The Discovery, Engineering and Characterisation of a Highly Potent Anti-Human IL-13 Fab Fragment Designed for Administration by Inhalation

• Published in: Journal of molecular biology Vol. 425; no. 3; pp. 577 - 593
• Main Authors: Lightwood, Daniel, O'Dowd, Victoria, Carrington, Bruce, Veverka, Vaclav, Carr, Mark D., Tservistas, Markus, Henry, Alistair J., Smith, Bryan, Tyson, Kerry, Lamour, Sabrina, Sarkar, Kaushik, Turner, Alison, Lawson, Alastair D., Bourne, Tim, Gozzard, Neil, Palframan, Roger
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 08.02.2013
• Subjects: Administration, Inhalation; asthma; atomization; binding capacity; breathing; Epitope Mapping; Fab; fluorescent foci; genes; Humans; Immunoglobulin Fab Fragments - genetics; Immunoglobulin Fab Fragments - isolation & purification; Immunoglobulin Fab Fragments - pharmacology; immunoglobulin G; Immunologic Factors - genetics; Immunologic Factors - isolation & purification; Immunologic Factors - pharmacology; in vitro studies; inhalation; interleukin-13; Interleukin-13 - antagonists & inhibitors; intranasal administration; monoclonal antibody; neutralization; nuclear magnetic resonance spectroscopy; RT; IL; Fab; DLS; asthma; CHO; PBMC; HEK; SEC; HDM; CDR; 3D; inhalation; STAT; TGF; fluorescent foci; monoclonal antibody; HPLC
• ISSN: 0022-2836; 1089-8638
• DOI: 10.1016/j.jmb.2012.11.036

We describe the discovery, engineering and characterisation of a highly potent anti-human interleukin (IL)-13 Fab fragment designed for administration by inhalation. The lead candidate molecule was generated via a novel antibody discovery process, and the selected IgG variable region genes were successfully humanised and reformatted as a human IgG γ1 Fab fragment. Evaluation of the biophysical properties of a selection of humanised Fab fragments in a number of assays allowed us to select the molecule with the optimal stability profile. The resulting lead candidate, CA652.g2 Fab, was shown to have comparable activity to the parental IgG molecule in a range of in vitro assays and was highly stable. Following nebulisation using a mesh nebuliser, CA652.g2 Fab retained full binding affinity, functional neutralisation potency and structural integrity. Epitope mapping using solution nuclear magnetic resonance confirmed that the antibody bound to the region of human IL-13 implicated in the interaction with IL-13Rα1 and IL-13Rα2. The work described here resulted in the discovery and design of CA652.g2 human γ1 Fab, a highly stable and potent anti-IL-13 molecule suitable for delivery via inhalation. [Display omitted] ► Generation of a highly potent anti-IL-13 antibody designed for inhalation. ► Application of a novel antibody discovery platform. ► Biophysical profiling enabled selection of a robust and stable molecule. ► NMR enabled elucidation of the epitope and the mode of action of the lead candidate.