Crescendo Bioscience, a wholly-owned subsidiary of Myriad Genetics, Inc., has presented new data that showed Vectra® DA is a better predictor of radiographic progression over two years than other tests used to assess risk of joint damage in rheumatoid arthritis (RA), such as C-reactive protein (CRP). The oral presentation was featured at the 2014 American College of Rheumatology (ACR) Annual Meeting in Boston, Massachusetts.
The study included 143 patients with RA who had received a stable treatment and were enrolled in the Brigham and Women's Rheumatoid Arthritis Sequential Study (BRASS) registry in the United States. Patients were evaluated at their initial visit in the BRASS registry for the Vectra DA score and conventional measures of disease activity, including CRP, DAS28-CRP, CDAI, SDAI and RAPID3, and provided X-rays of hands and wrists at approximately the initial visit and two years later. These data were used to assess the relationship between disease activity and the amount of subsequent new joint damage seen on X-rays (radiographic progression).
The results showed that Vectra DA was the best independent predictor of disease progression over two years when compared with standard measures based on the exam or patient reported outcome. The odds ratio for predicting progression was highest for Vectra DA and lowest for RAPID3. Importantly, among patients with a low CRP at baseline, defined as <1 mg/dL, radiographic progression was observed in 34.8 percent of patients with a high Vectra DA score versus 8.1 percent of patients with a low/moderate Vectra DA score (p=0.003), providing further evidence that Vectra DA provides information for predicting joint damage that is not provided by CRP.
"In this study of U.S. patients, Vectra DA was a strong predictor of joint damage over two years, compared with other tests," said Eric Sasso, M.D. Vice President, Medical and Scientific Affairs at Crescendo Bioscience. "These data build on prior studies demonstrating that Vectra DA can assess risk for joint damage and complement other measures of disease activity."
Another study featured at ACR provided an analysis of radiographic progression in patients with early RA from the Swedish Farmacotherapy (SWEFOT) clinical trial. The Vectra DA test was used to evaluate 220 patients for progression from baseline to Year 1 and from baseline to Year 2. In addition, progression from Year 1 to Year 2 was evaluated for 133 patients who had inadequate initial responses to methotrexate and were treated from month three with the addition of a TNF inhibitor or with triple therapy using methotrexate, sulfasalazine and hydroxychloroquine.
Among patients with a high Vectra DA score at baseline, 25 percent of those with a high Vectra DA score at month three showed rapid radiographic progression during the first year, and 35 percent of those with high Vectra DA score at one year showed rapid radiographic progression between Year 1 and Year 2. By contrast, for patients whose high baseline Vectra DA score declined to low after three months or one year of treatment, only 6 and 4 percent showed rapid radiographic progression between Year 1 and Year 2. Moreover, for patients who had a moderate Vectra DA score at baseline and achieved a low Vectra DA score at 3 months, none showed rapid radiographic progression during the first year.
"In this study, a high Vectra DA score was associated with markedly increased risk for joint damage and a low Vectra DA score was associated with low risk for subsequent joint damage," said Dr. Sasso. "These findings suggest how Vectra DA may be used to objectively assess disease activity following initiation of therapy to help manage the patient's disease."