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.

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.