Predicting tumor killing and T-cell activation by T-Cell Bispecific antibodies as a function of target expression: combining in vitro experiments with systems modeling

2020 ◽  
pp. molcanther.0269.2020
Author(s):  
Arthur J Van De Vyver ◽  
Tina Weinzierl ◽  
Miro J Eigenmann ◽  
Nicolas Frances ◽  
Sylvia Herter ◽  
...  
Cancers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 4596
Author(s):  
Joseph Kauer ◽  
Fabian Vogt ◽  
Ilona Hagelstein ◽  
Sebastian Hörner ◽  
Melanie Märklin ◽  
...  

T cell-recruiting bispecific antibodies (bsAbs) are successfully used for the treatment of cancer. However, effective treatment with bsAbs is so far hampered by severe side effects, i.e., potentially life-threatening cytokine release syndrome. Off-target T cell activation due to binding of bispecific CD3 antibodies to T cells in the absence of target cells may contribute to excessive cytokine release. We report here, in an in vitro setting, that off-target T cell activation is induced by bsAbs with high CD3 binding affinity and increased by endothelial- or lymphoid cells that act as stimulating bystander cells. Blocking antibodies directed against the adhesion molecules CD18/CD54 or CD2/CD58 markedly reduced this type of off-target T cell activation. CD18 blockade—in contrast to CD2—did not affect the therapeutic activity of various bsAbs. Since CD18 antibodies have been shown to be safely applicable in patients, blockade of this integrin holds promise as a potential target for the prevention of unwanted off-target T cell activation and allows the application of truly effective bsAb doses.


1995 ◽  
Vol 182 (1) ◽  
pp. 5-13 ◽  
Author(s):  
P Stumbles ◽  
D Mason

In vitro experiments using purified rat CD4+ T cells in primary and secondary mixed leukocyte cultures (MLC) have been carried out to explore the mechanism of inhibition of cell-mediated autoimmune disease in the rat by a nondepleting monoclonal antibody (mAb) to CD4. Previous work has shown that W3/25, a mouse anti-rat CD4 mAb of immunoglobulin G1 isotype, completely prevents the development of the paralysis associated with experimental allergic encephalomyelitis (EAE) in Lewis rats, but does so without eliminating the encephalitogenic T cells. The in vitro experiments described in this study have shown that when CD4+ T cells were activated in the presence of the anti-CD4 mAb in a primary MLC, the synthesis of interferon (IFN) gamma, but not interleukin (IL) 2, was completely inhibited. After secondary stimulation, now in the absence of the mAb, the synthesis of IL-4 and IL-13 mRNA was greatly enhanced compared with that observed from CD4+ T cells derived from primary cultures in which the mAb was omitted. As IL-4 and IL-13 are known to antagonize cell-mediated immune reactions, and as EAE is cell-mediated disease, the data suggest that the W3/25 mAb controls EAE by modifying the cytokine repertoire of T cells that respond to the encephalitogen. The capacity for the mAb to suppress IFN-gamma synthesis provides, in part, an explanation for this change in cytokine production. These findings are discussed in terms of what is known of the factors that determine which cytokine genes are expressed on T cell activation. Possible implications for the evolution of T cell responses in human immunodeficiency virus infection are also discussed.


2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 8017-8017 ◽  
Author(s):  
Ben Buelow ◽  
Duy Pham ◽  
Starlynn Clarke ◽  
Shelley Force Aldred ◽  
Kevin Dang ◽  
...  

8017 Background: Although BCMA is a plasma cell specific surface molecule attractive as an antibody target in multiple myeloma, its scarcity on the cell surface may limit the efficacy of a conventional antibody. T-cell engaging bispecific antibody approaches are highly efficacious and are particularly well suited for a membrane target with limited expression, such as BCMA. Teneobio has developed a multivalent antibody platform based on modular human VH domains, which allowed us to build T cell engaging bispecific antibodies with low and high T cell agonistic activities. Methods: UniRats were immunized with either CD3 or BCMA antigens and antigen-specific UniAbs were identified by antibody repertoire sequencing and high-throughput gene assembly, expression, and screening. High affinity binding VH sequences were selected using recombinant proteins and cells. In vitro efficacy studies included T-cell activation by cytokine- and tumor cell kill by calcein-release assays. In vivo efficacy of the molecules was evaluated in NSG mice harboring myeloma cells and human PBMCs. Results: BCMA-specific UniAbs bound plasma cells with high affinities (100-700pM) and cross-reacted with cynomolgus plasma cells. Strong and weak T cell agonists were identified that bound human T cells with high and low affinities respectively and cross-reacted with cynomolgus T cells. T cell engaging bispecifics with a strong (H929 cytotoxicity:EC50=27pM) and a weak T cell activating arm (H929 cytotoxicity: EC50=1170pM) demonstrated T-cell activation and tumor-cell cytotoxicity in vitro; bispecifics with a weak CD3 engaging arm showed markedly reduced cytokine production even at doses saturating for cytotoxicity. In viv o, BCMAxCD3 bispecific antibodies reduced tumor load and increased survival when co-administered with human PBMCs as compared to controls. Conclusions: Our results suggest that T cell engaging bispecifics with low-affinity anti-CD3 arms could be preferred for the treatment of Multiple Myeloma.


Biomolecules ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 399
Author(s):  
Aerin Yoon ◽  
Shinai Lee ◽  
Sua Lee ◽  
Sojung Lim ◽  
Yong-Yea Park ◽  
...  

As mesothelin is overexpressed in various types of cancer, it is an attractive target for therapeutic antibodies. T-cell bispecific antibodies bind to target cells and engage T cells via binding to CD3, resulting in target cell killing by T-cell activation. However, the affinity of the CD3-binding arm may influence CD3-mediated plasma clearance or antibody trapping in T-cell-containing tissues. This may then affect the biodistribution of bispecific antibodies. In this study, we used scFab and knob-into-hole technologies to construct novel IgG-based 1 + 1 MG1122-A and 2 + 1 MG1122-B bispecific antibodies against mesothelin and CD3ε. MG1122-B was designed to be bivalent to mesothelin and monovalent to CD3ε, using a 2 + 1 head-to-tail format. Activities of the two antibodies were evaluated in mesothelin-positive tumor cells in vitro and xenograft models in vivo. Although both antibodies exhibited target cell killing efficacy and produced regression of xenograft tumors with CD8+ T-cell infiltration, the antitumor efficacy of MG1122-B was significantly higher. MG1122-B may improve tumor targeting because of its bivalency for tumor antigen. It may also reduce systemic toxicity by limiting the activation of circulating T cells. Thus, MG1122-B may be useful for treating mesothelin-positive solid tumors.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A739-A739
Author(s):  
Michael Hedvat ◽  
Veronica Zeng ◽  
Juan Diaz ◽  
Christine Bonzon ◽  
Kendra Avery ◽  
...  

BackgroundT cells in the tumor micro-environment require TCR/MHC engagement and co-stimulatory receptor engagement to achieve complete activation. Solid tumors often lack expression of CD28 ligands, so we hypothesized that activation of CD28 signaling could be beneficial in solid tumors. We designed tumor-associated-antigen (TAA) x CD28 bispecific antibodies that conditionally costimulate CD28 only in the presence of TAA and TCR engagement. Clinical application of this class of antibodies has potential to enhance activity of either anti-PD(L)1 antibodies or TAA x CD3 T cell engagers.MethodsWe designed a stability and affinity optimized anti-CD28 antibody that can be paired with TAA of choice to engage CD28 monovalently using Xencor’s XmAb 2+1 and 1+1 platforms. In vitro T cell activation with these bispecifics was measured by T cell proliferation, cytokine production, and cytotoxicity, in co-cultures of human cancer cell lines mixed with primary human CD3-stimulated T cells. In vitro activity was validated in a CMV recall assay measuring CMV+ T cell proliferation of CMV+ PBMC co-cultured with cancer cell lines ectopically treated with pp65-derived NLV-peptide. In vivo anti-tumor and T cell proliferative activity of B7H3 x CD28 bispecific antibodies were determined in tumor-bearing huPBMC-NSG mice treated simultaneously with TAA x CD3 bispecific antibody. In vivo activity of PDL1 x CD28 antibodies was determined with hCD28 KI mice inoculated with MC38 tumors expressing hPDL1-antigen. Finally, safety and tolerability of B7H3 x CD28 and PDL1 x CD28 was determined in cynomolgus monkeys.ResultsB7H3 x CD28 and PDL1 x CD28 antibodies enhanced T cell degranulation, cytokine secretion, and cancer cell cytotoxicity in concert with CD3 stimulation only in the presence of target antigen. B7H3 x CD28, alone or in combination with anti-PD1 antibody, enhanced proliferation of CMV+ T cells recognizing cancer cells loaded with pp65-derived NLV peptide. PDL1 x CD28 also enhanced CMV+ cell expansion but did not synergize with anti-PD1 antibody treatment. B7H3 x CD28 significantly enhanced in vivo anti-tumor activity of TAA x CD3 antibodies while also promoting greater T cell expansion. In hCD28 mice inoculated with MC38 tumors expressing hPDL1, PDL1 x CD28 antibody inhibited tumor growth greater than an anti-PDL1 antibody alone. B7H3 x CD28 and PDL1 x CD28 were well tolerated in cynomolgus monkeys.ConclusionsB7H3 x CD28 and PDL1 x CD28 bispecific antibodies show promising anti-tumor activity and warrant further development.


2017 ◽  
Author(s):  
Junpeng Qi ◽  
Xiuling Li ◽  
Haiyong Peng ◽  
HaJeung Park ◽  
Christoph Rader

AbstractT-cell engaging bispecific antibodies present a promising strategy for cancer immunotherapy and numerous bispecific formats have been developed for retargeting cytolytic T cells toward tumor cells. To explore the therapeutic utility of T-cell engaging bispecific antibodies targeting the receptor tyrosine kinase ROR1, which is expressed by tumor cells of various hematologic and solid malignancies, we used a bispecific ROR1 × CD3 scFv-Fc format based on a heterodimeric and aglycosylated Fc domain designed for extended circulatory half-life and diminished systemic T-cell activation. A diverse panel of ROR1-targeting scFv derived from immune and naïve rabbit antibody repertoires was compared in this bispecific format for target-dependent T-cell recruitment and activation. A ROR1-targeting scFv with a membrane-proximal epitope, R11, revealed potent and selective antitumor activity in vitro and in vivo and emerged as a prime candidate for further preclinical and clinical studies. To elucidate the precise location and engagement of this membrane-proximal epitope, which is conserved between human and mouse ROR1, the three-dimensional structure of scFv R11 in complex with the kringle domain of ROR1 was determined by X-ray crystallography at 1.6-Å resolution.


2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A287-A287
Author(s):  
Xavier Chauchet ◽  
Elise Pernarrieta ◽  
Nicolas Bosson ◽  
Sébastien Calloud ◽  
Louis Hellequin ◽  
...  

BackgroundPD-1/PD-L1 blockade can significantly improve survival across many types of cancer, but only in a minority of patients. To broaden its therapeutic efficacy, several combination partners are now being evaluated together with PD-1/PD-L1 blockade. Agents blocking CD47/SIRPα innate immune checkpoint are one such example, and co-targeting PD-1/PD-L1 and CD47 with monoclonal antibody (mAb) combinations showed increased antitumor responses in preclinical studies. However, CD47 mAbs are hindered by ubiquitous CD47 expression leading to rapid target-mediated clearance and safety concerns. Consequently, dual-targeting CD47xPD-L1 bispecific antibodies (bsAbs) enabling preferential inhibition of CD47 on PD-L1-positive cells are being tested as an alternative approach. We compare here two distinct bsAbs, based on a common PD-L1 antibody arm, with differing FcgR-enabling effector functions and CD47-binding arm affinities.MethodsAn array of fully human bsAbs associating a high affinity PD-L1 arm to CD47 arms with varying affinities were generated using the κλ-body platform.1 CD47xPD-L1 bsAbs of human IgG1 isotype (CD47 low affinities) or IgG4 isotype (CD47 high affinities) were screened in various binding assays (including to red blood cells (RBC)) and in receptor-blocking assays, and then tested for their Fc-mediated killing and T-cell activation activity (SEA-stimulated PBMC assay). Selected molecules were evaluated in vivo.ResultsBoth bsAb approaches demonstrated strong blockade of PD-1/PD-L1 interaction and significantly enhanced T-cell activation in vitro. CD47lowxPD-L1 IgG1 bsAbs did not bind to RBC and showed PD-L1-guided inhibition of CD47. ADCP and ADCC experiments with a panel of tumor cell lines expressing various target levels showed superior killing activity with CD47lowxPD-L1 IgG1 bsAbs as compared to the anti-PD-L1 IgG1 mAb, avelumab. On the other hand, CD47highxPD-L1 IgG4 bsAbs showed residual RBC binding and PD-L1-independent blocking of CD47/SIRPα. These CD47high IgG4 bsAbs were able to enhance the anti-tumor activity of anti-tumor-associated antigen (TAA) mAbs in vitro (phagocytosis), and in vivo (Raji lymphoma xenograft model). In addition, anti-tumor activity of mouse CD47xPD-L1 bsAbs in a syngeneic MC38 colon carcinoma model was demonstrated.ConclusionsWith the objective of finding the optimal CD47xPD-L1 bsAb design, two approaches targeting CD47 and PD-L1 inhibition were tested. Both the CD47lowxPD-L1 IgG1 bsAbs and CD47highxPD-L1 IgG4 bsAbs were able to mediate enhanced antitumor responses, the former as a standalone treatment, the latter in conjunction with an anti-TAA mAb. To further characterize the CD47lowxPD-L1 and CD47highxPD-L1 bsAbs, lead candidates will be tested in PK and tolerability studies in non-human primates.ReferencesFischer N, Elson G, Magistrelli G, Dheilly E, Fouque N, Laurendon A, et al. Exploiting light chains for the scalable generation and platform purification of native human bispecific IgG. Nat Commun 2015 May;6(1):6113.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lauric Haber ◽  
Kara Olson ◽  
Marcus P. Kelly ◽  
Alison Crawford ◽  
David J. DiLillo ◽  
...  

AbstractT-cell-redirecting bispecific antibodies have emerged as a new class of therapeutic agents designed to simultaneously bind to T cells via CD3 and to tumor cells via tumor-cell-specific antigens (TSA), inducing T-cell-mediated killing of tumor cells. The promising preclinical and clinical efficacy of TSAxCD3 antibodies is often accompanied by toxicities such as cytokine release syndrome due to T-cell activation. How the efficacy and toxicity profile of the TSAxCD3 bispecific antibodies depends on the binding affinity to CD3 remains unclear. Here, we evaluate bispecific antibodies that were engineered to have a range of CD3 affinities, while retaining the same binding affinity for the selected tumor antigen. These agents were tested for their ability to kill tumor cells in vitro, and their biodistribution, serum half-life, and anti-tumor activity in vivo. Remarkably, by altering the binding affinity for CD3 alone, we can generate bispecific antibodies that maintain potent killing of TSA + tumor cells but display differential patterns of cytokine release, pharmacokinetics, and biodistribution. Therefore, tuning CD3 affinity is a promising method to improve the therapeutic index of T-cell-engaging bispecific antibodies.


2021 ◽  
Vol 22 (10) ◽  
pp. 5394
Author(s):  
Tomas Lidak ◽  
Nikol Baloghova ◽  
Vladimir Korinek ◽  
Radislav Sedlacek ◽  
Jana Balounova ◽  
...  

Multisubunit cullin-RING ubiquitin ligase 4 (CRL4)-DCAF12 recognizes the C-terminal degron containing acidic amino acid residues. However, its physiological roles and substrates are largely unknown. Purification of CRL4-DCAF12 complexes revealed a wide range of potential substrates, including MOV10, an “ancient” RNA-induced silencing complex (RISC) complex RNA helicase. We show that DCAF12 controls the MOV10 protein level via its C-terminal motif in a proteasome- and CRL-dependent manner. Next, we generated Dcaf12 knockout mice and demonstrated that the DCAF12-mediated degradation of MOV10 is conserved in mice and humans. Detailed analysis of Dcaf12-deficient mice revealed that their testes produce fewer mature sperms, phenotype accompanied by elevated MOV10 and imbalance in meiotic markers SCP3 and γ-H2AX. Additionally, the percentages of splenic CD4+ T and natural killer T (NKT) cell populations were significantly altered. In vitro, activated Dcaf12-deficient T cells displayed inappropriately stabilized MOV10 and increased levels of activated caspases. In summary, we identified MOV10 as a novel substrate of CRL4-DCAF12 and demonstrated the biological relevance of the DCAF12-MOV10 pathway in spermatogenesis and T cell activation.


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