New anti-rheumatoid drugs bring hope
The lives of a number of rheumatoid arthritis sufferers could be eased by a new class of drugs set to become available in the UK by early 2000.
The drugs, infliximab (Remicade™) and etanercept (Enbrel™), have been proven to reduce the symptoms of rheumatoid arthritis – an inflammatory crippling joint condition - in a number of large scale clinical trials carried out over several years in the UK, Europe and the US.
Latest trial results from the US reveal that Remicade also arrests joint damage in patients with long-standing rheumatoid arthritis - the first of the new anti-rheumatic therapies to do this.
"The ability to arrest progression of rheumatoid arthritis has eluded rheumatologists until now," said Professor Maini, whose team has led research in this field. "The rapid and marked improvement of patients' symptoms, and Remicade's apparent ability to halt the progression of rheumatoid arthritis, represents a significant potential breakthrough in treatment. This will be welcome news to rheumatologists and their patients."
One of the scientists behind the development of the new anti-TNF therapy, Professor Tiny Maini, director of the Kennedy Institute in west London, believes it could be as significant in the treatment of rheumatoid arthritis as steroids, which were discovered in the 1950s – but without the thinning of bones and high blood pressure that steroids cause.
Rheumatoid arthritis, which affects around 600,000 people in the UK, is an auto-immune disease in which the body's own immune system attacks the joints, causing inflammation, stiffness and intense fatigue.
Remicade and Enbrel are expected to have a substantial impact on people for whom existing drug therapies do not work – even patients in advanced stages of the disease.
"We're very excited about the development of anti-TNF therapy. Although it's not a cure, it's a huge advance in the treatment of rheumatoid arthritis and could offer relief for many thousands of people," said Professor Maini.
Trials indicate that 70 per cent of the 800 patients who took Remicade in combination with methotrexate reported a drastic improvement in their condition. They felt better in themselves, and much of the swelling and tenderness in the joints went completely. The number of affected joints in the body also reduced.
Remicade is aimed at people who fail to respond to methotrexate alone. Enbrel is expected to be suitable for around 3, 000 RA sufferers with long-established disease, for whom one of more DMARDs (disease-modifying anti-rheumatic drugs) such as cyclophosphamide and sulphasalazine) do not work.
Remicade, which is given to patients through an intravenous drip once a month, works by blocking the process of a disease-causing molecule called TNF (tumour necrosis factor). Enbrel, which is self-injected twice a week and works in a similar way, was approved in the US for use in RA patients in November 1998.
Both anti-TNFdrugs are currently awaiting approval by the European Medical Control Agency, and are expected to gain licences in the UK by early spring 2000. Remicade is already available for use in the chronic bowel condition Crohn's Disease.
Background
The development of Remicade and Enbrel is largely due to pioneering research work started more than ten years ago by scientists working at the Kennedy Institute, the flagship of medical research charity the Arthritis Research Campaign.
They discovered that a man-made monoclonal antibody called cA2 could be used to block the activity of a disease-causing molecule called TNF (tumour necrosis factor) which causes inflammation of the joints in rheumatoid arthritis.
Remicade was developed by the American pharmaceutical company Centocor which went on to fund three phases of multi-centre trials, co-ordinated in Britain and later internationally by Professor Maini. Pharmaceutical company Immunex has produced Enbrel.
Scientists at the Kennedy are continuing to work on anti-TNF studies, funded by the ARC and Centocor, to try to understand the limitation of the new drugs, and to help to produce even more advanced therapies.
