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.

An engineered T-cell engager with selectivity for high mesothelin-expressing cells and activity in the presence of soluble mesothelin

Mesothelin (MSLN) is an attractive immuno-oncology target, but the development of MSLN-targeting therapies has been impeded by tumor shedding of soluble MSLN (sMSLN), on-target off-tumor activity, and an immunosuppressive tumor microenvironment. We sought to engineer an antibody-based, MSLN-targeted T-cell engager (αMSLN/αCD3) with enhanced ability to discriminate high MSLN-expressing tumors from normal tissue, and activity in the presence of sMSLN. We also studied the in vivo antitumor efficacy of this molecule (NM28-2746) alone and in combination with the multifunctional checkpoint inhibitor/T-cell co-activator NM21-1480 (αPD-L1/α4-1BB). Cytotoxicity and T-cell activation induced by NM28-2746 were studied in co-cultures of peripheral blood mononuclear cells and cell lines exhibiting different levels of MSLN expression, including in the presence of soluble MSLN. Xenotransplant models of human pancreatic cancer were used to study the inhibition of tumor growth and stimulation of T-cell infiltration into tumors induced by NM28-2746 alone and in combination with NM21-1480. The bivalent αMSLN T-cell engager NM28-2746 potently induced T-cell activation and T-cell mediated cytotoxicity of high MSLN-expressing cells but had much lower potency against low MSLN-expressing cells. A monovalent counterpart of NM28-2746 had much lower ability to discriminate high MSLN-expressing from low MSLN-expressing cells. The bivalent molecule retained this discriminant ability in the presence of high concentrations of sMSLN. In xenograft models, NM28-2746 exhibited significant tumor suppressing activity, which was significantly enhanced by combination therapy with NM21-1480. NM28-2746, alone or in combination with NM21-1480, may overcome shortcomings of previous MSLN-targeted immuno-oncology drugs, exhibiting enhanced discrimination of high MSLN-expressing cell activity in the presence of sMSLN.

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.

844 A trispecific ROR1 x CD3 T cell engager mediates in vitro tumor cell killing and in vivo tumor eradication

Background

Receptor tyrosine kinase-like orphan receptor 1 (ROR1) is expressed on a variety of difficult to treat solid and hematological malignancies. Several therapeutic concepts targeting ROR1 are currently in clinical studies, including antibody-drug conjugates (ADCs), chimeric antigen receptor engineered T cells, as well as a bispecific T cell engager. In contrast to ADCs, T cell engagers have the capacity to induce tumor cell depletion irrespective of tumor cell mitotic activity. For the therapy of ROR1 expressing tumors, we engineered a T cell engager with prolonged half-life to support convenient administration schemes.

Methods

NM32-2668, a ROR1-targeting T cell engager with prolonged serum half-life was engineered by joining three humanized rabbit antibody variable region (Fv) fragments specific for ROR1, CD3ɛ, and serum albumin, into our tri-specific scMATCHTM3 format. Each Fv fragment was stabilized using the ʎ-capTM technology. NM32-2668 was tested in assays for specific tumor lysis, induction of T cell proliferation, and cytokine release. These studies were performed using human T cells co-cultured with tumor cell lines and human tumor samples expressing various levels of ROR1. In vivo xenograft mouse studies were conducted using a human mantle cell lymphoma model in NCG mice engrafted with human PBMCs.

Results

Here we report the design and the promising preclinical activity of the scMATCHTM3 ROR1/CD3/hSA T cell engager NM32-2668 in vitro and in vivo. Importantly, we demonstrate potent and specific cytotoxic activity in the sub-nanomolar range on tumor cell lines expressing different levels of ROR1. NM32-2668 also mediates ROR1 dependent T cell activation and cytokine release. We observe robust tumor cell killing activity of NM32-2668 over an extended time period and at multiple ratios of effectors to targets in a real time imaging-based cytotoxicity assay. This molecule also mediates T cell proliferation in response to target cell binding. NM32-2668 mediates in vitro lysis of CLL patient tumor cells, T cell activation, and cytokine release, with minimal IL-6 involvement. In an in vivo mantle cell lymphoma model (Jeko-1) engrafted with human PBMCs, we observe tumor regression and eradication.

Conclusions

Collectively, these data demonstrate robust anti-tumor efficacy by NM32-2668, a scMATCHTM3 ROR1/CD3/hSA. Our results demonstrate that NM32-2668 promotes ROR1 dependent T cell activation and proliferation, as well as T cell-mediated tumor cell lysis. The activity of NM32-2668 has the potential to provide significant benefit to patients with ROR1+ malignancies on a convenient dosing schedule. We intend to rapidly progress NM32-2668 to clinical development.

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.

[Local reactions after repeated tetanus vaccinations]

Subjects who had exhibited a strong local reaction after vaccination with tetanus toxoid showed a high serum antitoxin titer. This observation confirms earlier findings published in the United States. Since the falloff rate in tetanus antitoxin, year by year, is no more than 30%, such patients should not receive a new booster injection in the following 10 years unless the risk of tetanus is considered great. When boostering these persons, the dose of tetanus toxoid can be reduced to 1-2 Lf.

[Booster vaccination with a diphtheria-tetanus vaccine for dermo-jet with low diphtheria toxoid content]

Indications are provided on how the organization of polyvaccinations against tuberculosis, poliomyelitis and diphtheria-tetanus in school collectivities can be rationalized. 19 persons aged 19-20 years were vaccinated intradermally with 1.5 Lf diphtheria toxoid and 15 Lf tetanus toxoid (contained in 0.1 ml) by means of a single injection with a jet injector (Dermo-Jet). In cases which had not previously been immunized, vaccination with the toxoid doses employed did not induce detectable antitoxin titers. In all cases which had previously been immunized the antitoxin titers after the booster injection were at least 400 times higher than the protection threshold for diphtheria and 1700 times higher than the protection threshold for tetanus. This was also the case in preimmunized cases which had no detectable antitoxin titer before the vaccination. The increase in antitoxin titer was inversely proportional to the prevaccinal titer in the manner of a logarithmic exponential function. It may be concluded from these results that the benefit of a booster vaccination is particularly high in poorly immunized persons whereas it is clearly limited in cases showing a high prevaccinal titer. The well tolerated intradermal vaccination with the jet injector (Dermo-Jet) can be considered as equivalent to the subcutaneous technic. From the point of view of organization (time consumption, problems of sterilization) this method is much preferable to intramuscular or subcutaneous vaccination.