Nov. 8, 2010 (Atlanta) -- An experimental pill may help to reduce pain and swelling and improve physical function in people with rheumatoid arthritis, according to findings from a late-stage study of more than 600 patients.
There was also a signal that people given the new drug, tasocitinib, may be more likely to go into remission than people given placebo. However, that finding could have been due to chance, says study leader Roy Fleischmann, MD, of the University of Texas Southwestern Medical Center in Dallas.
The findings were presented at a news briefing here, held in advance of the Fleischmann's formal presentation at the American College of Rheumatology meeting.
The hope is that the new pill will offer patients an attractive alternative to the injectable agents that dominate the RA market, says Alan K. Matsumoto, MD, of Arthritis and Rheumatism Associates in Washington, D.C. He was not involved with the work.
The injectables -- which include Enbrel, Humira, and Remicade -- can cost as much as $1,500 a month and carry a risk of infection, he says.
"The fact that tasocitinib is given orally is extremely exciting," Matsumoto tells WebMD. "If approved, it will become the first new oral drug for rheumatoid arthritis since Arava was OK'd in the late 1990s," he says.
Tasocitinib belongs to a new class of oral drugs, known as JAK inhibitors, that inhibit immune system cells that are thought to cause inflammation.
In rheumatoid arthritis, the immune system is inappropriately turned on, causing inflammation, predominantly in the joints. This, in turn, can cause pain and lead to permanent joint damage.
Tasocitinib Appears to Improve Rheumatoid Arthritis Symptoms
In the study, 611 people with moderate to severe rheumatoid arthritis who had an inadequate response to at least one other drug were randomly assigned to one of two doses of tasocitinib or placebo.
Among the findings:
A total of 66% of patients who received the higher dose of tasocitinib had at least a 20% improvement in disease activity and symptoms after three months of treatment, compared with 60% of those given the lower dose and 27% of those who received a placebo.
Scores on a questionnaire that asks about dressing, arising, eating, walking, hygiene, reach, grip, and activities improved more than twice as much in people taking either dose of tasocitinib, compared with placebo.
But for the third primary study goal, remission according to the Disease Activity Score-28 (DAS-28) at three months, tasocitinib did not offer a substantial advantage at either dosage relative to placebo.
DAS-28 scores take into account such measures as the number of joints tender to the touch and the number of swollen joints. Using this measure, 10% of patients on the higher tasocitinib dosage, 6% on the lower dose, and 4% on placebo were in remission at three months. But the difference in remission rates did not reach what doctors call statistical significance, Fleischmann tells WebMD. He says he received consulting fees and research support from Pfizer, which makes the drug and funded the new study.