Logic-gated antibody pairs that selectively act on cells co-expressing two antigens

The use of therapeutic monoclonal antibodies is constrained because single antigen targets often do not provide sufficient selectivity to distinguish diseased from healthy tissues. We present HexElect®, an approach to enhance the functional selectivity of therapeutic antibodies by making their activity dependent on clustering after binding to two different antigens expressed on the same target cell. lmmunoglobulin G (lgG)-mediated clustering of membrane receptors naturally occurs on cell surfaces to trigger complement- or cell-mediated effector functions or to initiate intracellular signaling. We engineer the Fc domains of two different lgG antibodies to suppress their individual homo-oligomerization while promoting their pairwise hetero-oligomerization after binding co-expressed antigens. We show that recruitment of complement component C1q to these hetero-oligomers leads to clustering-dependent activation of effector functions such as complement mediated killing of target cells or activation of cell surface receptors. HexElect allows selective antibody activity on target cells expressing unique, potentially unexplored combinations of surface antigens.

Trust Within the Workplace: A Review of Two Waves of Research and a Glimpse of the Third

Over the past quarter century, trust has emerged as a core concept in organizational psychology and organizational behavior. We review the body of research amassed over that period using a field evolutionary lens and identify two “waves” that have shaped and progressed the field in specific and important ways: Wave 1, establishing foundational building blocks; Wave 2, questioning assumptions and examining alternatives. For each wave, we identify what has been learned and identify key questions that still need to be addressed. We also suggest researchers will need to evolve the fundamental questions asked in order to maintain the momentum of the literature into the next quarter century, and we speculate about what these might look like. Finally, as a result of recent organizational developments and societal disruptions, we anticipate the emergence of a third wave, aimed at examining their implications for trust in the workplace.

Abstract 1574: Preclinical evaluation of epcoritamab combined with standard of care therapies for the treatment of B-cell lymphomas

B-cell non-Hodgkin lymphoma (B-NHL) is a heterogeneous disease with an unmet medical need for new efficacious, well tolerated, off-the-shelf therapies that can combine with standard of care (SOC) regimens. Epcoritamab (GEN3013; DuoBody®-CD3×CD20) is a novel subcutaneously administered bispecific antibody with a manageable safety profile and promising preliminary anti-tumor activity in both aggressive and indolent B-NHL. Epcoritamab simultaneously binds to CD3 on T cells and to CD20-expressing tumor cells to induce potent T-cell-mediated killing. SOC treatments for B-NHL include rituximab in combination with chemotherapy regimens such as CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone), bendamustine, or immunomodulatory agents such as lenalidomide. These therapies have mechanisms of action distinct from that of epcoritamab, and mostly non-overlapping adverse event profiles. Previous preclinical studies demonstrated that epcoritamab can induce effective anti-tumor activity in the presence of a rituximab analog, supporting the combination of the two in clinical trials. Here, we present in vitro studies conducted to evaluate whether epcoritamab can be used in combination with current SOC therapies for B-NHL.

Healthy donor T cells as effector cells and/or CD20-expressing B-NHL tumor cell lines were pre-treated with each individual SOC component (lenalidomide, cyclophosphamide, doxorubicin, vincristine, prednisone) to evaluate the impact on T cells and target cell lines. Next, co-cultures of pre-treated T and B-NHL cells were incubated with the same SOC component in the presence of epcoritamab, and T-cell mediated cytotoxicity and associated T-cell activation were assessed by flow cytometry. Bendamustine was added together with epcoritamab during the T-cell activation and cytotoxicity assay to assess potential antagonizing effect.

Lenalidomide enhanced T-cell activation induced by CD3 crosslinking with immobilized anti-CD3 or epcoritamab, resulting in higher potency of these T cells to exert epcoritamab-induced cytotoxicity of CD20-expressing tumor cells. T cells pre-treated with individual CHOP components were capable of mediating epcoritamab-induced cytotoxicity. Finally, bendamustine did not antagonize T-cell activation and had an additive effect on T-cell-mediated cytotoxicity by epcoritamab. These preclinical data indicate that epcoritamab-can be combined with these SOC agents.

In conclusion, these data warrant clinical evaluation of epcoritamab combinations with multiple SOC therapies. Given the promising single-agent activity of epcoritamab, these combinations may lead to deep and durable responses that can translate into improved long-term outcomes for B-NHL patients. Epcoritamab combination therapies are planned to be evaluated in a clinical trial sponsored by Genmab and Abbvie.

Citation Format: Christopher W. Chiu, Ida H. Hiemstra, Wessel ten Hagen, Rajaa Snijdewint-Nkairi, Bart de Jong, Roberto S. Oliveri, Brian Elliot, Edith Szafer-Glusman, Danita Schuurhuis, Julie Blaedel, Tahamatan Ahmadi, Esther Breij, A. Kate Sasser, Maria Jure-Kunkel. Preclinical evaluation of epcoritamab combined with standard of care therapies for the treatment of B-cell lymphomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1574.

Dual Epitope Targeting and Enhanced Hexamerization by DR5 Antibodies as a Novel Approach to Induce Potent Antitumor Activity Through DR5 Agonism

Higher-order death receptor 5 (DR5) clustering can induce tumor cell death; however, therapeutic compounds targeting DR5 have achieved limited clinical efficacy. We describe HexaBody-DR5/DR5, an equimolar mixture of two DR5-specific IgG1 antibodies with an Fc-domain mutation that augments antibody hexamerization after cell surface target binding. The two antibodies do not compete for binding to DR5 as demonstrated using binding competition studies, and binding to distinct epitopes in the DR5 extracellular domain was confirmed by crystallography. The unique combination of dual epitope targeting and increased IgG hexamerization resulted in potent DR5 agonist activity by inducing efficient DR5 outside-in signaling and caspase-mediated cell death. Preclinical studies in vitro and in vivo demonstrated that maximal DR5 agonist activity could be achieved independent of Fc gamma receptor-mediated antibody crosslinking. Most optimal agonism was observed in the presence of complement complex C1, although without inducing complement-dependent cytotoxicity. It is hypothesized that C1 may stabilize IgG hexamers that are formed after binding of HexaBody-DR5/DR5 to DR5 on the plasma membrane, thereby strengthening DR5 clustering and subsequent outside-in signaling. We observed potent antitumor activity in vitro and in vivo in large panels of patient-derived xenograft models representing various solid cancers. The results of our preclinical studies provided the basis for an ongoing clinical trial exploring the activity of HexaBody-DR5/DR5 (GEN1029) in patients with malignant solid tumors.

Detection of Barrett's oesophagus through exhaled breath using an electronic nose device

Timely detection of oesophageal adenocarcinoma (OAC) and even more so its precursor Barrett's oesophagus (BO) could contribute to decrease OAC incidence and mortality. An accurate, minimally-invasive screening method for BO for widespread use is currently not available. In a proof-of-principle study in 402 patients, we developed and cross-validated a BO prediction model using volatile organic compounds (VOCs) analysis with an electronic nose device. This electronic nose was able to distinguish between patients with and without BO with good diagnostic accuracy (sensitivity 91% specificity 74%) and seemed to be independent of proton pump inhibitor use, the presence of hiatal hernia, and reflux. This technique may enable an efficient, well-tolerated, and sensitive and specific screening method to select high-risk individuals to undergo upper endoscopy.

DuoBody-CD3xCD20 induces potent T-cell-mediated killing of malignant B cells in preclinical models and provides opportunities for subcutaneous dosing

Background

DuoBody®-CD3xCD20 (GEN3013) is a full-length human IgG1 bispecific antibody (bsAb) recognizing CD3 and CD20, generated by controlled Fab-arm exchange. Its Fc domain was silenced by introduction of mutations L234F L235E D265A.

Methods

T-cell activation and T-cell-mediated cytotoxicity were measured by flow cytometry following co-culture with tumour cells. Anti-tumour activity of DuoBody-CD3xCD20 was assessed in humanized mouse models in vivo. Non-clinical safety studies were performed in cynomolgus monkeys.

Findings

DuoBody-CD3xCD20 induced highly potent T-cell activation and T-cell-mediated cytotoxicity towards malignant B cells in vitro. Comparison of DuoBody-CD3xCD20 to CD3 bsAb targeting alternative B-cell antigens, or to CD3xCD20 bsAb generated using alternative CD20 Ab, emphasized its exceptional potency. In vitro comparison with other CD3xCD20 bsAb in clinical development showed that DuoBody-CD3xCD20 was significantly more potent than three other bsAb with single CD3 and CD20 binding regions and equally potent as a bsAb with a single CD3 and two CD20 binding regions. DuoBody-CD3xCD20 showed promising anti-tumour activity in vivo, also in the presence of excess levels of a CD20 Ab that competes for binding. In cynomolgus monkeys, DuoBody-CD3xCD20 demonstrated profound and long-lasting B-cell depletion from peripheral blood and lymphoid organs, which was comparable after subcutaneous and intravenous administration. Peak plasma levels of DuoBody-CD3xCD20 were lower and delayed after subcutaneous administration, which was associated with a reduction in plasma cytokine levels compared to intravenous administration, while bioavailability was comparable.

Interpretation

Based on these preclinical studies, a clinical trial was initiated to assess the clinical safety of subcutaneous DuoBody-CD3xCD20 in patients with B-cell malignancies.

Funding

Genmab

Satellite cells maintain regenerative capacity but fail to repair disease-associated muscle damage in mice with Pompe disease

Pompe disease is a metabolic myopathy that is caused by glycogen accumulation as a result of deficiency of the lysosomal enzyme acid alpha glucosidase (GAA). Previously, we showed that adult muscle stem cells termed satellite cells are present at normal levels in muscle from patients with Pompe disease, but that these are insufficiently activated to repair the severe muscle pathology. Here we characterized the muscle regenerative response during disease progression in a mouse model of Pompe disease and investigated the intrinsic capacity of Gaa^-/- satellite cells to regenerate muscle damage. Gaa^-/- mice showed progressive muscle pathology from 15 weeks of age as reflected by increased lysosomal size, decreased fiber diameter and reduced muscle wet weight. Only during the first 15 weeks of life but not thereafter, we detected a gradual increase in centrally nucleated fibers and proliferating satellite cells in Gaa^-/- muscle, indicating a mild regenerative response. The levels of Pax7-positive satellite cells were increased in Gaa^-/- mice at all ages, most likely as result of enhanced satellite cell activation in young Gaa^-/- animals. Surprisingly, both young and old Gaa^-/- mice regenerated experimentally-induced muscle injury efficiently as judged by rapid satellite cell activation and complete restoration of muscle histology. In response to serial injury, Gaa^-/- mice also regenerated muscle efficiently and maintained the satellite cell pool. These findings suggest that, similar to human patients, Gaa^-/- mice have insufficient satellite cell activation and muscle regeneration during disease progression. The initial endogenous satellite cell response in Gaa^-/- mice may contribute to the delayed onset of muscle wasting compared to human patients. The rapid and efficient regeneration after experimental muscle injury suggest that Gaa^-/- satellite cells are functional stem cells, opening avenues for developing muscle regenerative therapies for Pompe disease.