Abatacept Linked to Sustained Response in Treatment-Resistant Rheumatoid Arthritis: Presented at ACR

[Guest guest]

Abatacept Linked to Sustained Response in Treatment-Resistant Rheumatoid Arthritis: Presented at ACR

http://www.docguide.com/news/content.nsf/news/8525697700573E18852570BB005F053ASAN DIEGO, CA -- November 16, 2005 -- Treatment with the investigational biologic agent abatacept (Orencia) appears to be associated with a sustained response through 18 months of follow-up in patients for whom anti-tumor necrosis factor (TNF) agents have been ineffective.Principal investigator Mark Genovese, MD, Associate Professor of Medicine, and Associate Chief, Division of Immunology and Rheumatology, Stanford University School of Medicine, Stanford, California, United States, presented the findings here November 15th at the annual scientific meeting of the American College of Rheumatology (ACR)."The findings looked similar to what we had seen in the first 6 months," Dr. Genovese said, referring to the double-blind phase of the Abatacept Trial in Treatment of Anti-TNF INadequate responders (ATTAIN) trial.The findings he presented were from an open-label extension phase that lasted an additional 12 months."Patients who continued on treatment continued to benefit, and patients who were switched benefited in a similar manner," he said. "Long-term use in this population continued to look good and reasonably safe."Because of the encouraging results in the double-blind phase of ATTAIN, the investigators wanted to see if the efficacy and safety of abatacept would be maintained through a total of 18 months of treatment.At the end of the double-blind and the open-label phases, the investigators assessed patients' responses as defined by reductions of symptoms by 20%, 50%, and 70% according to the ACR criteria (ACR20, ACR50, and ACR70), as well as their responses to the Health Assessment Questionnaire (HAQ) and the Disease Activity Score 28 (DAS28).At baseline, all 258 patients had had an inadequate response to at least 3 months of treatment with at least one anti-TNF agent due to lack of efficacy.During the double-blind phase, the investigators randomized patients to either a fixed dose of abatacept, consisting of approximately 10 mg/kg, or to placebo. Patients received an intravenous infusion of either the study drug or placebo on days 1, 15 and 29 of the study and every 28 days thereafter.In the extension phase, which was open to all patients who completed the double-blind phase, all patients received a once-monthly fixed dose of abatacept at approximately 10 mg/kg, along with at least one background disease-modifying anti-rheumatic drug (DMARD).After a washout period, the study design excluded the use of anti-TNF therapies.Among the patients in the double-blind phase, 223 (86.4%) completed treatment and 218 (84.5%) entered the extension phase. Among those who entered the extension, 168 patients completed 18 months of treatment.On the last day of the double-blind phase, 59.4% of patients who entered the long-term phase on active treatment had an ACR20 response; 23.5% had an ACR50 and 11.5% had ACR70 responses. In addition, 11.2% of patients had achieved remission according to DAS28 criteria.On the last day of the extension, 56.7% of patients had an ACR20; 35.0% had an ACR50, and 18.0% had an ACR70. The remission rate was 22.5%.The adverse events in the extension phase were similar to those seen in the double-blind phase, Dr. Genovese said. These were typically headaches and peri-infusional events, with a rate of 79.5% in the treatment group and 71.4% in the placebo group for all adverse events.The researchers also found that 2.3% of patients in each treatment group had serious adverse events in the extension phase, consisting of infections and malignancies.The study was funded by Bristol Myers Squibb, which manufactures Orencia.[Presentation title: Sustained Improvements Through 18 Months With Abatacept In Rheumatoid Arthritis Patients With An Inadequate Response To Anti-TNF Therapy. Abstract L16]