Avidex Announces Rhudex® Successfully Completes Phase I Studies In Rheumatoid Arthritis

Company’s Lead Product to Start Patient Studies in Mid 2006

Oxford (UK), Avidex, the UK based Biopharmaceutical company, today announces at BioSquare 2006 in Geneva, Switzerland that its lead product candidate, RhuDex®, has successfully completed two Phase I studies looking at safety, tolerability and pharmacokinetics in normal, healthy volunteers.

RhuDex® is a small molecule, orally active, T cell co-stimulation modulator with a similar mode of action to the recently approved biological Orencia ® (BMS). It is principally being investigated in rheumatoid arthritis (RA) but may have applications in a broad range of autoimmune diseases. RhuDex® potentially offers a novel approach in the treatment of RA by blocking the inappropriate T cell response and blocking the release of inflammatory cytokines such as TNFα , IL-1β , IL-2 and IFNγ .

Avidex has shown that RhuDex®, at the doses studied, and including a 5 day continuous dosing period, is well tolerated. The bioavailability and pharmacokinetics suggest once or twice a day dosing is feasible. Additionally, there were no safety concerns that prevent progression to patient studies.

Avidex will now be starting a pilot phase I/II study in RA patients. The study is designed to investigate safety, pharmacokinetics and drug interactions in patients and is planned to start recruitment from mid 2006. A secondary objective of the study is to measure the effect of RhuDex® on levels of acute phase proteins in patients. Reduction in the levels of such proteins following administration of drugs in clinical trials has been shown to correlate with clinical efficacy in RA. This will be a dose escalating, double blinded study.

Mr James Noble, Chief Executive Officer, said: “We are extremely pleased to be entering the next phase of the development of RhuDex®. We believe RhuDex® has significant potential for the treatment of rheumatoid arthritis as not only does it intervene at the early stage of the disease process but is also orally available. Successful completion of the phase I studies on RhuDex® has already greatly increased the value of this compound to the company going forward.”

About Avidex

Avidex is a biotechnology company focused on the development of small molecule and protein therapeutics involving T cell receptors - either as drug targets or as the therapeutic molecule. Avidex has two key programmes leading to novel treatments in cancer, inflammation and autoimmune diseases. Its breakthrough monoclonal T cell receptor (mTCR) technology enables the production of fully human, soluble T cell receptors. These mTCRs can deliver immunological effector molecules to cancer cells, and can block activation of T cells in autoimmune disease.

In April 2002, Avidex entered into an exclusive licence agreement with the Swedish company Active Biotech AB (Stockholm: ACTI.ST) http://www.activebiotech.com, covering Active Biotech’s patented small molecule CD80 antagonists. The Agreement gave Avidex the exclusive right to evaluate these small molecules, and to develop and market products incorporating them or their derivatives. Since the signing of the Agreement, Avidex has made significant progress. Highly potent orally available lead compounds with activity in biochemical and cellular assays were identified for further optimisation. From this work Avidex selected its lead compound, RhuDex®.

Avidex was formed in 1999 as a spin out from Oxford University. The Company employs 39 staff and is based in Milton Park, near Oxford, UK. The Company has raised over £35 million to date, and investors include Advent Venture Partners, Oxford Technology Venture Capital Trust plc, Quester and Syngenta.

About rheumatoid arthritis (RA)

Rheumatoid arthritis is an autoimmune disease that causes chronic inflammation of the joints. Rheumatoid arthritis can also cause inflammation of the tissue around the joints, as well as other organs in the body. Autoimmune diseases are illnesses which occur when the body tissues are mistakenly attacked by its own immune system, caused by T cell aberrant activation. There is no known cure for rheumatoid arthritis; current treatments focus on reducing joint inflammation and pain.

T cell activation is dependent on two key binding steps - firstly between the T cell receptor and HLA interface, and a ’second signal’ co-receptor binding event involving CD80, which is at high levels in chronically diseased tissues, and CD28 on the T cell. RhuDex® therefore offers a novel approach in the treatment of RA by blocking the CD80-dependent co-stimulatory signal to down-regulate early stages of the inappropriate T cell response in autoimmunity.

Traditional treatments for RA consist of fast acting, oral, first-line drugs, which include non-steroidal anti-inflammatory drugs (NSAIDs) and corticosteroids, and slow acting ’second line’ drugs known as disease modifying antirheumatic drugs (DMARDs). However, over time irreversible joint destruction and disease progression still take place. Long term treatment can also cause unwanted side effects and toxicity. More recently, antibody based products to block inflammatory cytokines such as tumour necrosis factor (TNF), have come onto the market, but these have to be given parenterally.

Contact Information

Dr Neill Moray MacKenzie

Chief Business Officer

Avidex Limited

Contact via E-mail