Evaluation of a Combinatorial Immunotherapy Regimen That Can Cure Mice Bearing MYCN-Driven High-Risk Neuroblastoma That Resists Current Clinical Therapy

Background: Incorporating GD2-targeting monoclonal antibody into post-consolidation maintenance therapy has improved survival for children with high-risk neuroblastoma. However, ~50% of patients do not respond to, or relapse following, initial treatment. Here, we evaluated additional anti-GD2-based immunotherapy to better treat high-risk neuroblastoma in mice to develop a regimen for patients with therapy-resistant neuroblastoma. Methods: We determined the components of a combined regimen needed to cure mice of established MYCN-amplified, GD2-expressing, murine 9464D-GD2 neuroblastomas. Results: First, we demonstrate that 9464D-GD2 is nonresponsive to a preferred salvage regimen: anti-GD2 with temozolomide and irinotecan. Second, we have previously shown that adding agonist anti-CD40 mAb and CpG to a regimen of radiotherapy, anti-GD2/IL2 immunocytokine and anti-CTLA-4, cured a substantial fraction of mice bearing small 9464D-GD2 tumors; here, we further characterize this regimen by showing that radiotherapy and hu14.18-IL2 are necessary components, while anti-CTLA-4, anti-CD40, or CpG can individually be removed, and CpG and anti-CTLA-4 can be removed together, while maintaining efficacy. Conclusions: We have developed and characterized a regimen that can cure mice of a high-risk neuroblastoma that is refractory to the current clinical regimen for relapsed/refractory disease. Ongoing preclinical work is directed towards ways to potentially translate these findings to a regimen appropriate for clinical testing.

A neutrophil response linked to tumor control in immunotherapy

Neutrophils accumulate in solid tumors, and their abundance correlates with poor prognosis. Neutrophils are not homogeneous, however, and could play different roles in cancer therapy. Here, we investigate the role of neutrophils in immunotherapy, leading to tumor control. We show that successful therapies acutely expanded tumor neutrophil numbers. This expansion could be attributed to a Sellhi state rather than to other neutrophils that accelerate tumor progression. Therapy-elicited neutrophils acquired an interferon gene signature, also seen in human patients, and appeared essential for successful therapy, as loss of the interferon-responsive transcription factor IRF1 in neutrophils led to failure of immunotherapy. The neutrophil response depended on key components of anti-tumor immunity, including BATF3-dependent DCs, IL-12, and IFNγ. In addition, we found that a therapy-elicited systemic neutrophil response positively correlated with disease outcome in lung cancer patients. Thus, we establish a crucial role of a neutrophil state in mediating effective cancer therapy.

The immunotoxicity, but not anti-tumor efficacy, of anti-CD40 and anti-CD137 immunotherapies is dependent on the gut microbiota

Immune agonist antibodies (IAAs) are promising immunotherapies that target co-stimulatory receptors to induce potent anti-tumor immune responses, particularly when combined with checkpoint inhibitors. Unfortunately, their clinical translation is hampered by serious dose-limiting, immune-mediated toxicities, including high-grade and sometimes fatal liver damage, cytokine release syndrome (CRS), and colitis. We show that the immunotoxicity, induced by the IAAs anti-CD40 and anti-CD137, is dependent on the gut microbiota. Germ-free or antibiotic-treated mice have significantly reduced colitis, CRS, and liver damage following IAA treatment compared with conventional mice or germ-free mice recolonized via fecal microbiota transplant. MyD88 signaling is required for IAA-induced CRS and for anti-CD137-induced, but not anti-CD40-induced, liver damage. Importantly, antibiotic treatment does not impair IAA anti-tumor efficacy, alone or in combination with anti-PD1. Our results suggest that microbiota-targeted therapies could overcome the toxicity induced by IAAs without impairing their anti-tumor activity.

Conventional type I dendritic cells maintain a reservoir of proliferative tumor-antigen specific TCF-1+ CD8+ T cells in tumor-draining lymph nodes

In tumors, a subset of CD8+ T cells expressing the transcription factor TCF-1 drives the response to immune checkpoint blockade. We examined the mechanisms that maintain these cells in an autochthonous model of lung adenocarcinoma. Longitudinal sampling and single-cell sequencing of tumor-antigen specific TCF-1+ CD8+ T cells revealed that while intratumoral TCF-1+ CD8+ T cells acquired dysfunctional features and decreased in number as tumors progressed, TCF-1+ CD8+ T cell frequency in the tumor draining LN (dLN) remained stable. Two discrete intratumoral TCF-1+ CD8+ T cell subsets developed over time-a proliferative SlamF6+ subset and a non-cycling SlamF6- subset. Blocking dLN egress decreased the frequency of intratumoral SlamF6+ TCF-1+ CD8+ T cells. Conventional type I dendritic cell (cDC1) in dLN decreased in number with tumor progression, and Flt3L+anti-CD40 treatment recovered SlamF6+ T cell frequencies and decreased tumor burden. Thus, cDC1s in tumor dLN maintain a reservoir of TCF-1+ CD8+ T cells and their decrease contributes to failed anti-tumor immunity.

Acute Hemolysis and Heme Suppress Anti-CD40 Antibody-Induced Necro-Inflammatory Liver Disease

Clearance of red blood cells and hemoproteins is a key metabolic function of macrophages during hemolytic disorders and following tissue injury. Through this archetypical phagocytic function, heme is detoxified and iron is recycled to support erythropoiesis. Reciprocal interaction of heme metabolism and inflammatory macrophage functions may modify disease outcomes in a broad range of clinical conditions. We hypothesized that acute hemolysis and heme induce acute anti-inflammatory signals in liver macrophages. Using a macrophage-driven model of sterile liver inflammation, we showed that phenylhydrazine (PHZ)-mediated acute erythrophagocytosis blocked the anti-CD40 antibody-induced pathway of macrophage activation. This process attenuated the inflammatory cytokine release syndrome and necrotizing hepatitis induced by anti-CD40 antibody treatment of mice. We further established that administration of heme-albumin complexes specifically delivered heme to liver macrophages and replicated the anti-inflammatory effect of hemolysis. The anti-inflammatory heme-signal was induced in macrophages by an increased intracellular concentration of the porphyrin independently of iron. Overall, our work suggests that induction of heme-signaling strongly suppresses inflammatory macrophage function, providing protection against sterile liver inflammation.

Mannan-BAM, TLR Ligands, Anti-CD40 Antibody (MBTA) Vaccine Immunotherapy: A Review of Current Evidence and Applications in Glioblastoma

The foundation of precision immunotherapy in oncology is rooted in computational biology and patient-derived sample sequencing to enrich for and target immunogenic epitopes. Discovery of these tumor-specific epitopes through tumor sequencing has revolutionized patient outcomes in many types of cancers that were previously untreatable. However, these therapeutic successes are far from universal, especially with cancers that carry high intratumoral heterogeneity such as glioblastoma (GBM). Herein, we present the technical aspects of Mannan-BAM, TLR Ligands, Anti-CD40 Antibody (MBTA) vaccine immunotherapy, an investigational therapeutic that potentially circumvents the need for in silico tumor-neoantigen enrichment. We then review the most promising GBM vaccination strategies to contextualize the MBTA vaccine. By reviewing current evidence using translational tumor models supporting MBTA vaccination, we evaluate the underlying principles that validate its clinical applicability. Finally, we showcase the translational potential of MBTA vaccination as a potential immunotherapy in GBM, along with established surgical and immunologic cancer treatment paradigms.

Safety, pharmacokinetics and pharmacodynamics of BI 655064 in phase 1 clinical trials in healthy Chinese and Japanese subjects

Aims

To evaluate the safety, pharmacokinetics and pharmacodynamics of BI 655064 in healthy Chinese and Japanese subjects after administration of single doses of 80‐240 mg and multiple dosing of 240 mg once weekly over 4 weeks.

Methods

Two phase 1, double‐blind, placebo‐controlled studies were conducted (single‐rising doses of BI 655064 in Chinese/Japanese male subjects [n = 12 per BI 655064 dose group] or repeated 240 mg BI 655064 in Chinese male subjects [n = 9]). Plasma samples were collected to investigate BI 655064 pharmacokinetics, pharmacodynamics (CD40 receptor occupancy [RO]) and immunogenicity, along with the safety and tolerability of BI 655064.

Results

BI 655064 showed good overall tolerability following single‐dose administration of 80‐240 mg and repeated administration of 240 mg BI 655064 over 4 weeks. More Chinese subjects reported adverse events compared with Japanese subjects following single‐dose administration (59.4% vs 3.1%). BI 655064 exhibited nonlinear, saturable kinetics, with higher doses resulting in slower apparent clearance (0.514‐0.713 mL min⁻¹), and disproportionately higher total exposure (AUC_0‐inf; 5610‐7780 μg·h mL⁻¹) and maximum plasma concentration (15 700‐21 300 ng mL⁻¹) with 240 mg BI 655064. Ninety percent inhibition of CD40 RO was achieved with doses ≥120 mg, and a direct relationship between BI 655064 plasma concentration and inhibition of CD40 RO was observed. Most subjects had a positive treatment‐emergent antidrug antibody response.

Conclusions

BI 655064 pharmacokinetic and safety profiles in East Asian male subjects were consistent with those observed in a Western population. No adjustments in the BI 655064 dosing recommendations are warranted for future clinical trials.

Characteristics and clinical trial results of agonistic anti-CD40 antibodies in the treatment of malignancies

Cluster of differentiation 40 (CD40) mediates many immune activities. Preclinical studies have shown that activation of CD40 can evoke massive antineoplastic effects in several tumour models in vivo, providing a rationale for using CD40 agonists in cancer immunotherapy. To date, several potential agonistic antibodies that target CD40 have been investigated in clinical trials. Early clinical trials have shown that the adverse events associated with agonists of CD40 thus far have been largely transient and clinically controllable, including storms of cytokine release, hepatotoxicity and thromboembolic events. An antitumour effect of targeting CD40 for monotherapy or combination therapy has been observed in some tumours. However, these antitumour effects have been moderate. The present review aimed to provide updated details of the clinical results of these agonists, and offer information to further investigate the strategies of combining CD40 activation with chemotherapy, radiotherapy, targeted therapy and immunomodulators. Furthermore, biomarkers should be identified for monitoring and predicting responses and informing resistance mechanisms.

Monocytes Acquire the Ability to Prime Tissue-Resident T Cells via IL-10-Mediated TGF-β Release

Using non-human primates (NHPs), mice, and human primary cells, we found a role for interleukin-10 (IL-10) in the upregulation of the tissue-resident memory T cell (T_RM) marker CD103. In NHPs, intravenous, but not subcutaneous, immunization with peptide antigen and an adjuvant combining an agonistic anti-CD40 antibody plus poly(IC:LC) induced high levels of CD103⁺ T_RMs in the lung, which correlated with early plasma IL-10 levels. Blocking IL-10 reduced CD103 expression on human T cells stimulated in vitro with the adjuvant combination as well as diminished CD103 on lung-resident T cells in vivo in mice. Monocyte-produced IL-10 induced the release of surface-bound transforming growth factor β (TGF-β), which in turn upregulated CD103 on T cells. Early TGF-β imprinted increased sensitivity to TGF-β restimulation, indicating an early commitment of the T cell lineage toward T_RMs during the priming stage of activation. IL-10-mediated TGF-β signaling may therefore have a critical role in the generation of T_RM following vaccination.

Single Radiotherapy Fraction with Local Anti-CD40 Therapy Generates Effective Abscopal Responses in Mouse Models of Cervical Cancer

Current treatment options for advanced cervical cancer are limited, especially for patients in poor-resource settings, with a 17% 5-year overall survival rate. Here, we report results in animal models of advanced cervical cancer, showing that anti-CD40 therapy can effectively boost the abscopal effect, whereby radiotherapy of a tumor at one site can engender therapeutically significant responses in tumors at distant untreated sites. In this study, two subcutaneous cervical cancer tumors representing one primary and one metastatic tumor were generated in each animal. Only the primary tumor was treated and the responses of both tumors were monitored. The study was repeated as a function of different treatment parameters, including radiotherapy dose and dosing schedule of immunoadjuvant anti-CD40. The results consistently suggest that one fraction dose of radiotherapy with a single dose of agonistic anti-CD40 can generate highly effective abscopal responses, with a significant increase in animal survival (p = 0.0004). Overall, 60% of the mice treated with this combination showed long term survival with complete tumor regression, where tumors of mice in other cohorts continued to grow. Moreover, re-challenged responders to the treatment developed vitiligo, suggesting developed immune memory for this cancer. The findings offer a potential new therapy approach, which could be further investigated and developed for the treatment of advanced cervical cancer, with major potential impact, especially in resource-poor settings.

A Novel Anti-CD40 Monoclonal Antibody, Iscalimab, for Control of Graves Hyperthyroidism-A Proof-of-Concept Trial

CONTEXT

The CD40-CD154 co-stimulatory pathway plays an important role in the pathogenesis of Graves disease (GD) by promoting autoreactive B-cell activation.

OBJECTIVE

Evaluate efficacy and safety of a human, blocking, nondepleting anti-CD40 monoclonal antibody, iscalimab, in hyperthyroid patients with GD.

DESIGN

Open-label, phase II proof-of-concept study.

SETTING

Multicenter.

PATIENTS

Fifteen with GD.

INTERVENTION

Patients received 5 doses of iscalimab at 10 mg/kg intravenously over 12 weeks.

MAIN OUTCOME MEASURES

Thyroid-related hormones and autoantibodies, plasma soluble CD40, free CD40 on B cells, soluble CXCL13, pharmacokinetics, and safety were assessed.

RESULTS

The iscalimab intervention resulted in complete CD40 engagement for up to 20 weeks. A clinical response and biochemical euthyroidism was observed in 7 of 15 (47%) patients. Free and total triiodothyronine and thyroxine normalized in 7 patients who did not receive any rescue medication with antithyroid drugs (ATD), and 2/15 (13.3%) showed normal thyrotropin. Six (40%) patients required ATD. Four of 7 responders relapsed after treatment completion. Serum concentrations of thyrotropin receptor autoantibodies (TSH-R-Ab) significantly declined in all patients (mean 15.3 IU/L vs 4.0 IU/L, 66% reduction; P < 0.001) and TSH-R-Ab levels normalized in 4 (27%). Thyroperoxidase and thyroglobulin autoantibodies significantly decreased in responders. Iscalimab rapidly reduced serum CXCL13 concentrations (P < 0.001). Twelve (80.0%) patients reported at least 1 adverse event (AE). All treatment-related AE were mild or moderate and resolved by end of the study.

CONCLUSION

Iscalimab was generally safe and clinically effective in a subgroup of hyperthyroid GD patients. The potential therapeutic benefit of iscalimab should be further tested.

Efficacy of cytokine-induced killer cells targeting CD40 and GITR

Since the publication of a novel protocol in 1991, cytokine-induced killer (CIK) cells have shown promising results in the treatment against neoplastic diseases. Despite ongoing preclinical and clinical studies, CIK cell treatment in the context of human monoclonal antibodies targeting tumor-necrosis factor receptors remains overlooked. The present study investigated whether a combination of CIK cells with human monoclonal antibody anti-CD40 and anti-Glucocorticoid-induced TNF-related protein (GITR) would lead to further cytotoxicity against tumor cells expressing CD40 and GITR ligand (L). Therefore, in vitro experiments with human lymphoma cell lines SU-DHL-4 and Daudi (both CD40 positive) and human breast adenocarcinoma MCF-7 (GITRL positive) were performed and the secretion of interferon (IFN)-γ was measured. Three interesting results emerged: i) a combination of CIK cells and anti-CD40 mAb is more effective than CIK cell treatment alone; ii) the use of anti-GITR mAb and CIK cells significantly enhanced the cytotoxicity of CIK cells against MCF-7 compared with single CIK cell treatment and iii) the combination of both antibodies and CIK cells abrogates the anti tumoral effect of CIK cells on all three cell lines. By performing an ELISA for IFN-γ measurement, a lower secretion was observed when anti-CD40 or anti-GITR mAb was added. This outcome indicates that further studies in vitro and in vivo may aid in understanding the synergistic molecular mechanisms of CIK cells, and anti-CD40 and anti-GITR mAb.

Safety, Pharmacokinetics, and Pharmacodynamics of Multiple Rising Doses of BI 655064, an Antagonistic Anti-CD40 Antibody, in Healthy Subjects: A Potential Novel Treatment for Autoimmune Diseases

BI 655064 is a humanized antagonistic anti-cluster of differentiation (CD) 40 monoclonal antibody that selectively blocks the CD40-CD40L interaction. The CD40-CD40L pathway is a promising treatment target for autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus, and lupus nephritis. The safety, tolerability, pharmacokinetics, and pharmacodynamics of repeated once-weekly BI 655064 subcutaneous dosing over 4 weeks were evaluated in a multiple-dose study in healthy subjects. Subjects (N = 40) were randomized 4:1 to four sequential BI 655064 dose groups (80, 120, 180, 240 mg) or to placebo. Safety and tolerability, plasma exposure, CD40 receptor occupancy, and CD40L-induced CD54 upregulation were assessed over 64 and 78 days for the 80- to 180-mg and 240-mg dose groups, respectively. BI 655064 exposure increased in a supraproportional manner, due to target-mediated drug clearance, for doses between 80 mg and 120 mg, but was near proportional for doses greater than 120 mg. Terminal half-life ranged between 6 and 8 days. Dose-dependent accumulation of BI 655064 supports the use of a loading dose in future clinical studies. Following 4 weeks of dosing, >90% CD40 receptor occupancy and inhibition of CD54 upregulation were observed at all dose levels, lasting for 17 days after the last dose. BI 655064 was generally well tolerated. There were no serious adverse events and the frequency and intensity of adverse events were similar for BI 655064 and placebo; no dose relationship or relevant signs of an acute immune reaction were observed. These findings support further investigation of BI 655064 as a potential treatment for autoimmune diseases.

Effective antitumor peptide vaccines can induce severe autoimmune pathology

Immunotherapy has shown a tremendous success in treating cancer. Unfortunately, this success is frequently associated with severe autoimmune pathology. In this study, we used the transgenic RIP-gp mouse model to assess the antitumor therapeutic benefit of peptide vaccination while evaluating the possible associated autoimmune pathology. We report that palmitoylated gp33-41 peptide and poly-IC adjuvant vaccine (BiVax) generated ∼ 5-10 % of antigen specific T cell responses in wild type and supposedly immune tolerant RIP-gp mice. Boosting with BiVax in combination with αCD40 antibody (TriVax) or BiVax in combination with IL-2/αIL-2 antibody complexes (IL2Cx) significantly increased the immune responses (∼30-50%). Interestingly, although both boosts were equally effective in generating vast T cell responses, BiVax/IL2Cx showed better control of tumor growth than TriVax. However, this effect was associated with high incidence of diabetes in an antigen and CD8 dependent fashion. T cell responses generated by BiVax/IL2Cx, but not those generated by TriVax were highly resistant to PD-1/PD-L1 inhibitory signals. Nevertheless, PD-1 blockade enhanced the ability of TriVax to control tumor growth but increased the incidence of diabetes. Finally, we show that severe autoimmunity by BiVax/IL2Cx was prevented while preserving outstanding antitumor responses by utilizing a tumor antigen not expressed in the pancreas. Our data provides a clear evidence that peptide based vaccines can expand vast endogenous T cell responses which effectively control tumor growth but with high potential of autoimmune pathology.

Immunoliposome co-delivery of bufalin and anti-CD40 antibody adjuvant induces synergetic therapeutic efficacy against melanoma

Liposomes constitute one of the most popular nanocarriers for improving the delivery and efficacy of agents in cancer patients. The purpose of this study was to design and evaluate immunoliposome co-delivery of bufalin and anti-CD40 to induce synergetic therapeutic efficacy while eliminating systemic side effects. Bufalin liposomes (BFL) conjugated with anti-CD40 antibody (anti-CD40-BFL) showed enhanced cytotoxicity compared with bufalin alone. In a mouse B16 melanoma model, intravenous injection of anti-CD40-BFL achieved smaller tumor volume than did treatment with BFL (average: 117 mm³ versus 270 mm³, respectively); the enhanced therapeutic efficacy through a caspase-dependent pathway induced apoptosis, which was confirmed using terminal deoxynucleotidyl transferase-mediated dUTP-Fluorescein nick end labeling and Western blot assay. Meanwhile, anti-CD40-BFL elicited unapparent body-weight changes and a significant reduction in serum levels of tumor necrosis factor-α, interleukin-1β, interleukin-6, interferon-γ, and hepatic enzyme alanine transaminase, suggesting minimized systemic side effects. This may be attributed to the mechanism by which liposomes are retained within the tumor site for an extended period of time, which is supported by the following biodistribution and flow cytometric analyses. Taken together, the results demonstrated a highly promising strategy for liposomal vehicle transport of anti-CD40 plus bufalin that can be used to enhance antitumor effects via synergetic systemic immunity while blocking systemic toxicity.

Targeting the IL-12/IL-23 axis: An alternative approach to removing tumor induced immune suppression

Combination immune checkpoint blockade has demonstrated significant clinical responses in cancers infiltrated by T cells. Many tumors contain high proportions of myeloid cells and these can secrete immunosuppressive cytokines like IL-23. Our data suggest the clinical potential of using anti-CD40 (push) and anti-IL-23 mAbs (pull) to tip the IL-12/23 balance in established tumors and act as an alternative combination cancer immunotherapy.

Antitumor activities of agonistic anti-TNFR antibodies require differential FcγRIIB coengagement in vivo

Agonistic anti-TNF receptor (TNFR) superfamily member antibodies are a class of promising antitumor therapies in active clinical investigation. An unexpected requirement for inhibitory Fcγ receptor FcγRIIB coengagement has recently been described for their in vivo antitumor activities. Although these findings have informed the design of more potent antitumor agonistic, anti-TNFR therapies, the underlying mechanism has remained obscure. Through detailed genetic analysis of strains conditionally deleted for FcγRIIB on defined cellular populations or mutated in specific signaling components, we now demonstrate that different agonistic anti-TNFR antibodies have specific requirements for FcγRIIB expression on defined cellular populations and function in trans in the absence of FcγRIIB signaling components, thus supporting a general mechanism of FcγRIIB cross-linking in vivo for the activities of these antibodies.