007), and Kaplan-Meier analysis further confirmed substantial differences in PFS between patients with inflamed and uninflamed status (log-rank test p=0.009).

Conclusions: The signature holds promise for impacting clinical decision-making, pan-cancer patient stratification, and treatment outcomes in immune checkpoint therapies.

Introduction: Immune checkpoint inhibitors (ICI) have improved outcomes in non-small cell lung cancer (NSCLC). Nevertheless, the clinical benefit of ICI as monotherapy or in combination with chemotherapy remains widely varied and existing biomarkers have limited predictive value. We present an analysis of ENLIGHT-DP, a novel transcriptome-based biomarker directly from histopathology slides, in patients with lung adenocarcinoma (LUAD) treated with ICI and platinum-based chemotherapy.

Methods: We retrospectively scanned high-resolution H&E slides from pretreatment tumor-tissue samples of 50 patients with metastatic LUAD treated with first-line ICI with (46) or without (4) platinum-based chemotherapy and applied our ENLIGHT-DP pipeline to generate, in a blinded manner, an individual prediction score. ENLIGHT-DP predicts response to ICI and targeted therapies given H&E slide scans in two steps: (1) predict individual messenger RNA expression directly from high-resolution H&E scanned slides using DeepPT, a digital-pathology-based algorithm. (2) Use these values as input to ENLIGHT, a transcriptome-based platform that predicts response to ICI and targeted therapies derived from drug-specific networks of gene expressions. We then unblinded the clinical outcomes and evaluated the predictive value of ENLIGHT-DP in comparison to programmed death ligand (PD-L)-1 and tumor mutational burden (TMB).

Results: ENLIGHT-DP is predictive of response to treatment with receiver operating characteristic (ROC) area under the curve (AUC) of 0.69 (p=0.01) and outperforms both TMB and PD-L1 expression with ROC AUC of 0.52 and 0.46, respectively. Using a predetermined binary cut-off (established on independent cohorts) for patients predicted to respond to ICI, ENLIGHT-DP achieves 100% positive predictive value (PPV) and 44% sensitivity, superior to both PD-L1>50% (65% PPV and 38% sensitivity) and TMB-high (82% PPV and 26% sensitivity). ENLIGHT-DP was highly predictive in PD-L1<1% and TMB-low outlier groups with ROC AUC of 0.88 and 0.80, respectively (p value<0.05). ENLIGHT-DP is the only biomarker in this cohort significantly correlated with progression-free survival (HR: 0.45, 95% CI: 0.2 to 0.99, p=0.048).

Conclusion: We demonstrate the application of ENLIGHT-DP, a transcriptome-based biomarker for accurate prediction of treatment of LUAD with ICI and platinum-based chemotherapy, outperforming PD-L1 and TMB, and relying solely on accessible H&E scanned slides. Further studies on different tumor types, ICI monotherapy and bigger NSCLC cohorts are warranted.

Background: CD3 bispecific antibody (CD3 bsAb) therapy has become an established treatment modality for some cancer types and exploits endogenous T cells irrespective of their specificity. However, durable clinical responses are hampered by immune escape through loss of tumor target antigen expression. Induction of long-lasting tumor-specific immunity might therefore improve therapeutic efficacy, but has not been studied in detail yet for CD3 bsAbs. Here, we examined multiple combination strategies aiming to improve survival rates in solid tumors and, simultaneously, install endogenous immunity capable of protection to tumor rechallenge.

Methods: Two syngeneic mouse tumor models were employed: The immunologically "cold" B16F10 melanoma and the immunologically "hot" MC38.TRP1 colon carcinoma model. Mice were treated with CD3xTRP1 bsAb (murine Fc-inert immunoglobulin G2a) as monotherapy, or in combination with agonistic costimulatory antibodies, Fc-active tumor-opsonizing antibodies, or tumor-(non)specific vaccines. Treatment efficacy of primary tumors and protection from rechallenge was monitored, as well as induction of tumor-specific T-cell responses.

Results: In the immunologically "cold" B16F10 model, all combination therapies improved antitumor activity compared with CD3 bsAb monotherapy and induced systemic tumor-specific T-cell responses. However, this endogenous T-cell immunity swiftly waned and failed to protect mice from subsequent tumor rechallenge, except for combination therapy with tumor-specific vaccination. These vaccines strongly improved the therapeutic efficacy of CD3 bsAb against primary tumors and led to long-term immunological protection. In the immunologically "hot" MC38.TRP1 model, CD3 bsAb combined with only the vaccine adjuvant was sufficient to generate protective T-cell immunity and, moreover, prevented tumor escape via antigen loss.

Conclusions: These results demonstrate the impact of tumor antigenicity on the induction of protective endogenous antitumor immunity during CD3 bsAb treatment and, importantly, show that the combination with tumor-specific vaccines improves therapeutic efficacy and installs long-term immunological memory in both "hot" and "cold" tumors.

Background: SL-172154 is a hexameric fusion protein adjoining the extracellular domain of SIRPα to the extracellular domain of CD40L via an inert IgG₄-derived Fc domain. In preclinical studies, a murine equivalent SIRPα-Fc-CD40L fusion protein provided superior antitumor immunity in comparison to CD47- and CD40-targeted antibodies. A first-in-human phase I trial of SL-172154 was conducted in patients with platinum-resistant ovarian cancer.

Methods: SL-172154 was administered intravenously at 0.1, 0.3, 1.0, 3.0, and 10.0 mg/kg. Dose escalation followed a modified toxicity probability interval-2 design. Objectives included evaluation of safety, dose-limiting toxicity, recommended phase II dose, pharmacokinetic (PK) and pharmacodynamic (PD) parameters, and antitumor activity.

Results: 27 patients (median age 66 years (range, 33-85); median of 4 prior systemic therapies (range, 2-9)) with ovarian (70%), fallopian tube (15%), or primary peritoneal (15%) cancer received SL-172154. Treatment-emergent adverse events (TEAEs) were reported for 27 patients (100%), with 24 (88.9%) having a drug-related TEAE and infusion-related reactions being the most common. 12 patients (44.4%) had grade 3/4 TEAEs, and half of these patients (22.2%) had a drug-related grade 3/4 TEAE. There were no fatal adverse events, and no TEAEs led to drug discontinuation. SL-172154 C_max and area under the curve increased with dose with greater than proportional exposure noted at 3.0 and 10.0 mg/kg. CD47 and CD40 target engagement on CD4⁺ T cells and B cells, respectively, approached 100% by 3.0 mg/kg. Dose-dependent responses in multiple cytokines (eg, interleukin 12 (IL-12), IP-10) approached a plateau at ≥3.0 mg/kg. Paired tumor biopsies demonstrated a shift in macrophages from an M2- to an M1-dominant phenotype and increased infiltration of CD8 T cells. PK/PD modeling showed near maximal margination of B cells and a dose-dependent production of IL-12 nearing a plateau at >3.0 mg/kg. The best response was stable disease in 6/27 (22%) patients.

Conclusions: SL-172154 was tolerable as monotherapy and induced, dose-dependent, and cyclical immune cell activation, increases in multiple serum cytokines, and trafficking of CD40-positive B cells and monocytes following each infusion. The safety, PK, and PD activity support 3.0 mg/kg as a safe and pharmacologically active dose.

Trial registration number: NCT04406623.