HCAbs are efficiently generated from transgenic Harbour Mice where mouse VH loci were replaced with selected human VH genes, concurrent with the CH1 gene deletion. These HCAbs resemble camelid HCAbs in size and solubility, but have added advantages due to their human origin. HBM4003, a CTLA4 antagonist, will be reported to showcase Harbour's HCAb versatility as monospecific therapeutics. Furthermore, their use as natural building blocks for bispecific antibodies will be discussed.

Macromoltek has built proprietary computational technology for accurate & fast antibody design. Our technology allows us to go after difficult targets inaccessible by experimental methods, with a focus on speed to produce quick results for experimental testing. In this talk, we will present several case studies on a variety of projects and targets.

Diffuse Intrinsic Pontine Glioma (DIPG) is a universally fatal high-grade glioma of the brainstem that occurs in children. We have identified GD2 as overexpressed on DIPG and other gliomas bearing the H3K27M mutation. GD2 CAR T cells demonstrate potent activity against xenograft models of DIPG. Despite low level expression of GD2 on brain tissues, we did not observe on target, off tumor toxicity. We did observe toxicity in some models that appears to be due to the precarious neuroanatomical location of these tumors.

IL1RAP is a coreceptor for several cytokine receptors, such as the IL-1, IL-33 and IL-36 receptors, and is essential for signalling through these receptors. IL-1, IL-33 and IL-36 all mediate pro-inflammatory signalling and blocking of these signalling pathways with antibodies against IL1RAP have potential in autoimmune, inflammatory as well as in malignant diseases. An antibody against IL1RAP is currently in clinical development in oncology.

CAR T-cell therapy has emerged as an attractive component in the cancer treatment landscape. However, for most cancers we know little about what tumor antigens can be safely and effectively targeted. We previously studied mesothelin as a target for many cancers. In recent years, we have investigated cell surface glypicans including GPC3 and GPC2 as potential targets for treating liver cancer, childhood cancers (e.g. neuroblastoma) and other cancers.

We have identified GDF15 as a potent hormone for potentially treating diabetes and weight loss. GDF15 regulates food intake, energy expenditure and body weight in response to metabolic and toxin-induced stresses. In the course of pursuing its molecular mechanism, we have undertaken extensive biochemical, cell-based, and functional screenings, culminating in the discovery of GFRAL/RET as the cognate receptor for GDF15. By isolating GFRAL as the receptor for GDF15-induced anorexia and weight loss, we identify a mechanistic basis for the non-homeostatic regulation of neural circuitry by a peripheral signal associated with tissue damage and stress. Furthermore, we have co-crystalized GDF15 with its cognate receptor GFRAL to gain insight of detailed molecular interactions. We have then identified an array of antagonistic antibodies, including competitive, non-competitive and allosteric modulators. Co-crystal structures of antibodies with GFRAL further defined the nature of interactions of these modulators with GDF15 receptor; and this led us to have successfully generated antibodies intended for preventing weight loss in cancer cachexia. Presently GDF15 for treating diabetes and weight loss is in development by Merck through licensing, and antibody for GFRAL is in phase 1 clinical study by NGM.

ROR1 is a potential therapeutic target in both haematological and solid tumour immunotherapy. CARs with binding domains isolated from either immunised animals or a human phage display library were compared. We demonstrate that binder origin and biophysical properties influence the functional performance of CARs.

We are developing a therapeutic antibody for Inflammation and fibrosis targeting LRP6, a master regulator of tissue repair. LRP6 is a key co-receptor for canonical Wnt signaling that plays role in orchestrating wound healing and tissue repair.  Because the LRP6 receptor has a large extracellular region with two separate ligand binding domains, successfully targeting LRP6 signaling requires novel antibody engineering.

Challenges in current cancer immunotherapy include increasing response rates and decreasing toxicity. We have developed tumor-selective oncolytic vectors for delivery of immunomodulators to avoid systemic exposure and mitigate toxicity. Furthermore, vector-mediated oncolysis serves as an in situ tumor vaccine, inducing synergistic anti-tumor immune responses. This talk highlights the versatility of our vector system and avenues for clinical translation.

Fibrosis is a serious complication of injuries to tissues and organs. The formation of collagen-rich deposits is the ultimate problem that affects functions of fibrotic tissues. This presentation identifies collagen fibrillogenesis as an anti-fibrotic target. The antibody-based inhibition of collagen fibril formation demonstrates efficacy in relevant models of fibrosis

CAR-T cell therapies to membrane antigens have been highly successful in hematological but not in solid tumors. Addressing intracellular pMHC targets only possible through T-cell receptor (TCR)-based approaches is thought to be a key element to successful treatment of solid cancers. Using the XPRESIDENT platform to discover and validate novel targets and TCRs, we will be reporting on clinical trials using endogenous and gene-engineered T cells in various solid cancers conducted at MD Anderson Cancer Center.

Integrin a11b1 is a receptor for fibrillar collagens with a central role in cell adhesion, collagen reorganization and tissue homeostasis. Work with animal models have revealed its role in tooth eruption and wound healing. More recent work has suggested its involvement in heart and skin fibrosis. It is suggested that novel a11b1- based tools (including monoclonal antibodies and transgenic mice), will be central to elucidating molecular mechanisms of tissue fibrosis.

NGS is accelerating the field of therapeutic antibody research. Scientists face a growing need for software that enables them to efficiently and accurately analyze their rapidly expanding data sets. Automating the screening, annotation and analysis of antibody sequences will free research scientists to spend less time managing data and more time focused on science - but what lies beyond as innovators start applying pattern recognition technologies to their data?

The generation of antibodies to therapeutic targets with high conservation between rodents and humans is a challenge.  Chickens are an ideal species to circumvent this because of their increased evolutionary distance from humans compared to rodents.  We present the most recent data from the OmniChicken, a transgenic animal with fully human VL and VH loci.  Here we describe the immune response and isolation of monoclonal antibodies from birds expressing V-lambda 1-44, the newest transgene in the OmniChicken portfolio.

Many physicochemical modifications can adversely impact the molecular integrity of biological molecules and cause nasty surprises further down the development pathway. With the latest bioanalytical technologies and in silico tools and databases, these liability sites can now be identified early, investigated and if needed, removed with decent throughput prior to lead selection. We present case studies where hidden liabilities were found and what interventions were necessary, warranting an early investment that may be more cost effective in the long run.

Oral delivery of biologics is still considered as the 'holy grail', however, very few products have reached the market. Intract has invented the Soteria® technology that involves targeted delivery of biologics to the colon - which utilises the clinically validated Phloral® coating - and protects the biologic from degradation in the colon where it can exert its therapeutic effect.

A case study will be shown for the affinity maturation of an anti-Cathepsin S antibody by rational library design followed by molecular docking of variants in a step-wise combinatorial fashion.

The best chance to find a low frequency hit is to capture a broad diversity of the

immune response. Single Cell Technology uses affinity-maturated B cells on a

platform that collects metadata per cell: binding activity against multiple screening

molecules is correlated with native VH and VL sequence pairs. Case studies from

antibody campaigns will be presented.

Examples of the convergence of protein-based biologics and cellular therapies into the modern-day field of immunotherapy include novel antibody formats, such as BiTEs and Fc-fragments; T- & NK-cell therapies, such as CAR and high affinity Fc receptor expression; and checkpoint modulation.  Although immunotherapies can be divergent in form (biologic, cellular or combination), a common need for first-in-class execution is sophisticated cell engineering.  Case studies highlighting the performance, flexibility and clinical-feasibility of MaxCyte cell engineering will be presented including:

• Engineering of novel protein formats for fine-tuning in vivo effector functions
• NK cell engineering for improved efficacy of approved mAb therapies
• PD-1 gene engineering to combat tumor immunosuppression

Sharon Beasley, Field Applications Scientist, MaxCyte

We have developed a technology to enable direct incorporation of multipass membrane proteins such as GPCRs and ion channels into the membrane of a mammalian virus. Antigen expressing virus can be readily purified and used for antibody selection. This method is rapid, does not require any detergents or refolding and produces properly folded protein that is necessary for antibody selection.

The Antibody Transport Vehicle (ATV) enables the delivery of large molecule therapeutics to the brain for the treatment of neurological diseases. The ATV platform contains an engineered Fc domain that binds the transferrin receptor and utilizes receptor-mediated transcytosis to cross the BBB. Transport in nonhuman primates was assessed by the inhibition of beta-secretase 1 (BACE1) in brain which was robustly inhibited by ATV:BACE1 leading to a sustained reduction in amyloid beta levels.

Although cytokines modulate immune responses, systemic administration necessitates high doses. With the use of cytokines fused to alpaca antibody fragments (VHHs) specific for PD-L1, systemic delivery of low doses led to intratumoral localization, allowing for therapeutic effects in pancreatic cancer models. Many tumors and tumor-infiltrating myeloid cells express PD-L1, rendering them potentially susceptible to this form of targeted immunotherapy.

N-terminally truncated and post-translationally modified Abeta peptides, pGlu-Abeta, are emerging targets for therapeutic approaches against Alzheimer's Disease (AD). In contrast to common anti-Abeta therapies, these antibodies are tailored approaches to clear highly neuro/synaptotoxic forms of soluble and aggregated Abeta, which are directly implicated with cognitive decline in AD patients. Here, we present the structural and functional analyses of pGlu-Abeta antibodies. The structural basis of target binding specificity, the humanization, de-immunization and effector function modifications of the lead therapeutic antibody, PBD-C06, will be presented.

Antikor has harnessed the tumor penetration and rapid clearance properties of single-chain Fvs to make them more effective and tolerated alternatives to ADCs. We will present data on our antibody discovery capabilities that can lead to a potentially new class of therapeutics of high-payload carrying FDCs for gastric cancer and beyond.

The strongest genetic factor for late-onset Alzheimer's disease is the apolipoprotein E4 (apoE4) allele with overwhelming evidence pointing to its pathogenic role in amyloid β (Aβ) aggregation and clearance. To test whether anti-human apoE antibodies decrease Aβ pathology in APOE4KIxAPPPS1-21 mice, we administered centrally and peripherally apoE antibodies that preferentially bind nonlipidated, aggregated apoE. We observed decreased amyloid accumulation that was dependent on Fcgamma receptor binding, demonstrating the therapeutic potential of targeting microglia to aggregated apoE species in Aβ plaques.

We present a novel ADC based on site-specific conjugation of a derivative of the anthracycline PNU-159682 using the transpeptidase Sortase A. The use of a non-cleavable peptide linker provides exquisite stability, whereas the anthracycline payload endows the ADC with superior potency combined with attractive immune-oncology properties intrinsic to this class of payloads. Validating data obtained in numerous PDX models, as well as in immunocompetent syngeneic models, will be presented.

Active or passive tau immunotherapies have advanced to eight clinical trials, although the mechanisms involved are not well defined. Some tau antibodies appear to work primarily extracellularly whereas others can also clear/neutralize tau intracellularly. Since most pathological tau is within neurons, such broadly acting antibodies are likely to be more efficacious than those that only work extracellularly. In addition, humanization can dramatically change antibody properties and thereby may affect their biodistribution and efficacy. Hence, those derivatives need to be re-examined thoroughly prior to clinical trials. These therapeutic studies have also led to the development of antibody fragments as imaging probes, which are more specific than the β-sheet dyes that are being tested in humans, and may then allow tailoring the immunotherapy to the most prominent pathological tau epitopes in each subject.

Immunotherapy of cancer with CD3-targeting bispecific antibodies (CD3 bsAb) is a very promising strategy, also for solid malignancies. Xenograft mouse models often fail to fully recapitulate the natural tumor microenvironment, and therefore we investigated the immunological consequences of CD3 bsAb therapy in fully immune-competent mouse tumor models.

Currently, there are no treatments available that stop or slow the progression of Huntington's Disease, Parkinson's Disease, and tauopathies. To solve this problem, our lab developed bifunctional intrabodies that targeted mutant huntingtin protein and α-synuclein to the proteasome for degradation via a PEST degron fusion. I am currently utilizing induced pluripotent stem cell (iPSC) disease modeling to validate candidate intrabodies for treatment of neurodegenerative disorders.

Recent advances in gene therapy for neurological diseases include several clinical trials of gene replacements, and further engineering of viral vectors capsids to allow targeted and/or systemic delivery. This approach is especially powerful for antibody fragments that have been engineered to function intracellularly as intrabodies, and it is also being applied more broadly for several neurodegenerative diseases.

Xencor has applied its XmAb bispecific technology platform to create multiple novel modalities for T cell derepression and activation. These include dual checkpoint inhibitors such as a PD1 x CTLA4 bispecific antibody, and a CTLA4 x LAG3 bispecific antibody that combines productively with anti-PD1 for triple checkpoint blockade. We have also discovered a highly active PD1 x ICOS bispecific antibody that productively combines checkpoint blockade and costimulation into a single molecule. Finally, we have utilized our heterodimeric Fc domain to create a novel long-acting and/or targeted IL15/IL15Ra-Fc format for immunotherapy.