An experimental new immune therapy for rheumatoid arthritis has shown significant promise in two small studies reported by researchers in England.
The results of the studies, sponsored by the maker of the experimental drug, were published Saturday in The Lancet, an international medical journal. About 2-million Americans have rheumatoid arthritis.
One study found impressive responses among 73 people with active rheumatoid arthritis for whom other therapies had failed and who received one intravenous injection of the experimental drug. The second reported the drug could be used successfully against recurrences of the condition.
The drug blocks the action of an important inflammatory protein, called tumor necrosis factor alpha (or TNF-alpha), which is commonly found in rheumatoid arthritis and triggers a chain reaction that damages joints. The frequency of improvement and the speed with which it developed was greater than the responses recorded in similar drug studies, the authors said.
Dr. Ravinder N. Maini of Hammersmith Hospital in London said that his team was confident that its findings "define a major new direction" for arthritis therapy.
The Arthritis Foundation in Atlanta expressed cautious optimism about the new report, saying it "may offer hope for the future." The practicality of the therapy is uncertain because the drug has to be injected by vein and the long-term benefits and risks are not known because the new drug has not been studied long enough, the foundation said. Because of the small number of participants in the two studies, long-term and larger-scale research is needed, the foundation said.
Both studies were paid for by Centocor Inc. of Malvern, Pa., the drug's manufacturer.
The larger study, the one with 73 people, involved people 18 to 75 years old in Austria, England, Germany and the Netherlands who had severe arthritis and had taken an average of three standard anti-arthritis drugs. Neither the doctors nor the patients knew whether the experimental drug or a placebo was being used.
The participants had on average 22 swollen joints before taking the drug. Four weeks later, 19 of the 24 who took a higher dose and 11 of 25 treated with a lower dose of the drug had improved compared with two of 24 in the group that took the placebo. Those in the group that took the higher dose averaged nine swollen joints; those in the group that took the lower dose averaged 13 swollen joints.
Their average score on a pain index dropped to 2.5 from 6.7 on a 10-point scale among those who took the higher dose and to 4.2 from 6.6 for those who took the lower dose.
"The magnitude of these responses was impressive" in relieving tender, swollen joints and improving other arthritis problems, Maini's team reported.
Some patients relapsed after the therapy, suggesting that the drug will have to be given periodically, the authors said.
So the researchers conducted a second study in which those with flare-ups of rheumatoid arthritis received repeated therapy. The drug successfully managed the flare-ups, thus providing an alternative to traditional treatments such as hospital admission and high doses of steroids, the report said.
One patient had pneumonia, which was possibly related to the therapy.