scholarly journals 769 A single dose of intratumoral TransCon™ TLR7/8 agonist monotherapy promoted sustained activation of antigen presenting cells resulting in CD4+ and CD8+ T cell activation and tumor growth inhibition

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A804-A804
Author(s):  
Luis Zuniga ◽  
Karan Uppal ◽  
Kathy Bang ◽  
Enping Hong ◽  
Simran Sabharwal ◽  
...  
Keyword(s):  
T Cells ◽  
Tumor Growth ◽  
Growth Inhibition ◽  
Tumor Antigen ◽  
Tumor Growth Inhibition ◽  
Tlr Agonists ◽  
Syngeneic Mouse ◽  
Antigen Presenting ◽  
Anti Tumor Activity ◽  
Dose Dependent

BackgroundThe use of pattern recognition receptor agonists (PRRAs) such as Toll-like receptor (TLR) agonists is an attractive approach for cancer immunotherapy. TLR agonism elicits anti-tumor activity by activating antigen presenting cells (APCs) to promote a proinflammatory microenvironment and anti-tumor immunity. Local delivery of TLR agonists has shown encouraging preclinical and clinical anti-tumor benefit. However, intratumoral (IT) delivery of naked PRRAs may lead to rapid effusion from the tumor microenvironment, potentially impacting their effectiveness in inducing local inflammation and may promote systemic cytokine release, increasing the risk of adverse effects.MethodsTransConTM TLR7/8 Agonist was designed to address the current limitations of PRRA therapies and IT delivery through sustained and controlled release of resiquimod, a potent TLR7/8 agonist, following IT administration of a hydrogel depot.ResultsA single IT injection of TransCon TLR7/8 Agonist induced potent tumor growth inhibition in a dose-dependent manner in syngeneic mouse CT26 tumors. Following IT TransCon TLR7/8 Agonist treatment, acute and sustained upregulation of cell surface markers indicative of activation of APCs, such as CD54, CD69, and CD86, in the tumor was observed by fluorescence activated flow cytometry (FACs). Additionally, TransCon TLR7/8 Agonist treatment was associated with an increase in the frequency of APCs with an activated phenotype in tumor draining lymph nodes (LNs). Further, a concomitant potentiation in the frequency of activated CD4 and CD8 T cells in tumor draining LNs following IT TransCon TLR7/8 Agonist treatment was observed, as demonstrated by increased expression of Ki67, ICOS, or granzyme B.ConclusionsThese data support that a single IT dose of TransCon TLR7/8 Agonist can mediate robust anti-tumor activity as a monotherapy in the CT26 syngeneic mouse tumor model while promoting local activation of intratumoral APCs. Such activation may promote tumor antigen uptake and migration to tumor-associated lymphoid tissue, as evidenced by an increase in APCs with an activated phenotype in tumor draining LNs following TransCon TLR7/8 Agonist treatment. Activated tumor antigen-bearing APCs can promote the priming and activation of tumor-specific T cells in the tumor-draining LNs. Consistently, a dose-dependent increase in the frequency of T cells with an activated effector phenotype in tumor draining LNs following administration of TransCon TLR7/8 Agonist was observed. These preclinical data further support TransCon TLR7/8 Agonist as a novel and potentially efficacious PRRA therapy. A clinical trial to evaluate safety and efficacy of TransCon TLR7/8 Agonist as monotherapy, and in combination with pembrolizumab, in cancer patients has been initiated (transcendIT-101; NCT04799054).Ethics ApprovalThe animal studies performed described were performed in accordance with the “Guide for the Care and Use of Laboratory Animals: Eighth Edition” and approved by the institutional animal care and use committee (IACUC).

scholarly journals Two novel human anti-CD25 antibodies with antitumor activity inversely related to their affinity and in vitro activity

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Deyong Song ◽  
Xiu Liu ◽  
Chuangchuang Dong ◽  
Qiaoping Wang ◽  
Chunjie Sha ◽  
...  
Keyword(s):  
T Cells ◽  
Tumor Growth ◽  
Growth Inhibition ◽  
Treg Cells ◽  
Tumor Growth Inhibition ◽  
In Vitro Activity ◽  
Limited Efficacy ◽  
Cancer Models ◽  
Excellent Candidate

AbstractHigh tumor regulatory T (Treg) cell infiltration is associated with poor prognosis of many cancers. CD25 is highly expressed on tumor Treg cells and is a potential target for Treg deletion. Previously characterized anti-CD25 antibodies appear to have limited efficacy in tumor inhibition. Here we identified two human anti-CD25 antibodies, BA9 and BT942, which did not prevent the activation of IL-2R signaling pathway by IL-2. BT942 had weaker binding and cytotoxic activity to human CD25-expressing cell lines than BA9. But both demonstrated significant tumor growth inhibition in early and late-stage animal cancer models. BT942 resulted in a higher expansion of CD8+ T cells and CD4+ T cells in tumor microenvironment in mouse MC38 model compared to BA9. BT942 also demonstrated significant higher tumor growth inhibition and higher expansion of CD8+ T cells and CD4+ T cells in combination with an anti-PD1 antibody. Pharmacokinetic study of BT942 in cynomolgus monkeys demonstrated a half-life of 206.97 ± 19.03 h. Structural analysis by cryo-EM revealed that BT942 recognizes an epitope on opposite side of the CD25-IL-2 binding site, consistent with no IL-2 signaling blockade in vitro. BT942 appears to be an excellent candidate for cancer immunotherapy.

scholarly journals 683 A novel mechanism of neuropilin-1 inhibition results in improved tumor growth inhibition in vivo

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A722-A722
Author(s):  
Eric Zhu ◽  
Daniel Blom ◽  
Shalini Sethumadhavan ◽  
Chengfeng Merriman ◽  
Katherine Molloy ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Tumor Growth ◽  
Growth Inhibition ◽  
Tumor Growth Inhibition ◽  
Factor V ◽  
Multiple Cancer ◽  
Neuropilin 1 ◽  
Cancer Models ◽  
Anti Tumor Activity

BackgroundNeuropilin-1 (NRP1) is a co-receptor that complexes with diverse ligands and their cognate receptors. As such, it plays a role in multiple different biological processes, including axon guidance and angiogenesis. NRP1 contains two CUB domains (a1 and a2) involved in binding the ligand Semaphorin3A (SEMA3A), two Factor V/VIII domains (b1 and b2) involved in VEGF ligand binding and one MAM domain (c domain). While functional antibodies with anti-tumor activity have been generated against the SEMA3A and VEGF binding domains, little attention has been paid to the c domain of NRP1, which has been implicated in the dimerization of NRP1, a prerequisite for functionality. We therefore hypothesized that c domain-binding antibodies would offer an opportunity to generate functional inhibitors of both SEMA3A and VEGF signaling and therefore improved anti-tumor activity.MethodsRecombinant human NRP1 comprising all subdomains was used to identify fully human anti-NRP1 antibodies. Specific antibodies were tested for their ability to block NRP1 interactions with recombinant SEMA3A and VEGF protein in vitro. Blocking antibodies were subsequently assessed for their functional effects, such as inhibition of SEMA3A-mediated growth cone collapse. Antibodies with diverse binding characteristics were then tested for in vivo anti-tumor activity in multiple cancer models of interest.ResultsRecombinant NRP1 containing the a1, a2, b1, b2 and c subdomains was used to successfully identify a series of specific monoclonal antibodies that cross-reacted with Cynomolgus monkey and mouse NRP1, but not human NRP2. Except for the a2 domain, epitope mapping showed an even distribution of mAbs for binding to each of the NRP1 subdomains, including the c domain that has been proposed to play a role in dimerization. Using biolayer interferometry, we identified antibody classes with direct SEMA3A and/or VEGF blocking properties. Further optimization of these antibodies yielded mAbs with subnanomolar affinities that showed significant tumor growth inhibition in multiple mouse models, including anti-PD1 non-responsive models.ConclusionsHere we demonstrate the identification of fully human monoclonal antibodies that specifically bind to the c domain of human NRP1. A subset of these c domain binders do not block either SEMA3A or VEGF binding to NRP1 but do show in vivo efficacy, suggesting a role for the c domain of NRP1 in the formation of functional (dimeric) complexes. Thus, c domain binding antibodies show remarkable inhibition of tumor growth in mouse cancer models and offer a novel means of therapeutic intervention in patients who are refractory to immune checkpoint inhibition.

scholarly journals Two Novel Human Anti-cd25 Antibodies With Antitumor Activity Inversely Related to Its Affinity and in Vitro Activity

2021 ◽  
Author(s):  
Deyong Song ◽  
Xiu Liu ◽  
Chuangchuang Dong ◽  
Chunjie Sha ◽  
Zhenfei Ning ◽  
...  
Keyword(s):  
T Cells ◽  
Tumor Growth ◽  
Growth Inhibition ◽  
Treg Cells ◽  
Tumor Growth Inhibition ◽  
In Vitro Activity ◽  
Limited Efficacy ◽  
Cancer Models ◽  
Excellent Candidate

Abstract High tumor regulatory T (Treg) cell infiltration is associated with poor prognosis of many cancers. CD25 is highly expressed on tumor Treg cells and is a potential target for Treg deletion. Previously characterized anti-CD25 antibodies appear to have limited efficacy. Here we identified two human anti-CD25 antibodies, BA9 and BT942, which demonstrated strong tumor growth inhibition in both early and late-stage animal cancer models. BT942 had weaker binding and cytotoxic activity to human CD25-expressing cell lines than BA9. But BT942 showed a stronger anti-tumor effect and resulted a higher expansion of CD8+ T cells and CD4+ T cells in tumor microenvironment at the mouse MC38 model compared to BA9. As CD25 is transiently expressed on activated Teff cells, it is likely that BT942 with lower affinity can distinguish high expression Treg and low expression Teff and therefore cannot kill Teff cells effectively. Such a combination of BT942’s abilities may underline its stronger effect. BT942 also demonstrated higher tumor growth inhibition in combination with an anti-PD1 antibody. Pharmacokinetic tests of BT942 in cynomolgus monkey demonstrated a half-life of 206.97±19.03 hours. No toxicity efficacy was seen in mice efficacy or monkey examinations. BT942 appears to be an excellent candidate for cancer immunotherapy.

scholarly journals Lactate Increases Stemness of CD8+ T Cells to Augment Anti-Tumor Immunity

2021 ◽  
Author(s):  
Qiang Feng ◽  
Zhida Liu ◽  
Xuexin Yu ◽  
Tongyi Huang ◽  
Jiahui Chen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Growth ◽  
Growth Inhibition ◽  
Tumor Immunity ◽  
Cd8 T Cells ◽  
Subcutaneous Administration ◽  
Tumor Growth Inhibition ◽  
Mouse Splenocytes

Nutrients and metabolites play important roles in immune functions. Recent studies show lactate instead of glucose can serve as a primary carbon fuel source for most tissues. The role of lactate in tumor immunity is not well understood with immune suppressive functions reported for lactic acid, the conjugate acid form of lactate. In this study, we report lactate increases the stemness of CD8+ T cells and augments anti-tumor immunity. Subcutaneous administration of lactate but not glucose shows CD8+ T cell-dependent tumor growth inhibition. Single cell transcriptomics analysis revealed lactate treatment increased a subpopulation of stem-like TCF-1-expressing CD8+ T cells, which is further validated by ex vivo culture of CD8+ T cells from mouse splenocytes and human peripheral blood mononuclear cells. The inhibition of histone deacetylase activity by lactate increased acetylation in the histone H3K27 site at the Tcf7 super enhancer locus and increased the gene expression of Tcf7. Adoptive transfer of CD8+ T cells pretreated with lactate in vitro showed potent tumor growth inhibition in vivo. Our results elucidate the immune protective role of lactate in anti-tumor immunity without the masking effect of acid. These results may have broad implications for T cell therapy and the understanding of lactate in immune metabolism.

scholarly journals AO-176, a Highly Differentiated Clinical Stage Anti-CD47 Antibody, Exerts Potent Anti-Tumor Activity in Preclinical Models of Multiple Myeloma As a Single Agent and in Combination with Approved Therapeutics

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 3-4
Author(s):  
William Casey Wilson ◽  
John Richards ◽  
Robyn J Puro ◽  
Gabriela Andrejeva ◽  
Ben J Capoccia ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Growth Inhibition ◽  
Clinical Stage ◽  
Single Agent ◽  
Standard Of Care ◽  
Tumor Growth Inhibition ◽  
Private Company ◽  
Xenograft Models ◽  
Rpmi 8226 ◽  
Anti Tumor Activity

Upregulation of tumor CD47, the "don't eat me" signal, to evade immune surveillance is a common escape mechanism that evolves during cancer development, progression, and relapse. Previous studies have shown multiple myeloma (MM) cells leverage this mechanism through broad upregulation of CD47 compared to non-malignant plasma cells, making CD47 an attractive therapeutic target for this disease. We recently reported that AO-176, a clinical stage humanized anti-CD47 IgG2 antibody, possesses differentiated characteristics such as preferential binding of tumor cells compared to normal cells, a lack of binding to red blood cells, non-ADCC direct tumor killing and elicits immunogenic cell death with DAMP induction, all in addition to single-agent phagocytosis. In this study, AO-176's anti-tumor activity in MM was evaluated. Immunohistochemical analyses of MM patient tumors with upregulated CD47 expression showed infiltration of innate immune cells such as macrophages and dendritic cells, both previously shown to be involved in anti-CD47 antibody mechanisms of action. AO-176 binding was confirmed on human cell lines frequently used in MM xenograft models. AO-176 exerted substantial single agent in vivo anti-tumor activity in multiple MM xenograft models when dosed at 25 mg/kg, including significant tumor growth inhibition of RPMI-8226 xenografted mice, and complete responses (CRs) in (10/10) NCI-H929 xenografted mice. These CRs were durable, with treated mice tumor-free up to 120 days post antibody dosing. Immunohistochemical analysis of AO-176 treated tumors from both models showed increased numbers of macrophages and dendritic cells compared to controls. An AO-176 dose response study resulted in CRs and increases in overall survival down to 10 mg/kg, with CRs observed as low as 3 mg/kg during dosing. In addition, we found that large NCI-H929 tumors (up to 1600mm3) showed pronounced regression after AO-176 treatment. The anti-tumor activity of AO-176 was also evaluated in combination with several standard of care MM therapies. When combined with the proteasome inhibitor bortezomib, AO-176 treatment at both 10 mg/kg and 25 mg/kg resulted in profound RPMI-8226 xenograft growth inhibition, near-total CRs (19/20 mice), and extended survival at both doses. Combining AO-176 and the anti-CD38 antibody daratumumab or immunomodulatory drugs (lenalidomide/pomalidomide) both produced significant enhancement of anti-tumor activity in xenograft models. The combined regimen of AO-176 with daratumumab led to significant MM.1S tumor growth inhibition compared to AO-176 or daratumumab alone. Both lenalidomide and pomalidomide combined with AO-176 resulted in significantly increased MM.1S tumor growth inhibition and extended survival compared to AO-176 alone, with an increased number of CRs observed in the combination groups compared to monotherapy groups. In summary, the pre-clinical potent single agent activity and enhanced activity when combined with standard of care anti-MM agents, warrants further development of AO-176 in MM treatment. AO-176 is being evaluated in phase 1 clinical trials for the treatment of patients with solid tumors (NCT03834948) and with MM (NCT04445701). Disclosures Wilson: Arch Oncology: Current Employment, Current equity holder in private company. Richards:Arch Oncology: Current Employment, Current equity holder in private company. Puro:Arch Oncology: Current Employment, Current equity holder in private company. Andrejeva:Arch Oncology: Current Employment, Current equity holder in private company. Capoccia:Arch Oncology: Current Employment, Current equity holder in private company. Donio:Arch Oncology: Current Employment, Current equity holder in private company. Hiebsch:Arch Oncology: Current Employment, Current equity holder in private company. Chakraborty:Arch Oncology: Current Employment, Current equity holder in private company. Sung:Arch Oncology: Current Employment, Current equity holder in private company. Pereira:Arch Oncology: Current Employment, Current equity holder in private company.

scholarly journals 16 Tumor growth inhibition mediated by a single dose of intratumoral TransCon™ TLR7/8 agonist was associated with activated circulating T and B cells and sustained low levels of systemic cytokines

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A18-A18
Author(s):  
Amer Mirza ◽  
Luis Zuniga ◽  
Karan Uppal ◽  
Kathy Bang ◽  
Enping Hong ◽  
...  
Keyword(s):  
T Cells ◽  
Immune Cells ◽  
Immune Cell ◽  
Innate Immune ◽  
Tumor Growth Inhibition ◽  
Innate Immune Cells ◽  
Tlr Agonists ◽  
Adaptive Immune ◽  
Cytokines And Chemokines ◽  
Anti Tumor Activity

BackgroundTLR agonists can elicit anti-tumor activity by activating innate immune cells and promoting a proinflammatory microenvironment. Local delivery of TLR agonists has shown encouraging preclinical and clinical anti-tumor activity. However, intratumoral (IT) delivery of naked TLR agonists such as resiquimod, a TLR7/8 agonist, can lead to rapid efflux from the tumor, resulting in acute high systemic drug exposure and transient but high level of peripheral proinflammatory cytokines, thus limiting anti-tumor benefit and increasing risk of cytokine-driven adverse effects.MethodsTransCon™ TLR7/8 Agonist was designed to elicit a sustained and local release of resiquimod following IT administration of a hydrogel depot. In the syngeneic murine CT26 tumor model, a single IT injection of TransCon TLR7/8 Agonist monotherapy was sufficient to induce potent tumor growth inhibition. Following treatment, the induction of key cytokines and chemokines associated with innate immunity was determined.ResultsProinflammatory cytokines (IL-1b, IL-6, and TNFα) were induced following IT TransCon TLR7/8 Agonist treatment, but in contrast to free resiquimod, peak levels were more than 10-fold lower than those observed with an equimolar dose of free resiquimod. The circulating levels of these cytokines were sustained above control alone through Day 21. TH1-associated IFNγ was induced with levels increased at Day 1 and maintained at Day 7. Additionally, expression of myeloid-associated chemokines (KC/GROa/CXCL1, MCP-1/CCL2, IP-10/CXCL10, and MIP-1a/CCL3) were induced and sustained in a largely dose-dependent manner through Day 21. The sustained increase in cytokines was consistent with an increase in circulating innate immune cells, such as NK and myeloid cells. Furthermore, evidence of adaptive immune cell activation was observed as indicated by expression of Ly6C, ICOS and Ki67, which were increased on CD8+ T cells, CD4+ T cells (Ki67, ICOS), and B cells (Ly6C).ConclusionsThese data show that a single IT injection of TransCon TLR7/8 Agonist can elicit sustained expression of key cytokines and chemokines, promote innate immune cell mobilization, activate adaptive immune cells, and mediate robust anti-tumor activity. The levels of the cytokines remained relatively low through the observation period of 21 days, suggesting a low risk of systemic cytokine-associated adverse events. The increase in activated B, T, and NK cells in blood was associated with induction of a potent anti-tumor response, further supporting TransCon TLR7/8 Agonist as a novel and potentially efficacious PRRA therapy. A clinical trial to evaluate its safety and efficacy in cancer patients is currently underway (transcendIT-101; NCT04799054).Ethics ApprovalThe animal studies described were performed in accordance with the ‘Guide for the Care and Use of Laboratory Animals: Eighth Edition’ and approved by the institutional animal care and use committee (IACUC).

Sign in / Sign up

Export Citation Format

Share Document