Non-small cell lung cancer (NSCLC) is a fatal disease, and radioresistance is an important factor leading to treatment failure and disease progression. The objective of this research was to detect radioresistance-related genes (RRRGs) with prognostic value in NSCLC.

The weighted gene coexpression network analysis (WGCNA) and differentially expressed genes (DEGs) analysis were performed to identify RRRGs using expression profiles from TCGA and GEO databases. The least absolute shrinkage and selection operator (LASSO) regression and random survival forest (RSF) were used to screen for prognostically relevant RRRGs. Multivariate Cox regression was used to construct a risk score model. Then, Immune landscape and drug sensitivity were evaluated. The biological functions exerted by the key gene LBH were verified by in vitro experiments.

Ninety-nine RRRGs were screened by intersecting the results of DEGs and WGCNA, then 11 hub RRRGs associated with survival were identified using machine learning algorithms (LASSO and RSF). Subsequently, an eight-gene (APOBEC3B, DOCK4, IER5L, LBH, LY6K, RERG, RMDN2 and TSPAN2) risk score model was established and demonstrated to be an independent prognostic factor in NSCLC on the basis of Cox regression analysis. The immune landscape and sensitivity to anti-tumour drugs showed significant disparities between patients categorized into different risk score subgroups. In vitro experiments indicated that overexpression of LBH enhanced the radiosensitivity of A549 cells, and knockdown LBH reversed the cytotoxicity induced by X-rays.

Our study developed an eight-gene risk score model with potential clinical value that can be adopted for choice of drug treatment and prognostic prediction. Its clinical routine use may assist clinicians in selecting more rational practices for individuals, which is important for improving the prognosis of NSCLC patients. These findings also provide references for the development of potential therapeutic targets.

Radiation therapy can be categorised by particle type into photon, proton and heavy ion therapies. Proton radiotherapy is highlighted due to its unique physical properties, such as the Bragg peak and minimal exit dose, which offer superior dose distribution. This makes proton radiotherapy especially advantageous for treating tumours near vital organs with complex structures, such as gliomas near the brain, nasopharyngeal carcinoma near the brainstem and mediastinal tumours near the heart. Proton irradiation can induce distant effects through immunogenicity within the target area. The reduced low-dose zone outside the target provides better lymphatic system protection and immune benefits. Additionally, combining proton radiotherapy with immunotherapy may offer further biological advantages. These features make proton radiotherapy a promising option in cancer treatment. This article may aid in the understanding of proton radiotherapy and its immune effects and lead to new effective options for tumour treatment.

Currently, cancer immunotherapy strategies are primarily formulated based on the patient's present condition, representing a "static" treatment approach. However, cancer progression is inherently "dynamic," as the immune environment is not fixed but undergoes continuous changes. This dynamism is characterized by the ongoing interactions between tumor cells and immune cells, which ultimately lead to alterations in the tumor immune microenvironment. This process can be effectively elucidated by the concept of cancer immunoediting, which divides tumor development into three phases: "elimination," "equilibrium," and "escape." Consequently, adjusting immunotherapy regimens based on these distinct phases may enhance patient survival and improve prognosis. Targeting ferroptosis is an emerging area in cancer immunotherapy, and our findings reveal that the antioxidant systems associated with ferroptosis possess dual roles, functioning differently across the three phases of cancer immunoediting. Therefore, this review delve into the dual role of the ferroptosis antioxidant system in tumor development and progression. It also propose immunotherapy strategies targeting ferroptosis at different stages, ultimately aiming to illuminate the significant implications of targeting ferroptosis at various phases for cancer immunotherapy.

Melanoma, known for its aggressive behavior and tendency to metastasize to the brain and lungs, is a formidable challenge in oncology. Radiotherapy is a potent treatment for localized solid tumors, effective against both intracranial and extracranial metastases. Yet, some melanoma patients exhibit substantial resistance to radiotherapy, with the underlying mechanisms of this resistance remaining elusive. While radiotherapy can stimulate the infiltration of immune cells, thereby triggering a range of immunostimulatory effects, it can also suppress the tumor microenvironment (TME), limiting its effectiveness. In physiological conditions, cytokines inhibit the activity of immunosuppressive cells through paracrine and autocrine signaling, while also activating immune cells to boost antitumor responses. Here, we found that Interleukin (IL)-21 expression was higher in the mice with good radiotherapy response to melanoma than in the mice with poor radiotherapy response. Interestingly, we also observed the higher infiltration of M2 TAMs and lower CD8+ T cells in the group with poor radiotherapy response. To tackle this issue, we explored the therapeutic potential of a plasmid encoding IL-21, delivered via attenuated Salmonella, in mice bearing melanomas. Our findings revealed that IL-21 administration significantly reduced M2 TAMs infiltration and enhanced CD8+ T cells infiltration and granzyme B (GZMB) expression within melanoma tumors. Most importantly, the combination of IL-21 with radiotherapy led to markedly tumor reduction compared to either treatment alone. This research highlights the potential of IL-21 as a valuable adjunct to radiotherapy in the treatment of melanoma, presenting a promising strategy for enhancing antitumor immune responses and optimizing patient outcomes.

Although the combination of radiotherapy and immunotherapy is regarded as a promising clinical treatment strategy, numerous clinical trials have failed to demonstrate synergistic effects. One of the key reasons is that conventional radiotherapies inevitably damage intratumoral effector immune cells. Boron Neutron Capture Therapy (BNCT) is a precise radiotherapy that selectively kills tumor cells while sparing adjacent normal cells, by utilizing 10B agents and neutron irradiation. Therefore, combinational BNCT-immunotherapy holds promise for achieving more effective synergistic effects. Here it develops a 10B-containing polymer that self-assembled with PD-L1 siRNA to form 10B/siPD-L1 nanoparticles for combinational BNCT-immunotherapy. Unlike antibodies, PD-L1 siRNA can inhibit intracellular PD-L1 upregulated by BNCT, activating T-cell immunity while also suppressing DNA repair. This can enhance BNCT-induced DNA damage, promoting immunogenic cell death (ICD) and further amplifying the antitumor immune effect. The results demonstrated that BNCT using 10B/siPD-L1 nanoparticles precisely killed tumor cells while sparing adjacent T cells and induced a potent antitumor immune response, inhibiting distal and metastatic tumors.

Targeted delivery of glucose oxidase (GOx) using MXene remains a great challenge due to its poor dispersion and susceptibility to oxidation, and the hypoxia and high glutathione (GSH) contents make the situation even more worrying. Herein, a bovine serum albumin-mediated non-chemical modification strategy is developed, endowing titanium carbide MXene with long-time water-dispersion and further integrating it as a glycolysis-controllable therapy system without any chemotherapeutic agents. The system also constructs an effective O2 cycling and GSH degradation pathway, which fundamentally adjusts the tumor microenvironment and greatly elevates both in vivo and in vitro therapy effects. Reactive oxygen species are also generated and disrupt the balance of oxidative stress. Moreover, the reduced efficiency of mitochondrial energy production significantly inhibits the level of glycolysis and hinders energy supply. The study presents an effective cancer treatment combining starvation/photothermal therapy, which has superior anti-cancer effects due to the dual effects of reducing glucose levels and diminishing cellular energy production capacity.

Radiotherapy efficacy remains constrained by two key challenges: dose-dependent toxicity to healthy tissues at high radiation doses and hypoxia-mediated tumor radioresistance. While radiosensitizers like gold nanoparticles can enhance tumor-specific radiation deposition, their targeted delivery to tumors presents a significant hurdle. Bacteria have emerged as promising bio-carriers that not only actively target tumors and penetrate complex microenvironments, but can also be genetically engineered as multifunctional platforms for radiosensitizer delivery and hypoxia alleviation.

An integrated nanosystem (PCM@AuNPs), composed of engineered bacteria (PCM) and gold nanoparticles (AuNPs), is used to increase the effectiveness of radiotherapy. PCM can target and colonize tumor sites more effectively, thus improving the delivery efficiency of radiosensitizers. Furthermore, PCM overexpresses catalase (CAT), which decomposes excess H2O2 into O2, helping to mitigate hypoxia in the TME. Under X-ray irradiation, PCM@AuNPs significantly enhance radiosensitization, leading to improved tumor growth inhibition while maintaining good biocompatibility.

An effective strategy based on an integrated nanosystem (PCM@AuNPs) for radiosensitization through multiple pathways is developed. This novel engineered bacterial strategy holds great promise for enhancing radiosensitization in cancer therapy.

Colorectal cancer (CRC) is still one of the leading causes of cancer deaths worldwide. Even though there has been progress in cancer immunotherapy, the results of applying immune checkpoint inhibitors (ICIs) have been unsatisfactory, especially in microsatellite stable (MSS) CRC. Single-agent ICIs that target programmed cell death-1 (PD-1)/ PD-L1, cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), T cell Ig- and mucin-domain-containing molecule-3 (TIM-3), and lymphocyte activation gene (LAG)-3 have emerged as having specific benefits. However, many primary and secondary resistance mechanisms are available in the tumor microenvironment (TME) that prevent it from happening. Combination strategies, such as the use of anti-PD-1 and anti-CTLA-4, can be effective in overcoming these resistance pathways, but toxicities remain a significant concern. Moreover, ICIs have been integrated with various treatment modalities, including chemotherapy, radiotherapy, antibiotics, virotherapy, polyadenosine diphosphate-ribose polymerase (PARP) inhibitors, and heat shock protein 90 (HSP90) inhibitors. The outcomes observed in both preclinical and clinical settings have been encouraging. Interestingly, manipulating gut microbiota via fecal microbiota transplantation (FMT) has been identified as a new strategy to increase the efficacy of immunotherapy in CRC patients. Therefore, integrating ICIs with other treatment approaches holds promise in enhancing the prognosis of CRC patients. This review focuses on the unmet need for new biomarkers to select patients for combination therapies and the ongoing work to overcome resistance and immune checkpoint blockade.

Prostate-specific membrane antigen targeted radionuclide therapies (PSMA-TRT) such as 177Lu-PSMA-617 hold great promise in improving clinical outcomes at various stages of prostate cancer. The FDA approval of 177Lu-PSMA-617 represents a significant advancement in the treatment of metastatic castration-resistant prostate cancer (mCRPC). The VISION trial demonstrated improved radiographic progression-free survival (rPFS) and overall survival (OS) with 177Lu-PSMA-617 in patients with mCRPC who had already receive androgen receptor pathway inhibitor (ARPI) and taxane chemotherapy. Exploration of 177Lu-PSMA-617 in earlier stages of prostate cancer, such as in the PSMAfore trial for patients who have not received chemotherapy, holds great promise for improving long-term outcomes and delaying exposure to chemotherapy. Combining 177Lu-PSMA-617 with other therapies, including chemotherapy, PARP inhibitors, and immunotherapy, is an area of active investigation. This review will also discuss alternative radionuclides (such as actininum-225 and terbium-161) and delivery vehicles (such as PSMA-I&T), which we find promising. Predictive biomarkers and dosimetry will be crucial for identifying patients most likely to benefit from PSMA-TRT. Continued research and refinement of these therapies will lead to PSMA-targeted treatments becoming an integral part of prostate cancer management.

Irreversible electroporation (IRE) and stereotactic ablative body radiotherapy (SABR) are cytoreductive therapies for locally advanced pancreatic cancer (LAPC). Both may signify immunogenic cell death. We aimed to compare systemic immune responses between the treatments.

As part of the randomized phase II CROSSFIRE trial (NCT02791503), comparing the oncological efficacy of IRE to SABR in patients with LAPC, pre- and post-treatment (2 weeks and 3 months) peripheral blood samples were collected. Frequency and activation status of lymphocytic and myeloid subsets were determined using flow cytometry. T cell responses to pancreatic cancer associated with Wilms tumor-1 (WT-1) and survivin tumor antigens were determined by interferon-γ enzyme-linked immunospot assay.

In total, 20 IRE and 20 SABR-treated participants were analyzed (20 men; median age 65 (IQR 55-70)). IRE induced immediate decreases in systemic regulatory T cell (Treg) and conventional type-1 dendritic cell rates, coinciding with CD4+/CD8+ T cell activation by upregulation of PD-1, which was associated with improved overall survival (OS). SABR similarly induced immediate CD4+/CD8+ T cell activation by upregulation of Ki67 and CD25 but resulted in asynchronously delayed Treg downregulation. SABR also induced a durable increase in CD4+ EM T cells, associated with improved OS. Ablation-induced WT-1 or survivin-specific T cell responses were observed in 9/16 (56%) immune competent participants (IRE n=5, SABR n=4) and were associated with longer OS.

Distinct immune stimulatory responses associated with improved OS, suggest that SABR might benefit from combined Treg depletion strategies while IRE could benefit from PD-1 checkpoint inhibition.

The trial was registered on clinical trials.gov (NCT02791503).

The purpose of this study was to investigate the efficacy and safety of tislelizumab (monoclonal antibody) plus anlotinib (tyrosine kinase inhibitor) with or without radiotherapy in advanced hepatocellular carcinoma (HCC). Ninety patients with advanced HCC were divided into two groups: tislelizumab plus anlotinib with radiotherapy (TAR group) and tislelizumab plus anlotinib (TA group) based on the treatment received. Radiotherapy was performed on two or three days during the first cycle of tislelizumab plus anlotinib. The radiotherapy requirements were dose95% ≥ 14.2-46 Gy for tumor volume. Efficacy was evaluated according to the modified Response Evaluation Criteria for Solid Tumors. Adverse events (AEs) were evaluated using the National Cancer Institute-Common Terminology Criteria for Adverse Events 4.0. The primary endpoint was the objective response rate (ORR). The secondary endpoints were progression-free survival (PFS), overall survival (OS), and the disease control rate (DCR). The ORR and DCR in the TAR group were 24.5% (62.2% and 37.7%, p = 0.03) and 22.3% higher (75.6% and 53.3%, p = 0.04), respectively, compared to the TA group. The median OS and PFS in the TAR group were prolonged 4.5 months [21.0 and 16.5 months, χ2 = 8.99, p = 0.00, 95% confidence interval (CI) 0.295-0.774] and 4.0 months (11.0 and 7.0 months. χ2 = 11.73, p = 0.00. 95% CI 0.989-2.502), respectively, compared to the TA group. The risks of disease progression and mortality in the TAR group were reduced by 53.0% (hazard ratio (HR) = 0.470, 95% CI 0.294-0.753) and 49.3% (HR = 0.507, 95% CI 0.315-0.815) compared to the TA group. The OS and PFS rates at 1 and 2 years increased by 28.9% (97.8% and 68.9%, p = 0.00) and 20.0% (42.2% and 22.2%, p = 0.07) and 28.9% (42.2% and 13.3%, p = 0.00) and 15.6% (20.0% and 4.4%, p = 0.05), respectively, in the TAR group compared to the TA group. Most patients mainly presented with grade 1/2 tolerable acute AEs (p > 0.05). No AEs were related to radiotherapy, and no fatalities occurred. The results indicate that tislelizumab plus anlotinib and radiotherapy is a safe and effective treatment for advanced HCC. Trial registration: ChiCTR2000039022 (10/13/2020). Retrospective.

Ionizing radiation can influence the antitumor immune response, either activating or suppressing the immune system depending on the tumor type and radiotherapy modality. While photon radiation (RT) combined with immunotherapy (IT) is widely studied in clinical trials, proton radiation (PT) combined with IT has not been thoroughly investigated in clinical or preclinical studies despite its radiobiological advantages. This study aims to explore the immune effects of a hypofractionated PT scheme compared to RT and its efficacy with anti-PD-L1 immunotherapy.

Balb/c mice bearing subcutaneous CT26 colon tumors were treated with RT or PT, delivered with 3 × 8 Gy. Seven days post-treatment, transcriptomic analysis and immune response assessments to characterize lymphoid cells, myeloid cells, and PD-L1 expression were performed. Tumor growth was monitored to evaluate the efficacy of combining RT or PT with anti-PD-L1 IT.

The RNA sequencing analysis demonstrated an overexpression of genes involved in the interferon type I pathway after both RT and PT. Tumor microenvironment analysis showed enhanced immune cell infiltration in tumors after both treatments. Immunoactivating cells infiltration was observed, with LT CD8 + cells infiltration after both RT and PT, more significantly after RT. NK and TAM1 cells infiltrated only after RT. Immunosuppressive cell populations were induced by PT, including MDSCs, while Tregs infiltrated both RT and PT treated tumors. PD-L1 expression was significantly induced only by RT. The combination of anti-PD-L1 with RT or PT resulted in tumor growth delay compared to RT or PT alone, with a significant survival benefit observed only after the combination of RT and IT.

This study demonstrates that hypofractionated RT and PT induced both similar and significantly distinct immune responses. PT triggers a stronger immunosuppressive response than RT. Optimizing the combination of PT with IT, including dose, fractionation, and sequencing is crucial for improving treatment efficacy.

The abscopal effect of radioimmunotherapy, wherein tumor shrinkage occurs beyond the irradiated field, is therapeutically promising but clinically rare. The mechanisms underlying this effect remain elusive. Here, in vivo genome-wide CRISPR screening identifies SFRP2 as a potential stromal regulator of the abscopal effect. SFRP2 exhibits cancer-associated fibroblast (CAF)-specific expression and radioimmunotherapy-mediated upregulation in unirradiated tumors. Conditional Sfrp2 knockout in CAFs boosts the abscopal effect by rewiring the vascular-immune microenvironment to promote CD8+ T cell recruitment to unirradiated tumors. In vivo lineage tracing reveals that elevated SFRP2 correlates with radioimmunotherapy-driven pericyte lineage commitment. Serum proteomics reveals that irradiated-tumor-secreted PAI-1 triggers distant tumor pericyte cell-fate transition into SFRP2high CAFs via the LRP1/p65 axis. Pharmacologically blocking SFRP2 or PAI-1 enhances the abscopal effect in humanized patient-derived xenograft models. Our findings collectively illustrate that PAI-1-induced SFRP2high CAFs serve as critical stromal regulator to hijack the abscopal effect, providing promising targets for enhancing radioimmunotherapy effectiveness.

The radiotherapy-induced release of DNA fragments can stimulate the cyclic guanosine monophosphate-adenosine monophosphate synthase-stimulator of interferon genes (cGAS-STING) pathway to prime antitumor immunity, but this pathway is expected to be less potent because of the inefficient cytosolic delivery of negatively charged DNA fragments. In this study, manganese-coordinated chitosan (CS-Mn) microparticles with selective DNA-capturing capacity are concisely prepared via a coordination-directed one-pot synthesis process to potentiate the immunogenicity of radiotherapy. The obtained CS-Mn microparticles that undergo rapid disassembly under physiological conditions can selectively bind with DNA to form positively charged DNA-CS assemblies because of the strong electrostatic interaction between linear chitosan and DNA molecules. They thus enable efficient cytosolic delivery of DNA in the presence of serum to cooperate with Mn2+ to activate the cGAS-STING pathway in dendritic cells. Upon intratumoral injection, the CS-Mn microparticles markedly enhance the efficacy of radiotherapy against both irradiated and distal tumors in different tumor models via collectively promoting tumor-infiltrating CD8+ T-cell stemness and the activation of innate immunity. The radiosensitization effect of CS-Mn microparticles can be further augmented by concurrently applying anti-programmed cell death protein 1 (anti-PD-1) immunotherapy. This work highlights an ingenious strategy to prepare Trojan horse-like DNA-capturing microparticles as cGAS-STING-activating radiosensitizers for effective radioimmunotherapy.

Radiation-induced lymphopenia (RIL) has been shown to adversely affect the prognosis of cancer patients undergoing radiotherapy (RT). This model-based meta-analysis investigated the prognostic significance of lymphocyte counts both early and late after RT and examined the dose‒response relationship between post-RT lymphocyte levels and patient survival.

A literature search of published articles on the effect of RIL on cancer prognosis was conducted using the PubMed and Cochrane databases. A survival model was developed, incorporating absolute lymphocyte count (ALC) thresholds during (1 month after RT initiation, nadir) and 6 months after RT (recovery) as covariates to estimate progression-free survival (PFS) and overall survival (OS). This survival model, with the lymphocyte count cutoff as a covariate, was then used to simulate the benefit of increased PFS and OS in populations without lymphopenia or severe lymphopenia compared to the total population.

A total of 35 studies met the inclusion criteria for survival analysis. Our survival model revealed an increase in survival in the subgroup without lymphopenia compared to the total population. The subgroup without lymphopenia 1 month after RT initiation showed a 10.28 % and 3.92 % increase in 24-month PFS and OS, respectively. The subgroup without lymphopenia at 6 months showed a 5.82 % and 2.78 % increase in 24-month PFS and OS, respectively.

This study highlights the critical role of lymphocyte nadir and recovery following RT in patient prognosis and strengthens the evidence for a causal relationship between RIL and patient outcomes. Expanding the dataset and including randomized controlled trials would provide a more comprehensive understanding of monitoring or knowledge of ALC profiles following RT.

This study explored the safety and efficacy of combining radiotherapy with sintilimab in non-small cell lung cancer (NSCLC) patients who have progressed after first or second-line therapy.

In this multicenter, single-arm trial, patients with NSCLC who had progressed after first or second-line therapy were enrolled. Participants received hypofractionated stereotactic body radiotherapy (SBRT) (requiring a single-site biological dose of more than 30 Gy or planned to reach 30 Gy) followed by sintilimab every 3 weeks until disease progression or unacceptable toxicity occurred.

From March 1, 2019, to July 27, 2023, 14 patients were enrolled across two centers. The cohort included 64.3% males and 35.7% females, with a median age of 67 years (range 57-73 years). All participants completed radiation therapy and received at least one cycle of sintilimab. The overall response rate (ORR) was 21.4% (3/14) and the disease control rate (DCR) was 71.4% (10/14). The absent radiation response (ARR) was 14.3% (2/14). The median PFS was 4.17 months (95% CI: 1.15-8.69 months), with a 6-month PFS rate of 42.9%. The median OS was 16.17 months (95% CI: 11.69-20.64 months). Overall, 10 patients (71.4%) experienced at least one treatment-emergent adverse event (TEAE). Grade 3 adverse events included one case each of immune-related myocarditis, thrombocytopenia, and checkpoint inhibitor pneumonitis (CIP). Four patients (28.6%) had immune-related adverse events (irAEs) including skin rash and pruritus (2/14, grade 1), immune-related myocarditis (1/14, grade 3), and CIP (1/14, grade 3).

Radiotherapy combined with sintilimab for NSCLC patients who progressed after first-or second-line therapy showed promising efficacy outcomes.

Metal-protein hybrid materials represent a novel class of functional materials that exhibit exceptional physicochemical properties and tunable structures, rendering them remarkable applications in diverse fields, including materials engineering, biocatalysis, biosensing, and biomedicine. The design and development of multifunctional and biocompatible metal-protein hybrid materials have been the subject of extensive research and a key aspiration for practical applications in clinical settings. This review provides a comprehensive analysis of the design strategies, intrinsic properties, and biomedical applications of these hybrid materials, with a specific emphasis on their potential in cancer therapy, drug and vaccine delivery, antibacterial treatments, and tissue regeneration. Through rational design, stable metal-protein hybrid materials can be synthesized using straightforward methods, enabling them with therapeutic, delivery, immunomodulatory, and other desired functionalities. Finally, the review outlines the existing limitations and challenges associated with metal-protein hybrid materials and evaluates their potential for clinical translation, providing insights into their practical implementation within biomedical applications.

In situ vaccine (ISV) can activate the anti-tumor immune system by inducing immunogenic cell death (ICD) at the tumor site. However, the development of tumor ISV still faces challenges due to insufficient tumor antigens released by tumor cells and the existence of tumor immunosuppressive microenvironment (TIME). Targeting the STING pathway has been reported to enhance the adjuvant effects of in situ tumor vaccines by initiating innate immunity. Based on this, we developed a potent in situ cancer vaccine, MBMA-RGD ISV, which simultaneously induces ICD and activates the STING pathway to achieve sustained anti-tumor immunity. Specifically, a water-soluble prodrug Mit-ALA was synthesized from the chemotherapeutic agent mitoxantrone (Mit) and the photosensitizer precursor 5-aminolevulinic acid (5-ALA) by pH-responsive ester bonds, which was then loaded into pre-synthesized BSA-MnO2 nanoparticles and functionalized with the targeting Arg-Gly-Asp (RGD) peptide to obtain MBMA-RGD ISV. This ISV actively targets tumor cells by binding integrin receptors and then gradually releases antitumor components in response to tumor microenvironment (TME). The released 5-ALA is metabolized in mitochondria to produce photosensitizer PpIX. Under laser irradiation, the photodynamic property of PpIX coupled with the photothermal effect of Mit synergistically induced ICD, resulting in the release of tumor antigens and evoking adaptive immunity. Meanwhile, released Mn2+ and Mit synergistically activate the STING pathway by inducing DNA damage, further enhancing antitumor immunity. Moreover, large amounts of oxygen released by MnO2 relieved the hypoxia microenvironment, thus sensitizing photodynamic therapy and improving the immunosuppressive state of TME. Therefore, MBMA-RGD ISV efficiently activates systemic antitumor immunity in vitro and in vivo, providing new strategies and ideas for the development of tumor ISV. STATEMENT OF SIGNIFICANCE: Using a biocompatible BSA-MnO2 nanoplatform, we developed a dual-prodrug tumor in situ vaccine (ISV) with tumor microenvironment-responsive action for synergistic cancer immunotherapy. Once internalized by tumor cells, the MBMA-RGD ISV responded to intracellular H+, H2O2, and GSH, releasing its therapeutic "cargo." Under laser irradiation, the combined effects of photodynamic therapy (PDT) and photothermal therapy (PTT) induced immunogenic cell death (ICD), effectively recruiting and stimulating dendritic cells (DCs). Concurrently, STING pathway activation, triggered by DNA damage, enhanced DC maturation. Moreover, the MnO2 component alleviated hypoxia within the tumor microenvironment by releasing significant amounts of oxygen, which facilitated the repolarization of macrophages from the M2 phenotype to the M1 phenotype. Therefore, MBMA-RGD ISV demonstrated potent suppression of tumor metastasis and recurrence without notable side effects in mouse tumor models.

T cells have a critical role in mediating antitumour immunity. The success of immune checkpoint inhibitors (ICIs) for cancer treatment highlights how enhancing endogenous T cell responses can mediate tumour regression. However, mortality remains high for many cancers, especially in the metastatic setting. Based on advances in the genetic characterization of tumours and identification of tumour-specific antigens, individualized therapeutic cancer vaccines targeting mutated tumour antigens (neoantigens) are being developed to generate tumour-specific T cells for improved therapeutic responses. Early clinical trials using individualized neoantigen vaccines for patients with advanced disease had limited clinical efficacy despite demonstrated induction of T cell responses. Therefore, enhancing T cell activity by improving the magnitude, quality and breadth of T cell responses following vaccination is one current goal for improving outcome against metastatic tumours. Another major consideration is how T cells can be further optimized to function within the tumour microenvironment (TME). In this Perspective, we focus on neoantigen vaccines and propose a new approach, termed Vax-Innate, in which vaccination through intravenous delivery or in combination with tumour-targeting immune modulators may improve antitumour efficacy by simultaneously increasing the magnitude, quality and breadth of T cells while transforming the TME into a largely immunostimulatory environment for T cells.

Extensive-stage small cell lung cancer (ES-SCLC) remains a challenging malignancy with a poor prognosis. The integration of immunochemotherapy and combined consolidative thoracic radiotherapy (cTRT) presents a potential paradigm shift in treatment. This study aims to evaluate the real-world efficacy and safety of this approach.

In a single-center retrospective study conducted at Shandong Cancer Hospital, electronic medical records of 828 ES-SCLC patients treated between January 1, 2022, and December 31, 2023, were reviewed. Patients were divided into three cohorts based on treatment strategies: chemoradiotherapy (cohort A), immunochemotherapy without/with cTRT (cohort B/C). Propensity score matching was utilized to adjust for baseline differences. The primary outcomes were real-world progression-free survival (rwPFS) and overall survival (OS). Secondary outcomes included the incidence and severity of specific interested adverse events (AEs).

Of the 374 patients analyzed, cohort C showed significant improvements in rwPFS and OS compared to cohort A. The median rwPFS in cohort C (10.9 months) was longer than that of cohorts A (7.6 months) and B (8.0 months). The 12-month rwPFS rate was highest in cohort C (41%), compared to cohorts A (19%) and B (34%). The incidence of grade 3 or higher AEs was comparable across cohorts, with myelosuppression being the most common. However, the incidence of grade 3 or higher pneumonitis was notably higher in cohorts B and C, aligning with previous reports.

The combination of cTRT with immunochemotherapy for ES-SCLC showed improved rwPFS and OS, indicating potential benefit in this population. The overall safety profile remained manageable. These findings highlight the need for further prospective studies to confirm the optimal integration of cTRT in ES-SCLC treatment strategies.

Blocking the C-X-C motif chemokine ligand-12/C-X-C motif chemokine receptor-4 (CXCL12/CXCR4) signal offers the potential to induce immunogenic cell death (ICD) and enhance immunotherapy of glioblastoma (GBM). However, traditional intracellular targeted delivery strategies and adenosine-mediated tumor immunosuppression limit its therapeutic efficacy. Herein, we present an acidity-triggered self-assembly nanoplatform based on bioorthogonal reaction to potentiate GBM immunotherapy through dual regulation of metabolism and immune pathways. AMD3100 (CXCR4 antagonist) and CPI-444 (adenosine 2A receptor inhibitor) were formulated into micelles, denoted as AMD@iNPDBCO and CPI@iNPN3, respectively. Upon administration, the pH-sensitive poly(2-azepane ethyl methacrylate) group of AMD@iNPDBCO responds to the acidic tumor microenvironment, exposing the DBCO moiety, resulting in highly efficient bioorthogonal reaction with azide group on CPI@iNPN3 to form large-sized aggregates, ensuring extracellular drug release. The combination of AMD3100 and CPI-444 contributes to ICD induction, dendritic cell maturation, and immunosuppressive milieu alleviation by reducing tumor-associated macrophages, myeloid-derived suppressor cells, and regulatory T cells, leading to a robust antitumor response, thereby significantly prolonging survival in orthotopic GBM-bearing mice. Furthermore, the nanoplatform remarkably amplifies immuno-radiotherapy by potently evoking cytotoxic CD8+ T cell priming, and synergized with immune checkpoint blockade by delaying CD8+ T cell exhaustion. Our work highlights the potential of the in situ assembly nanoplatform tailored for delivery of extracellular-targeted therapeutic agents for boosting GBM immunotherapy.

Over the past decade, circular RNAs (circRNAs) have gained recognition as a novel class of genetic molecules, many of which are implicated in cancer pathogenesis via different mechanisms, including drug resistance, immune escape, and radio-resistance. ExosomalcircRNAs, in particular, facilitatecommunication between tumour cells and micro-environmental cells, including immune cells, fibroblasts, and other components. Notably, micro-environmental cells can reportedly influence tumour progression and treatment resistance by releasing exosomalcircRNAs. circRNAs often exhibit tissue- and cancer-specific expression patterns, and growing evidence highlights their potential clinical relevance and utility. These molecules show strong promise as potential biomarkers and therapeutic targets for cancer diagnosis and treatment. Therefore, this review aimed to briefly discuss the latest findings on the roles and resistance mechanisms of key circRNAs in the treatment of various malignancies, including lung, breast, liver, colorectal, and gastric cancers, as well as haematological malignancies and neuroblastoma.This review will contribute to the identification of new circRNA biomarkers for the early diagnosis as well as therapeutic targets for the treatment of cancer.

Gastrointestinal (GI) cancers account for more than one-third of cancer-related mortality, and the prognosis for late-stage patients remains poor. Immunotherapy has been proven to extend the survival of patients at advanced stages; however, challenges persist in patient selection and overcoming drug resistance. Tumor-infiltrating lymphocytes (TILs) and tertiary lymphoid structures (TLS) in the tumor microenvironment (TME) have been found to be associated with anti-tumor immune responses. 'Hot tumors' with high levels of infiltration tend to respond better to immune checkpoint inhibitor (ICI) therapy, making them potential biomarkers for ICI treatment.

To explore potential biomarkers for predicting immunotherapy response and prognosis in GI cancers, we downloaded the gene expression profiles of seven GI cancers from The Cancer Genome Atlas (TCGA) database and characterized their TME, classifying the samples into hot/cold tumor subgroups. Furthermore, we developed a computational framework to construct cancer-specific hot tumor classification models with only a few genes. External independent datasets and qPCR experiments were used to verify the performance of our few-gene models.

We constructed cancer-specific few-gene models to identify hot tumors for GI cancers with only two to nine genes. The results showed that B cells are important for hot tumor determination, and the identified hot tumors are significantly associated with TLS. They not only overexpress TLS marker genes but are also associated with the presence of TLS in whole-slide images. Further, a two-gene qPCR model was developed to effectively distinguish between hot and cold tumor subgroups in cholangiocarcinoma, providing an opportunity for stratifying patients with hot tumors in clinical settings.

In conclusion, our established few-gene models, which can be easily integrated into clinical practice, can distinguish hot and cold tumor subgroups, and may serve as potential biomarkers for predicting ICI response.

The magnitude of Type I interferon (IFN) mediated innate immune response within the tumor microenvironment (TME) critically influences the effectiveness of radiotherapy. Unfortunately, due to a myriad of resistance mechanisms, the double-stranded DNA (dsDNA) signals produced by tumor cells postradiotherapy often induce a diminished response from immune cells. Through chemical screening targeting deubiquitinating enzymes, we identified USP1 (Ubiquitin Specific Peptidase 1) inhibitor as an enhancer of post-radiotherapy dsDNA responses. Mechanistically, within the context of immune-stimulatory cells in TME, USP1 serves as a suppressor in the stress-mediated stages of the cGAS (Cyclic GMP-AMP synthase) -STING (Stimulator of interferon genes protein) signaling pathway, specifically affecting the trafficking of STING from endoplasmic reticulum to Golgi apparatus. It is elucidated that SAR1A (Secretion associated Ras related GTPase 1A) requires K27-linked oligo-ubiquitination to assemble the STING-COP-II (Coat protein II) transport complex for STING trafficking. USP1 counteracts this activation by removing SAR1A ubiquitination, thereby blocking STING trafficking and activation. Consequently, pharmacological USP1 inhibition using ML323 sustains SAR1A ubiquitination and COP-II complex formation, significantly enhancing STING trafficking and subsequent Type I IFN production. This intervention substantially amplifies radiotherapy-induced immune activation in the TME, providing a strategic approach to overcome therapeutic resistance and synergize radiotherapy with immunotherapies.

Immunogenic cell death (ICD) enhances anti-tumor immunity by releasing tumor-associated antigens and activating the anti-tumor immune system response. However, its potential remains understudied in combination therapies. Here, we develop a mathematical model to quantify the role of ICD in optimizing the efficacy of combined radiotherapy (RT) and macrophage-based immunotherapy. Using preclinical murine data targeting the SIRP α -CD47 checkpoint, we show that RT alone induces minimal ICD, whereas disrupting the SIRP α -CD47 axis significantly enhances both phagocytosis and systemic immune activation. Our model predicts an optimal RT dose (6-8 Gy) for maximizing ICD, a dose-dependent abscopal effect, and a hierarchy of treatment efficacy, with SIRP α -knockout macrophages exhibiting the strongest tumoricidal activity. These findings provide a quantitative framework for designing more effective combination therapies, leveraging ICD to enhance immune checkpoint inhibition and radiotherapy synergy.

The activation of the cGAS-STING pathway occurs when tumor cell DNA is damaged by ionizing radiation. Once triggered, this pathway reshapes the tumor immune microenvironment by promoting the maturation, activation, polarization, and immune-killing capacity of immune cells, as well as by inducing the release of interferons and the expression of immune-related genes. In addition, the gut microbiota and various mechanisms of programmed cell death interact with the cGAS-STING pathway, further influencing its function in remodeling the immune microenvironment after radiotherapy. Therefore, investigating the mechanisms of the cGAS-STING pathway in reshaping the tumor immune microenvironment post-radiotherapy can not only optimize the efficacy of combined radiotherapy and immunotherapy but also provide new research directions and potential targets for cancer treatment.

Combination of immunotherapy and photothermal therapy (PTT) provides a promising therapeutic performance for tumors. However, it still faces negative feedback from suppressive factors such as adenosine. Herein, we developed a new nanodrug that can combine adenosine blockade and ferroptosis to promote the photoimmunotherapy of triple negative breast cancer (TNBC). The nanodrug, named CuS-PEG@Apt, was constructed via the modification of copper sulfide (CuS) nanoparticles with adenosine aptamer and PEG. CuS-PEG@Apt could be effectively enriched in the tumor site and locally generate a strong photothermal effect, directly ablating tumors and inducing immunogenic death (ICD). On the other hand, the aptamers could block the adenosine pathway to inhibit the immune suppression by adenosine, which further promoted the anti-tumor immunity. Moreover, the CuS nanoparticles could consume GSH and inhibit GPX4 to cause the ferroptosis of tumor cells. Collectively, CuS-PEG@Apt achieved potent efficacy of tumor suppression via the combination of PTT, immune activation and ferroptosis, representing an appealing platform for TNBC treatment.

Microsatellite stable (MSS) colorectal cancer with liver metastases (CLRM) responds poorly to immunotherapy, and various approaches to break immune tolerance have been tried. Radiotherapy in combination with immune checkpoint inhibitors is one of promising therapies, and the choice of radiotherapy and immunotherapy modalities is also a hot issue.

Here, we report on a Phase I trial treating nine patients with MSS CLRM using a combination of high and low dose radiotherapy and immune checkpoint inhibitors (ICIs).

The primary endpoint of the trial was the safety and tolerability of this combination treatment modality. Secondary endpoints included the objective response rate (ORR), progression-free survival (PFS) and overall survival (OS). The study results showed that at three dose levels-single doses of 6Gy (n=3), 8Gy (n=3), and 10Gy (n=3)-the most common treatment-related adverse events (TRAEs) were nausea, vomiting, fatigue, and abnormal liver function. At the first condition assessment, four patients were observed to have stable disease (SD) and one patient achieved partial response (PR). In exploratory endpoint analyses, tissue biopsies and paired hematologic samples from patients showed M2 macrophage reduction. Plasma cytokines IL-10, IL-17, and INF-α increased after treatment with both drugs.

In summary, this is the first clinical trial demonstrating the safety and immunogenic activity of combined high and low dose radiotherapy with ICIs in MSS colorectal cancer liver metastases (CRLMs). The combination therapy stimulated the immune response and altered the tumour microenvironment, warranting further exploration in the future.

This multicenter Phase II clinical study assessed the efficacy and safety of hypofractionated radiotherapy (HFRT) in combination with a PD-1 inhibitor, granulocyte macrophage-colony stimulating factor (GM-CSF), and thymosin-α1 in patients with heavily treated metastatic solid tumors.

Patients were enrolled between September 2022 and May 2024. HFRT was administered to targeted tumors, and GM-CSF was administered for 14 days from day 1 of radiotherapy. Thymosin-α1 was injected concurrently twice weekly until disease progression. Immunotherapy with camrelizumab was started following HFRT and repeated every 3 weeks. GM-CSF was administered daily for 7 days before each cycle of immunotherapy.

By June 15, 2024, there were 37 study participants. The median follow-up duration was 5.97 months (range 0.40-20.9). Median progression-free survival was 3.5 months (95% confidence interval 2.73-4.23) in the intention-to-treat population. The objective response rate was 23.08%, and the disease control rate was 65.38%. Overall survival data are not yet mature. Abscopal effects were observed in 6 patients (23.08%); four of whom achieved a partial response. Patients who achieved a partial response were significantly more likely to have an abscopal effect( P = 0.025). The group with a lower baseline neutrophil-lymphocyte ratio had a significantly lower risks of distant metastasis and death( P = 0.024). Seventeen adverse reactions were reported, including six grade 3 or 4 adverse events. There were no grade 5 adverse events.

In conclusion, the trends in efficacy observed in our study are promising; however, well-designed protocols are essential to validate these findings.

This report details the reactivation of immune checkpoint inhibitor (ICI)-related autoimmune hepatitis triggered by stereotactic body radiation therapy (SBRT) in a 55-year-old male with hilar cholangiocellular carcinoma. Initially diagnosed in December 2021, the patient underwent successful resection and subsequent adjuvant therapy. Despite stable disease following chemotherapy augmented with durvalumab, he developed grade 3 acute hepatitis after seven cycles of durvalumab. Following a brief prednisolone regimen and normalization of liver tests, SBRT targeting para-aortic lymph nodes was initiated. Remarkably, severe hepatitis reoccurred 7 days after starting SBRT, 88 days following the last durvalumab infusion, necessitating resumed and escalated prednisolone treatment. Another course of SBRT for a newly diagnosed metastatic liver lesion was administered in September 2023, with ongoing prednisolone adjustment. By February 2024, liver tests normalized, but subsequent radiological assessments indicated tumor progression, leading to the reintroduction of chemotherapy. This case underscores the potential of SBRT for activating severe immune-mediated hepatotoxicity in patients treated with ICIs, highlighting the need for careful monitoring and management of such patients. Further, this report highlights the possible survival benefit of the strategic application of SBRT in addition to systematic treatment in recurrent and metastatic cholangiocellular carcinoma.

Chimeric antigen receptor (CAR) T-cell therapy has achieved potent antitumor efficacy in hematological malignancies; however, because of limitations in CAR T-cell recruitment, infiltration, activation, and functional persistence in the tumor, its efficacy in solid tumors has been suboptimal. To overcome these challenges, combinational strategies that include chemotherapy, radiation therapy, or immune checkpoint inhibitor agent therapy with CAR T-cell therapy are being investigated. The established functional characteristics of the abovementioned therapies provide a rationale for the use of a combinational approach with CAR T cells. Chemotherapy reshapes the peritumoral stroma, decreases the immunosuppressive cell population, and promotes a proinflammatory milieu, all of which allow for increased recruitment, infiltration, and accumulation of CAR T cells. Radiation therapy promotes a chemokine gradient, which augments tumor infiltration by CAR T cells and further increases expression of tumor-associated antigens, allowing for increased activation of CAR T cells. Immune checkpoint inhibitor agent therapy inactivates T-cell exhaustion pathways-most notably, the PD1/PDL1 pathway-thereby improving the functional persistence of CAR T cells and promoting endogenous immunity. In this review, we discuss the requisites and rationales for combinational therapy, and we review 25 ongoing phase I and II clinical trials, of which 4 use chemotherapy, 3 use radiation therapy, 11 use immunotherapy, and 7 use another agent. While safety, efficacy, and improved outcomes are the primary goals of these ongoing studies, the knowledge gained from them will help pave the way for subsequent studies focused on optimizing combinational regimens and identifying predictive biomarkers.

Hepatocellular carcinoma (HCC) is a complex disease with advanced presentation that significantly affects survival rates. Therefore, novel therapeutic strategies are needed. In this study, we investigate the tumor microenvironment (TME) in HCC by analyzing 13 HCC samples at single cell level. We identified key cell populations, including CD8 + T cells, Tregs, M1/M2 macrophages, and CD4 + memory T cells, and explored their roles and interactions. Our research revealed an early enrichment of CD8 + T cells, which could potentially lead to their exhaustion and facilitate tumor progression. We also investigated the impact of percutaneous radiofrequency ablation (RFA) on the immune microenvironment. Using a dual tumor mouse model, we demonstrated that RFA induces necrosis, enhancing antigen presentation and altering immune responses. Our results indicate that RFA increases PD-L1 expression in residual liver tissue, suggesting potential immune escape mechanisms. Furthermore, the combination of RFA and anti-PD-L1 therapy in the mouse model resulted in significant improvements in immune modulation. This included increased CD8 + T cell efficacy and decreased Treg infiltration. This combination shows promise as an approach to counteract HCC progression by altering the immune landscape. This study highlights the critical interaction within the TME of HCC and suggests the possibility of improving patient outcomes by targeting immune evasion mechanisms through combined therapeutic strategies.

Hafnium (Hf)-based nanoscale metal-organic layers (MOLs) enhance radiotherapeutic effects of tissue-penetrating X-rays via a unique radiotherapy-radiodynamic therapy (RT-RDT) process through efficient generation of hydroxy radical (RT) and singlet oxygen (RDT). However, their radiotherapeutic efficacy is limited by hypoxia in deep-seated tumors and short half-lives of reactive oxygen species (ROS). Herein the conjugation of a nitric oxide (NO) donor, S-nitroso-N-acetyl-DL-penicillamine (SNAP), to the Hf12 secondary building units (SBUs) of Hf-5,5'-di-p-benzoatoporphyrin MOL is reported to afford SNAP/MOL for enhanced cancer radiotherapy. Under X-ray irradiation, SNAP/MOL efficiently generates superoxide anion (O2 -.) and releases nitric oxide (NO) in a spatio-temporally synchronized fashion. The released NO rapidly reacts with O2 -. to form long-lived and highly cytotoxic peroxynitrite which diffuses freely to the cell nucleus and efficiently causes DNA double-strand breaks. Meanwhile, the sustained release of NO from SNAP/MOL in the tumor microenvironment relieves tumor hypoxia to reduce radioresistance of tumor cells. Consequently, SNAP/MOL plus low-dose X-ray irradiation efficiently inhibits tumor growth and reduces metastasis in colorectal and triple-negative breast cancer models.

Cancer immunotherapies rely on CD8+ cytolytic T lymphocytes (CTLs) in recognition and eradication of tumor cells via antigens presented on major histocompatibility complex class I (MHC-I) molecules. However, we observe MHC-I deficiency in human and murine urologic tumors, posing daunting challenges for successful immunotherapy. We herein report an unprecedented nanosonosensitizer of one-dimensional bamboo-like multisegmented manganese dioxide@manganese-bismuth vanadate (BMMBV) to boost multiple branches of immune responses targeting MHC-I-deficient tumors. BMMBV markedly augments sonodynamic activity contributed by manganese heteroatoms in the lattice of bismuth vanadate with narrowing bandgaps. Under sonoirradiation, BMMBV enhances tumor antigen spreading and emission of adjuvant signals, which potentiate dendritic cell maturation, thereby eliciting high aptitude of CTLs. This therapy substantially up-regulates MHC expression on tumor cells, which are reversely sensitive to CTLs. Alongside, extensive innate immune cells complement the cytolytic activity of CTLs for eliminating mouse urologic tumors. This study offers a reinforced strategy against antigen-loss immune-evasive tumor.

Cancer immunotherapy is a relatively new approach to cancer treatment. Peptides that target specific pathways and cells involved in immunomodulation can potentially improve the efficacy of cancer therapy. Recently, we reported iPD-L1 as a novel inhibitor peptide that specifically targets the cancer cell ligand PD-L1 (programmed death ligand 1). PD-L1 is responsible for inhibiting the immune checkpoint protein PD-1 expressed by regulatory T cells. On the other hand, anti-PD-L1 immunotherapy in combination with external beam radiotherapy has shown improved outcomes in the treatment of breast and lung cancer. The aim of this research was to prepare 177Lu-labeled iPD-L1 and to preclinically evaluate its radiotherapeutic potential and role as a tumor immunomodulator by measuring macrophage activation, IL-10, TGFβ, and PD-L1 expression in 4T1 triple-negative breast cancer cells and murine 4T1 tumors after treatment with 177Lu-iPD-L1.

The iPD-L1 ligand, characterized by UPLC mass, UV-Vis, and FT-IR spectroscopies, showed a chemical purity of 99%. The 177Lu-iPD-L1 radiochemical purity was 98.9 ± 1.1%. In vitro and in vivo studies demonstrated radiotracer stability in human serum (> 97% after 24 h evaluated by radio-HPLC), adequate affinity by the PDL1 protein (IC50 = 4.21 nM), and specific detection for PD-L1 assessed in 4T1, HCT116, and AR42J cancer cells, in which PD-L1 expression was verified by immunofluorescence and Western Blot assays. After treatment with 177Lu-iPD-L1 (0.4 Bq/cell), flow cytometry results showed a significant decrease in cell viability of 4T1 cells (dead 56.2%) compared to 177LuCl3 (dead 34.2%) and untreated cells (dead 9.4%). With high tumor uptake (6.97 ± 1.04%ID) and hepatobiliary and renal clearance, lutetium-177-labeled iPD-L1 delivered a tumor dose of 27 Gy/37 MBq and less than 0.36 Gy/37 MBq to non-source organs. PD-L1 positive tumors showed a significant increase in activated macrophages, PD-L1, IL-10, and TGFβ expression levels after 177Lu-iPD-L1 treatment as evaluated by ELISA assay and immunohistochemistry.

Therefore, this study warrants further dosimetric and clinical studies to determine the immunomodulatory effect and therapeutic efficacy of 177Lu-iPD-L1 in treating PD-L1-positive tumors in combination with anti-PD-1/PD-L1 immunotherapy protocols.

Radiotherapy may enhance antitumor immune responses by several mechanisms, including induction of immunogenic cell death. We performed a phase 2 study of pembrolizumab with re-irradiation in patients with recurrent glioblastoma.

Sixty patients with recurrent glioblastoma received pembrolizumab with re-irradiation alone (cohort A, bevacizumab-naïve; n = 30) or with bevacizumab continuation (cohort B, n = 30). Dual primary endpoints, including the overall response rate and overall survival (OS) at either 12 (OS-12; cohort A) or 6 months (OS-6; cohort B), were assessed per cohort relative to historic benchmarks. Paired paraffin-embedded formalin-fixed tumor samples were assessed for immunologic biomarkers by IHC using digital quantification and co-detection-by-indexing (CODEX).

Study therapy was well tolerated, with most toxicities being grade ≤3. For cohort B, the primary endpoint of OS-6 was achieved (57%); however, survival was not improved for cohort A patients. The overall response rate was 3.3% and 6.7% for cohorts A and B, respectively. CODEX analysis of paired tumor samples from five patients revealed an increase of activated T cells in the tumor microenvironment after study therapy.

Compared with historic controls, re-irradiation plus pembrolizumab seemed to improve survival among bevacizumab-refractory patients but not among bevacizumab-naïve patients. CODEX revealed evidence of intratumoral infiltration of activated immune effector cells. A randomized, properly controlled trial of PD-1 blockade plus re-irradiation is warranted to further evaluate this regimen for bevacizumab-refractory patients, but alternative approaches are needed for bevacizumab-naïve patients.