Lynn Dorothy Poulton

A novel class of anti-IL-12p40 antibodies: potent neutralization via inhibition of IL-12-IL-12Rβ2 and IL-23-IL-23R.

While current therapeutic antibodies bind to IL-12 and IL-23 and inhibit their binding to IL-12Rβ1, we describe a novel antibody, termed 6F6, that binds to IL-12 and IL-23 and inhibits the interaction of IL-12 and IL-23 with their cognate signalling receptors IL-12Rβ2 and IL23R. This antibody does not affect the natural inhibition of the IL-12/23 pathway by the antagonists monomeric IL-12p40 and IL-12p80, which suggests that a dual antagonist system is possible. We have mapped the epitope of 6F6 to domain 3 of the p40 chain common to IL-12 and IL-23 and demonstrate that an antibody bound to this epitope is sufficient to inhibit engagement of the signalling receptors. Antibodies with this unique mechanism of inhibition are potent inhibitors of IL-12 induced IFN-γ production and IL-23 induced IL-17 production in vitro, and in an in vivo model of psoriasis, treatment with a humanized variant of this antibody, h6F6, reduced the inflammatory response, resulting in decreased epidermal hyperplasia. We believe that this new class of IL-12/23 neutralising antibodies has the potential to provide improved potency and efficacy as anti-inflammatory agents, particularly in diseases characterized by an overproduction of IL-12.

Potent neutralizing anti-CD1d antibody reduces lung cytokine release in primate asthma model.

CD1d is a receptor on antigen-presenting cells involved in triggering cell populations, particularly natural killer T (NKT) cells, to release high levels of cytokines. NKT cells are implicated in asthma pathology and blockade of the CD1d/NKT cell pathway may have therapeutic potential. We developed a potent anti-human CD1d antibody (NIB.2) that possesses high affinity for human and cynomolgus macaque CD1d (KD ∼100 pM) and strong neutralizing activity in human primary cell-based assays (IC50 typically <100 pM). By epitope mapping experiments, we showed that NIB.2 binds to CD1d in close proximity to the interface of CD1d and the Type 1 NKT cell receptor β-chain. Together with data showing that NIB.2 inhibited stimulation via CD1d loaded with different glycolipids, this supports a mechanism whereby NIB.2 inhibits NKT cell activation by inhibiting Type 1 NKT cell receptor β-chain interactions with CD1d, independent of the lipid antigen in the CD1d antigen-binding cleft. The strong in vitro potency of NIB.2 was reflected in vivo in an Ascaris suum cynomolgus macaque asthma model. Compared with vehicle control, NIB.2 treatment significantly reduced bronchoalveolar lavage (BAL) levels of Ascaris-induced cytokines IL-5, IL-8 and IL-1 receptor antagonist, and significantly reduced baseline levels of GM-CSF, IL-6, IL-15, IL-12/23p40, MIP-1α, MIP-1β, and VEGF. At a cellular population level NIB.2 also reduced numbers of BAL lymphocytes and macrophages, and blood eosinophils and basophils. We demonstrate that anti-CD1d antibody blockade of the CD1d/NKT pathway modulates inflammatory parameters in vivo in a primate inflammation model, with therapeutic potential for diseases where the local cytokine milieu is critical.

An anti-TL1A antibody for the treatment of asthma and inflammatory bowel disease

ABSTRACT TL1A is an attractive therapeutic target for the treatment of mucosal inflammation associated with inflammatory bowel disease (IBD) and asthma. Blockade of the TL1A pathway has been shown to reduce inflammatory responses while leaving baseline immunity intact, and to be beneficial in animal models of colitis and asthma. Given the therapeutic potential of blocking this pathway in IBD and asthma, we developed C03V, a human antibody that binds with high affinity to soluble and membrane-bound TL1A. In an assay measuring apoptosis induced by exogenous TL1A, C03V was 43-fold more potent than the next most potent anti-TL1A antibody analyzed. C03V also potently inhibited endogenous TL1A activity in a primary cell-based assay. This potency was linked to the C03V-binding epitope on TL1A, encompassing the residue R32. This residue is critical for the binding of TL1A to its signaling receptor DR3 but not to its decoy receptor DcR3, and explains why C03V inhibited TL1A-DR3 binding to a much greater extent than TL1A-DcR3 binding. This characteristic may be advantageous to preserve some of the homeostatic functions of DcR3, such as TL1A antagonism. In colitis models, C03V significantly ameliorated microscopic, macroscopic and clinical aspects of disease pathology, and in an asthma model it significantly reduced airways inflammation. Notable in both types of disease model was the reduction in fibrosis observed after C03V treatment. C03V has the potential to address unmet medical needs in asthma and IBD.