A RAGE-Targeted Antibody-Drug Conjugate: Surface Plasmon Resonance as a Platform for Accelerating Effective ADC Design and Development.

Antibodies, antibody-like molecules, and therapeutics incorporating antibodies as a targeting moiety, such as antibody-drug conjugates, offer significant potential for the development of highly efficacious drugs against a wide range of disorders. Despite some success, truly harnessing the superior targeting properties of these molecules requires a platform from which to effectively identify the best candidates for drug development. To streamline the development of antibody-drug conjugates targeting gynecological cancers within our laboratory, we incorporated surface plasmon resonance analysis (Biacore™ T200) into our development toolkit. Antibodies, selected based on positive ELISA screens as suitable for development as antibody-drug conjugates, were evaluated using surface plasmon resonance to determine a wide range of characteristics including specificity, kinetics/affinity, the effect of linker binding, the impact of the drug to antibody ratio, and the effect of endosomal pH on antibody-antigen binding. Analysis revealed important kinetics data and information regarding the effect of conjugation and endosomal pH on our antibody candidates that correlated with cell toxicity and antibody internalization data. As well as explaining observations from cell-based assays regarding antibody-drug conjugate efficacies, these data also provide important information regarding intelligent antibody selection and antibody-drug conjugate design. This study demonstrates the application of surface plasmon resonance technology as a platform, where detailed information can be obtained, supporting the requirements for rapid and high-throughput screening that will enable enhanced antibody-drug conjugate development.

Antibody drug conjugates against the receptor for advanced glycation end products (RAGE), a novel therapeutic target in endometrial cancer.

BACKGROUND: The treatment of endometrial cancer (EC), the most common gynecological cancer, is currently hampered by the toxicity of current cytotoxic agents, meaning novel therapeutic approaches are urgently required. METHODS: A cohort of 161 patients was evaluated for the expression of the receptor for advanced glycation end products (RAGE) in endometrial tissues. The present study also incorporates a variety of in vitro methodologies within multiple cell lines to evaluate RAGE expression and antibody-drug conjugate efficacy, internalisation and intercellular trafficking. Additionally, we undertook in vivo bio-distribution and toxicity evaluation to determine the suitability of our chosen therapeutic approach, together with efficacy studies in a mouse xenograft model of disease. RESULTS: We have identified an association between over-expression of the receptor for advanced glycation end products (RAGE) and EC (H-score = Healthy: 0.46, SD 0.26; Type I EC: 2.67, SD 1.39; Type II EC: 2.20, SD 1.34; ANOVA, p < 0.0001). Furthermore, increased expression was negatively correlated with patient survival (Spearman's Rank Order Correlation: ρ = - 0.3914, p < 0.05). To exploit this association, we developed novel RAGE-targeting antibody drug conjugates (ADC) and demonstrated the efficacy of this approach. RAGE-targeting ADCs were up to 100-fold more efficacious in EC cells compared to non-malignant cells and up to 200-fold more cytotoxic than drug treatment alone. Additionally, RAGE-targeting ADCs were not toxic in an in vivo pre-clinical mouse model, and significantly reduced tumour growth in a xenograft mouse model of disease. CONCLUSIONS: These data, together with important design considerations implied by the present study, suggest RAGE-ADCs could be translated to novel therapeutics for EC patients.

Variation in concentration of prion protein in the peripheral blood of patients with variant and sporadic Creutzfeldt-Jakob disease detected by dissociation enhanced lanthanide fluoroimmunoassay and flow cytometry.

BACKGROUND: A highly sensitive dissociation-enhanced lanthanide fluoroimmunoassay (DELFIA) and flow cytometry techniques have previously been developed and employed to characterize soluble cellular prion protein (PrP(c)) expression in whole blood and separated components from healthy adult blood donors. No previous studies with these techniques have evaluated the concentration and expression of PrP in the blood of patients with variant Creutzfeldt-Jakob disease (vCJD). STUDY DESIGN AND METHODS: For blood from vCJD patients, sporadic CJD (sCJD) patients, non-CJD neurological controls, and healthy adults, PrP(c) was measured by DELFIA and cell-associated PrP was measured by flow cytometry. RESULTS: DELFIA analysis identified a significant reduction in the concentration of PrP(c) in the whole blood of vCJD (p = 0.012) and non-CJD neurological patients (p = 0.0004) compared with healthy adults. A significant elevation was found in plasma PrP(c) in sCJD patients compared with healthy adult (p = 0.022) and neurological controls (p = 0.050). Flow cytometry found no significant differences between groups in expression of PrP on platelets and lymphocytes, nor in sensitivity of cellular PrP to proteinase K. Neurological controls show significantly less PrP on red cells than healthy adults. CONCLUSION: There are differences in free and cell-associated PrP found in blood of CJD patients and control groups, some of which might be useful with other tests in disease profiling as an aid to diagnoses.