Seragen Inc.'s interleukin-2 receptor targeted fusion toxinDAB486IL-2 is able to produce a statistically significantimprovement in the clinical symptoms of some rheumatoidarthritis patients, according to the latest results of thecompany's double-blind Phase II clinical trial.
Larry Moreland, director of clinical intervention programs atthe University of Alabama, Birmingham, presented the trialresults on Sunday at the jointly sponsored Annual Meeting ofthe Association of American Physicians, the American Societyof Clinical Investigation and the American Federation forClinical Research in Washington, D.C.
According to Moreland, of the 45 patients enrolled in the firstcourse of the study, 23 received placebo and 22 receivedDAB486IL-2.
Four of those 22 had a response to the experimental drug afterone course of treatment, which consisted of 0.7 milligrams perkilogram per day for five consecutive days, explained HelenMaslocka, director of corporate communications for theHopkinton, Mass., company (NASDAQ:SRGN). In this case, aresponse was defined as 25 percent or greater reduction inboth the number of swollen joints and the number of tenderjoints, together with 25 percent or greater improvement in atleast two of six standard rheumatological criteria.
Because none of the patients receiving placebo responded, thenumber of patients in the treatment group who responded isstatistically significant, according to the company.
"Patients in rheumatoid arthritis studies often demonstrate amodest improvement with placebo treatment," said JeanNichols, senior vice president at Seragen. "The lack of placeboeffect in this study indicates that the response criteria wererigorous enough to demonstrate improvement associated withDAB486IL-2."
Subsequently, 34 patients altogether received three courses ofthe fusion toxin at monthly intervals. Eleven of those patientsresponded to the therapy with at least 60 percent reduction inthe number of swollen and/or painful joints as well as 60percent or greater improvement in grip strength and morningstiffness. An additional seven patients showed measurableimprovement.
Seragen has a newer, improved version of its IL-2 fusion toxin,known as DAB389IL-2, in Phase I/II clinical trials forrheumatoid arthritis, as well. DAB389IL-2 is a smallermolecular weight compound than its predecessor, is able tobind the IL-2 receptor approximately five times better, is 10times more potent, and three times less toxic than 486,according to the company.
The results on the Phase I/II DAB389IL-2 trials should be inby the end of this summer, when Seragen will decide which ofthe two DAB versions it will take into advanced clinicaldevelopment, Maslocka told BioWorld.
-- Jennifer Van Brunt Senior Editor
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