A Bispecific, Tetravalent Antibody Targeting Inflammatory and Pruritogenic Pathways in Atopic Dermatitis

Inhibition of IL-4/IL-13 signaling has dramatically improved the treatment of atopic dermatitis (AD). However, in many patients, clinical responses are slow to develop and remain modest. Indeed, some symptoms of AD are dependent on IL-31, which is only partially reduced by IL-4/IL-13 inhibition. Thus, there is an unmet need for AD treatments that concomitantly block IL-4/IL-13 and IL-31 pathways. We engineered NM26-2198, a bispecific tetravalent antibody designed to accomplish this task. In reporter cell lines, NM26-2198 concomitantly inhibited IL-4/IL-13 and IL-31 signaling with a potency comparable with that of the combination of an anti-IL-4Rα antibody (dupilumab) and an anti-IL-31 antibody (BMS-981164). In human PBMCs, NM26-2198 inhibited IL-4-induced upregulation of CD23, demonstrating functional binding to FcγRII (CD32). NM26-2198 also inhibited the secretion of the AD biomarker thymus and activation-regulated chemokine (TARC) in blood samples from healthy human donors. In male cynomolgus monkeys, NM26-2198 exhibited favorable pharmacokinetics and significantly inhibited IL-31-induced scratching at a dose of 30 mg/kg. In a repeat-dose, good laboratory practice toxicology study in cynomolgus monkeys, no adverse effects of NM26-2198 were observed at a weekly dose of 125 mg/kg. Together, these results justify the clinical investigation of NM26-2198 as a treatment for moderate-to-severe AD.

Engineering of a trispecific tumor-targeted immunotherapy incorporating 4-1BB co-stimulation and PD-L1 blockade

Co-stimulatory 4-1BB receptors on tumor-infiltrating T cells are a compelling target for overcoming resistance to immune checkpoint inhibitors, but initial clinical studies of 4-1BB agonist mAbs were accompanied by liver toxicity. We sought to engineer a tri-specific antibody-based molecule that stimulates intratumoral 4-1BB and blocks PD-L1/PD-1 signaling without systemic toxicity and with clinically favorable pharmacokinetics. Recombinant fusion proteins were constructed using scMATCH3 technology and humanized antibody single-chain variable fragments against PD-L1, 4-1BB, and human serum albumin. Paratope affinities were optimized using single amino acid substitutions, leading to design of the drug candidate NM21-1480. Multiple in vitro experiments evaluated pharmacodynamic properties of NM21-1480, and syngeneic mouse tumor models assessed antitumor efficacy and safety of murine analogues. A GLP multiple-dose toxicology study evaluated its safety in non-human primates. NM21-1480 inhibited PD-L1/PD-1 signaling with a potency similar to avelumab, and it potently stimulated 4-1BB signaling only in the presence of PD-L1, while exhibiting an EC₅₀ that was largely independent of PD-L1 density. NM21-1480 exhibited high efficacy for co-activation of pre-stimulated T cells and dendritic cells. In xenograft models in syngeneic mice, NM21-1480 induced tumor regression and tumor infiltration of T cells without causing systemic T-cell activation. A GLP toxicology study revealed no evidence of liver toxicity at doses up to 140 mg/kg, and pharmacokinetic studies in non-human primates suggested a plasma half-life in humans of up to 2 weeks. NM21-1480 has the potential to overcome checkpoint resistance by co-activating tumor-infiltrating lymphocytes without liver toxicity.

Abstract 2871: NM28-2746, a reduced affinity bivalent mesothelin-binding MATCH4 T cell engager, with half-life extension, increases selectivity for killing of mesothelin-overexpressing cells

CD3-based T cell engagers are highly potent therapeutic molecules which enable T cell-mediated cytotoxic activity toward cells expressing selected tumor-associated antigens. Alongside a highly potent anti-tumor activity, is the risk of on-target off-tumor side effects due to low levels of expression of the target antigen in normal tissue. We have sought to overcome this issue with the design and generation of a target-density-dependent activation mechanism. We have generated reduced-affinity antibody fragments to the tumor associated antigen mesothelin and constructed a multi-domain MATCH4 molecule encompassing bivalent mesothelin binding domains, a CD3 binding domain, and a human serum albumin (HSA)-binding domain for half-life extension. Here we report the design of the MATCH4 molecule and the preclinical activity of the molecule in vitro and in vivo. We also report the biochemical characteristics of the therapeutic candidate molecule showing its highly favorable properties for clinical development. We demonstrate that the bivalent mesothelin T cell engager has increased in vitro potency in T cell activation and tumor cell killing in the presence of high mesothelin expressing cells, when compared to a higher-affinity monovalent counterpart. We also demonstrate that the activity on low mesothelin expressing cells, such as healthy mesothelial cells, is reduced for the bivalent molecule compared to the higher affinity monovalent molecule. Due to the shedding of mesothelin from the surface of cancer cells and the high circulating levels of soluble mesothelin in patient sera, we also demonstrate that the bivalent molecule is still highly potent in cytotoxic activity in the presence of concentrations of soluble mesothelin up to 500 ng/ml. We also demonstrate dose dependent anti-tumor activity in in vivo efficacy studies in PBMC-reconstituted mice, and combination therapeutic activity with an anti-PD-L1, anti-4-1BB bispecific molecule (NM21-1480). Collectively, these data demonstrate an increased selectivity to mesothelin-overexpressing cells by this novel MATCH4 reduced affinity bivalent T cell engager. These data indicate the potential of this molecule to increase the therapeutic window by reducing safety concerns on normal tissue where mesothelin expression is low, and yet promote cytotoxicity on mesothelin over-expressing cancer cells.

Citation Format: Bithi Chatterjee, Christian Hess, Daniel Snell, Tea Gunde, Stefan Warmuth, Alexandre Simonin, Matthias Brock, Fabio Spiga, Maria Johansson, Christopher Weinert, Julia Tietz, Niels Kirk, Nicole Bassler, Dana Mahler, Dania Diem, Alessandra Carrella, Noreen Giezendanner, Alessandra Alberti, Giorgio Gambino, Belinda Wickihalder, Bettina Bommer, Simone Muntwiler, Yasemin Yaman, Naomi Flueckiger, Robin Heiz, Sandro Wagen, David Urech. NM28-2746, a reduced affinity bivalent mesothelin-binding MATCH4 T cell engager, with half-life extension, increases selectivity for killing of mesothelin-overexpressing cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2871.

Abstract 2870: Dose selection investigations and combination strategies of NM21-1480, a PD-L1/4-1BB/HSA trispecific MATCH3 therapeutic clinical candidate

Antagonistic molecules targeting the PD-1/PD-L1 axis have shown excellent activity in the clinic. However, the majority of patients do not respond to the therapy due to multifaceted reasons implicating a non-effective activation of the immune system in those patients. The co-stimulatory molecule 4-1BB has been shown to be a key signalling component of T cells and the combination of 4-1BB activation and PD-1/PD-L1 antagonism has been shown to be highly active in preclinical models. Systemic application of first-generation anti-4-1BB antibodies however have resulted in dose limiting hepatic toxicities. We have generated and are currently clinically investigating a novel 4-1BB/PD-L1/HSA trispecific MATCH3 immunomodulatory drug candidate (NM21-1480) that agonizes 4-1BB conditionally upon PD-L1 binding and concomitantly blocks the interaction between PD-1 and PD-L1. Here we investigate the impact of dose dependency in vitro and the translation of this to in vivo studies to aid the selection of optimal doses for our ongoing clinical study of NM21-1480 in cancer patients. In human PD-L1 tumor bearing mice, triple knock-in for human PD-1, human PD-L1 and human 4-1BB, we have investigated the impact of dose titrations of NM21-1480. We observe a dose dependent effect of NM21-1480 on tumor growth, systemic exposure, tumor exposure and pharmacodynamic biomarkers of immune cell activation. We also demonstrate the formation of a memory response in treated mice through rechallenge of the mice with tumor. We also investigate the effect of combination therapy of NM21-1480 with immune-oncology targeted therapeutics both in vitro and in vivo. In particular, we demonstrate that the combination of NM21-1480 with anti-CD3 T cell engagers is highly effective in T cell activation and tumor control. These data highlight the potential of NM21-1480 for the treatment of cancer patients and enable greater understanding of the relationship between dose, tumor exposure, immune activation and tumor growth inhibition.

Citation Format: Daniel Snell, Tea Gunde, Stefan Warmuth, Peter Lichtlen, Linlin Liu, Shu-wen Teng, Lan Zhang, ChaoHsuan Pan, Peiqi Li, Julia Tietz, Matthias Brock, Alexandre Simonim, Christian Hess, Christopher Weinert, Maria Johansson, Bithi Chatterjeee, Nicole Bassler, Niels Kirk, Catia Mendes, Robin Heiz, Naomi Flueckiger, Dania Diem, Dana Mahler, Belinda Wickihalder, Simone Muntwiler, Sandro Wagen, Elmar vom Baur, Archie N. Tse, David Urech. Dose selection investigations and combination strategies of NM21-1480, a PD-L1/4-1BB/HSA trispecific MATCH3 therapeutic clinical candidate [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2870.

Abstract 2276: Preclinical development and mechanism of action studies of NM21-1480, a PD-L1/4-1BB/HSA trispecific MATCH3 therapeutic clinical candidate

Antagonistic molecules targeting the PD-1/PD-L1 axis have shown excellent activity in the clinic. However the majority of patients do not respond to the therapy due to multifaceted reasons implicating a non-effective activation of the immune system in those patients. The co-stimulatory molecule 4-1BB has been shown to be a key signalling component of T cells and the combination of 4-1BB activation and PD-1/PD-L1 antagonism has been shown to be highly active in preclinical models. Systemic application of first generation anti-4-1BB antibodies however have resulted in dose limiting hepatic toxicities. We have generated a novel 4-1BB/PD-L1/HSA trispecific MATCH3 immunomodulatory drug candidate (NM21-1480) that agonizes 4-1BB conditionally upon PD-L1 binding / blockade. Here we show the preclinical development data package for NM21-1480 demonstrating exquisite tumour-specific T cell activation associated with both 4-1BB agonism as well as PD-L1/PD-1 antagonism. We also demonstrate tumour specific localisation and accumulation of NM21-1480 in a mouse xenograft model. We report on the toxicity profile and pharmacokinetic properties of the molecule in non-human primates. We plan to initiate a first-in-human clinical study in the second half of 2020 to determine the safety, tolerability and first signs of clinical activity of the molecule.

Citation Format: Daniel Snell, Tea Gunde, Stefan Warmuth, Peter Lichtlen, Julia Tietz, Matthias Brock, Alexandre Simonin, Christian Hess, Weinert Christopher, Robin Heiz, Naomi Flueckiger, Julia Zeberer, Dania Diem, Dana Mahler, Diego Morenzoni, Belinda Wickihalder, Simone Muntwiler, Antonia Poelderl, Benjamin Kuettner, Sandro Wagen, Sebastian Meyer, Timothy Egan, David Urech. Preclinical development and mechanism of action studies of NM21-1480, a PD-L1/4-1BB/HSA trispecific MATCH3 therapeutic clinical candidate [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2276.

Abstract 1532: A novel, monovalent tri-specific antibody-based molecule that simultaneously modulates PD-L1 and 4-1BB exhibits potent anti-tumoral activity in vivo

The combined immunomodulation of PD-L1/PD-1 and 4-1BB is considered a promising strategy to increase response rates among cancer patients who are eligible to receive PD-L1/PD-1 inhibitors. Unfortunately, encouraging pre-clinical results achieved with such regimens have not yet translated into durable clinical success, due to addition of 4-1BB-agonistic antibodies being either intolerable at effective doses or ineffective, despite tolerability, at all doses. To eliminate this safety/efficacy tradeoff, we engineered a novel, tri-specific immunomodulatory drug candidate. The molecule consists of three monovalent antibody Fvs - specific for PD-L1, serum albumin (SA) and 4-1BB - fused in a single chain (a PD-L1/4-1BB/SA tri-specific scDb-scFv). The monovalent and Fc-less structure of the molecule ensures that 4-1BB agonism is conditional upon drug-mediated formation of an immunological synapse between PD-L1+ cells and 4-1BB+ cells, thereby restricting costimulation of 4-1BB+ cells to the tumor microenvironment (TME). Therefore, the scDb-scFv molecule avoids the extratumoral costimulation of immune cells that is believed to cause the dose-limiting toxicities that arise from therapeutic 4-1BB agonism. Meanwhile, the αSA domain extends the molecule’s serum half-life and is expected to promote delivery to the TME. In the present study, we demonstrate that a novel PD-L1/4-1BB/SA tri-specific scDb-scFv potently blocks PD-L1/PD-1 signaling and elicits T cell costimulation solely in the presence of PD-L1+ cells. In in vitro experiments, the scDb-scFv molecule exhibits a greater capacity to costimulate T cells than combinations of clinical stage α4-1BB and αPD-L1/PD-1 IgGs. Moreover, in contrast to ADCC-enabled αPD-L1 IgGs, the Fc-less scDb-scFv spared CD11c+ monocytes from depletion. We also demonstrate that the carefully balanced relative affinity between the molecule’s component αPD-L1 and α4-1BB Fvs maximizes its pharmacological activity and avoids bell-shaped dose-response curves. Next, in vivo efficacy was demonstrated in two xenograft models - HCC827 NCSLC and HCC1954 breast carcinoma - using humanized mice. While equally effective at slowing tumor progression in vivo, the PD-L1/4-1BB/SA tri-specific scDb-scFv was better tolerated, and was more pro-proliferative vis-à-vis intratumoral CD8+ T cells, than combined αPD-L1 and α4-1BB IgGs. In PK/PD studies in cynomologus monkeys, we confirmed the tolerability, pharmacological activity and extended serum half-life of the scDb-scFv molecule. Finally, the molecule was produced from stable CHO cells at high titers (comparable to IgGs) and exhibits outstanding stability characteristics. In conclusion, our data confirm the successful development of a novel therapeutic that is designed to unlock the full potential of combined immunomodulation and overcome its present limitations.

Citation Format: Tea Gunde, Matthias Brock, Stefan Warmuth, Alexandre Simonin, Christian Hess, Eva Oswald, Julia Tietz, Julia Zeberer, Dana Mahler, Simone Muntwiler, Benjamin Küttner, Belinda Wickihalder, Antonia Pölderl, Dania Diem, Teddy Beltrametti, Robin Heiz, Sebastian Meyer, Timothy Egan, David Urech. A novel, monovalent tri-specific antibody-based molecule that simultaneously modulates PD-L1 and 4-1BB exhibits potent anti-tumoral activity in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1532.

gespeR: a statistical model for deconvoluting off-target-confounded RNA interference screens

Small interfering RNAs (siRNAs) exhibit strong off-target effects, which confound the gene-level interpretation of RNA interference screens and thus limit their utility for functional genomics studies. Here, we present gespeR, a statistical model for reconstructing individual, gene-specific phenotypes. Using 115,878 siRNAs, single and pooled, from three companies in three pathogen infection screens, we demonstrate that deconvolution of image-based phenotypes substantially improves the reproducibility between independent siRNA sets targeting the same genes. Genes selected and prioritized by gespeR are validated and shown to constitute biologically relevant components of pathogen entry mechanisms and TGF-β signaling. gespeR is available as a Bioconductor R-package.

Simultaneous analysis of large-scale RNAi screens for pathogen entry

BACKGROUND

Large-scale RNAi screening has become an important technology for identifying genes involved in biological processes of interest. However, the quality of large-scale RNAi screening is often deteriorated by off-targets effects. In order to find statistically significant effector genes for pathogen entry, we systematically analyzed entry pathways in human host cells for eight pathogens using image-based kinome-wide siRNA screens with siRNAs from three vendors. We propose a Parallel Mixed Model (PMM) approach that simultaneously analyzes several non-identical screens performed with the same RNAi libraries.

RESULTS

We show that PMM gains statistical power for hit detection due to parallel screening. PMM allows incorporating siRNA weights that can be assigned according to available information on RNAi quality. Moreover, PMM is able to estimate a sharedness score that can be used to focus follow-up efforts on generic or specific gene regulators. By fitting a PMM model to our data, we found several novel hit genes for most of the pathogens studied.

CONCLUSIONS

Our results show parallel RNAi screening can improve the results of individual screens. This is currently particularly interesting when large-scale parallel datasets are becoming more and more publicly available. Our comprehensive siRNA dataset provides a public, freely available resource for further statistical and biological analyses in the high-content, high-throughput siRNA screening field.

Innate signaling regulates cross-priming at the level of DC licensing and not antigen presentation

Innate stimuli, such as TLR ligands, are known to greatly facilitate cross-priming. Currently it is unclear whether innate stimuli enhance cross-priming at the level of cross-presentation or at the level of T-cell priming. In this study, we addressed this question by measuring cross-presentation as well as cross-priming by virus-like particles (VLP) displaying peptide p33 derived of lymphocytic choriomeningitis virus. Innate stimuli were varied by either packaging different TLR ligands into virus-like particles or using mice deficient in two key molecules of TLR-signaling, namely the adaptor molecule MyD88 as well as IFN-alpha/beta receptor. While efficient cross-presentation occurred despite strongly reduced activation of DC in the absence of TLR ligand-mediated signals, T-cell priming was abolished. Thus, innate stimuli regulate cross-priming at the level of DC licensing for T-cell activation and not antigen presentation.

Cutting edge: limited specialization of dendritic cell subsets for MHC class II-associated presentation of viral particles

Dendritic cells (DCs) are the most important APC. It was recently reported that there is a dichotomy for Ag presentation by DC subsets; exogenous Ags reach the MHC class I pathway, but not the MHC class II pathway, in CD8(+) DCs, whereas CD8(-) DCs only process Ags for the MHC class II pathway. In this study, we used virus-like particles (VLPs) to show that CD8(+) and CD8(-) DCs efficiently capture and process VLPs for presentation in association with MHC class II in vivo. In contrast, CD8(+) DCs, but not CD8(-) DCs, cross presented VLP-derived peptides. This pattern was changed in an FcgammaR-dependent fashion in the presence of VLP-specific Abs, because under those conditions both DC subsets failed to efficiently cross present. Thus, the presentation of viral particles to CD4(+) T cells is not restricted to distinct DC subsets, whereas the presentation of viral particles to CD8(+) T cells is limited to CD8(+) DCs.

Displaying Fel d1 on virus-like particles prevents reactogenicity despite greatly enhanced immunogenicity: a novel therapy for cat allergy

Allergen-specific desensitization is the only disease-modifying therapy currently available for the treatment of allergies. These therapies require application of allergen over several years and some may induce life-threatening anaphylactic reactions. An ideal vaccine for desensitization should be highly immunogenic and should alleviate allergic symptoms upon few injections while being nonreactogenic. We describe such a vaccine for the treatment of cat allergy, consisting of the major cat allergen Fel d1 coupled to bacteriophage Qβ-derived virus-like particles (Qβ–Fel d1). Qβ–Fel d1 was highly immunogenic, and a single vaccination was sufficient to induce protection against type I allergic reactions. Allergen-specific immunoglobulin G antibodies were shown to be the critical effector molecules and alleviated symptoms by two distinct mechanisms. Although allergen-induced systemic basophil degranulation was inhibited in an FcγRIIb-dependent manner, inhibition of local mast cell degranulation in tissues occurred independently of FcγRIIb. In addition, treatment with Qβ–Fel d1 abolished IgE memory responses upon antigen recall. Despite high immunogenicity, the vaccine was essentially nonreactogenic and vaccination induced neither local nor systemic anaphylactic reactions in sensitized mice. Moreover, Qβ–Fel d1 did not induce degranulation of basophils derived from human volunteers with cat allergies. These data suggest that vaccination with Qβ–Fel d1 may be a safe and effective treatment for cat allergy.

Secretory phospholipase A2-IID is an effector molecule of CD4+CD25+ regulatory T cells

Suppression by natural CD4(+)CD25(+) regulatory T cells (Tregs) is one mechanism by which tolerance is maintained. However, the way in which Tregs mediate suppression is not well understood. Here, we show that secreted phospholipase A2 (sPLA2)-IID is selectively produced by Tregs. sPLA2-IID is a potent mediator of Treg function, because it strongly suppressed proliferation of CD4(+) and CD8(+) T cells in vitro and in vivo in a manner independent of its catalytic activity. Furthermore, sPLA2-IID promoted the differentiation of Tregs, presumably via attenuating signaling through the PI3K/Akt/mammalian target of rapamycin pathway. Importantly, administration of a sPLA2-IID-Fc fusion protein inhibited disease development in murine models of colitis and multiple sclerosis, suggesting that sPLA2-IID's immunosuppressive function might be exploited therapeutically.