CHH 380 (chimeric anti-CD7 antibody, SDZ CHH 380) is a chimeric mouse/human monoclonal antibody which acts against the CD7 protein (a prime mediator of immunological responses) on the surface of activated T cells, thereby blocking their action. Novartis has discontinued development of CHH 380, but Celltech (UK), Genentech (USA), the Royal Free Hospital (UK) and Stanford University (USA) are developing the drug for the prevention/treatment of organ transplant rejection and rheumatoid arthritis. Development for use in transplant rejection is in phase III clinical trials in Canada, the UK and the USA. CHH 380 is available for licensing.