Pub. date: 2008 | Online Pub. Date: May 22, 2008 | DOI: 10.4135/9781848605985 | Print ISBN: 9781847870483 | Online ISBN: 9781848605985 | Publisher:SAGE Publications LtdAbout this handbook
Chapter 34: Future of VLA-4 Antagonist Drugs and Implications for the Regulatory Process
Future of VLA-4 antagonist drugs and implications for the regulatory process Several companies have been investigating the potential of very late activation antigen-4 (VLA-4, also known as α4β1 integrin), located on the surface of T cells, as a drug target in a variety of inflammatory diseases. However, in March 2005, in response to difficulties with Biogen Idec and Elan's natalizumab (Tysabri, formerly Antegren) – a marketed monoclonal antibody (MAb) directed against this integrin – the FDA decided to place a clinical hold on another VLA-4 acting drug in clinical trials, and a second company voluntarily withdrew its VLA-4 drug from development while an investigation into the safety of this drug class is conducted. These safety concerns have affected drugs in development for the treatment of multiple sclerosis (MS), Crohn's disease (CD), asthma, and others. Natalizumab's regulatory journey shows how this promising new drug class has come to encounter difficulty. Prior ...