Over the last decade, various new therapies have been developed to promote anti-tumor immunity. Despite interesting clinical results in hematological malignancies, the development of bispecific killer cell-engager antibody formats directed against tumor cells and stimulating anti-tumor T cell immunity has proved challenging, mostly due to toxicity problems. We report here the generation of trifunctional natural killer (NK) cell engagers (NKCEs), targeting two activating receptors, NKp46 and CD16, on NK cells, and a tumor antigen on cancer cells. Trifunctional NKCEs were more potent in vitro than clinical therapeutic antibodies targeting the same tumor antigen. They had similar in vivo pharmacokinetics to full IgG antibodies and no off-target effects, and efficiently controlled tumor growth in mouse models of solid and invasive tumors. Trifunctional NKCEs thus constitute a new generation of molecules for fighting cancer.

The presentation will provide an overview and examples of our bsAb molecules, including examples of novel exploratory approaches. Important aspects that will be covered also include high-throughput technologies to identify optimal binder-format combinations to elicit desired bsAb functionalities, and examples that demonstrate its relevance. 

Hybridoma & phage display technologies dominate the antibody discovery space, but there is a growing interest in functionally interrogating the b-cell repertoire. We’re presenting results from our REpAb technology which leverages NGS & MS antibody protein sequencing technologies to de novo sequence the most functionally abundant antibodies in polyclonal sera.

We report an approach for a personalized cancer therapy by generating patient-specific binders against the B-cell receptor of lymphomas. To this end, we established a platform for rapid yeast surface display identification of shark-derived vNAR antibody domains from semisynthetic libraries specifically targeting lymphoma cells. Several formats of vNAR bispecifics and ADCs were evaluated aimed at widening the therapeutic window for B-cell lymphoma therapy.

Many cancer therapies don’t involve the innate immune system. Affimed’s ROCK platform is designed to develop innate cell engagers (ICEs) for various indications. All ICEs bear a CD16A-binding paratope, which triggers tumor cell killing through activating NK cells and macrophages.The modular ROCK platform allows to customize ICEs with respect to tumor target, affinity, pharmacokinetics, and the plethora of molecules in our pipeline has demonstrated rapid and predictable engineering capabilities.

ImmTAC molecules are T cell-engaging bispecifics that target tumor-specific peptide-HLA. To optimise ImmTAC design, we assessed the impact on potency and specificity of combinatorially varying the affinity for target and CD3 over a 1000-fold range. Consistent with kinetic models of T cell activation, we found that when both targeting and effector arms have very high affinity this negatively affects activity, and that modifying the CD3 off-rate can influence both potency and specificity.

Bispecific biologics such as dual variable domain immunoglobulins (DVD-Igs) offer new opportunities for innovative tissue/disease targeted therapies and have permitted the exploration of tissue specific and disease tissue specific targeting of biologics. We will describe preclinical examples of tissue targeting in normal and disease in vivo models as part of a new generation of locally acting “regio-specific” biologics therapies.

Multispecific antibodies find increasing interest for therapeutic applications. With our newly designed antibody platform technologies we are able to generate Ig-like molecules of varying valency, specificity, geometry, flexibility, and size. Data will be presented demonstrating the effects of these parameters on the efficacy of bispecific T cell engagers.

While immune checkpoint blockade leads to potent antitumor efficacy, it also leads to immune-related adverse events in cancer patients. We developed an anti-CTLA4 DVD-Ig possessing an outer tumor-specific antigen-binding domain engineered to shield the inner anti-CTLA4-binding domain until the outer domain was cleaved by MT-SP1 present in the tumor microenvironment. Thus, our tumor-conditional anti-CTLA4 DVD provides an avenue for uncoupling antitumor efficacy from immunotherapy-induced toxicities.

Cancer immunotherapy, such as PD1/PD-L1 inhibitors, have demonstrated therapeutic efficacy across a range of human cancers. Extending this benefit to a greater number of patients, however, will require a better understanding of how these therapies affect anti-tumor immunity, especially in exisiting immunity in the tumor microenvironment. I will discuss how to harness the power of immunity using bispecific antibodies that could create new biology.

T-cell bispecific antibodies (BsAbs) couple T-lymphocytes against tumor cells, inducing their destruction. We have recently identified 3 features of the IgG-[L]-scFv BsAb format which impacted their function: i) spatial configuration (cis-configuration), ii) interdomain spacing (one Ig-domain) and iii) valency (two cis-modules). When combined these parameters enhanced cytotoxicity, cytokine release and anti-tumor responses. These findings highlight the importance of BsAb design and provide guidelines for improving BsAb function.

Due to adaptiveness of oncogenic networks, tumors driven by hyperactivated RTK receptors readily develop resistance against targeted therapies. We developed multivalent DARPin and IgG chimeric agents devoid of toxic payloads, which achieve their tumoricidal activity by trapping tumor-driving receptor tyrosine kinases in inactive conformations and/or supramolecular assemblies. Using analogous construction scheme, we built a novel platform for tumor RTK fingerprinting aimed at identification of prospective therapeutic leads or truly synergistic combination therapies.