1. Celltech R&D Ltd., Granta Park, Great Abington, Cambridge, CB1 6GS, United Kingdom, Department of Medicinal Chemistry, Victorian College of Pharmacy, Monash University, 381 Royal Parade, Parkville, Australia, Centre for Molecular Design, University of Portsmouth, King Henry Building, King Henry I Street, Portsmouth, Hampshire, PO1 2DY, United Kingdom, and ChemQuest, Delamere House, 1 Royal Crescent, Sandown, Isle of Wight, PO36 8LZ, United Kingdom