New Data for Vectra DA Test in Rheumatoid Arthritis Presented at ACR

Results released today in Boston at the 2014 meeting of the American College of Rheumatology (ACR) show that the Vectra DA test better predicts radiographic progression of rheumatoid arthritis (RA) over 2 years than other tests used to gauge how much joint damage patients will experience, according to Myriad Genetics, which earlier this year purchased Crescendo Bioscience, the test’s maker.

The results demonstrate the growing importance of biomarkers in managed care, not only in areas such as cancer, but also to guide treatment of less-threatening chronic conditions. Test outcomes can make a significant difference to payers if they end up steering physicians toward a more precise, appropriate course of treatment.

Today’s results are from a study of 143 RA patients enrolled in the Brigham and Women’s Rheumatoid Arthritis Sequential Study (BRASS) registry, and were shared in an oral presentation in Boston. In an earlier interview with The American Journal of Managed Care, Eric Sasso, MD, vice president of Medical and Scientific Affairs at Crescendo Bioscience, noted these results are from US patients and said the study group better reflects the US population as a whole; a previous study of the Vectra DA test involved patients from Sweden.

“Even though good science is good science, populations can be different,” Dr Sasso said. “American physicians might be a bit more accepting of data from within the United States.”

According to today’s statement from Crescendo, patients were evaluated for the Vectra DA score and traditional measures of disease activity, including the blood marker C-reaction protein (CRP), and provided X-rays of hands and wrists at the start of the study and 2 years later. “Before” and “after” X-rays are used to gauge how much joint damage the disease causes over time, which is known as radiographic progression.

Study results show that the Vectra DA test, which measures 12 biomarkers, was the best independent predictor of radiographic progression after 2 years, compared with traditional measures, based on the exam and patient-reported outcomes. Data reported at ACR listed the odds ratio of predicting progression highest for Vectra DA and lowest for the RAPID3 test. Among patients with a low CRP at baseline, defined as <1 mg/dL, radiographic progression was observed in 34.8% of patients with a high Vectra DA score compared with 8.1% of patients with a low-to-moderate Vectra DA score (P =.003), which the researchers said provides evidence that the test gives information for predicting joint damage that is not provided by CRP.

Dr Sasso said the Vectra DA test is a more objective test than previous assessments for RA. CRA is a single blood biomarker, while the other measures were “composites” of other measures that he said were “largely subjective in nature”. He said the results presented in Boston reinforce how the Vectra DA score gives rheumatologists better information with which they can make treatment decisions, such as which patients can be expected to progress quickly to the newer biologic therapies for RA.

Another key difference in this study, he said, is that the patients in the Swedish trial were newly diagnosed with RA, while the patients in the BRASS registry had been treated for RA for many years. That could make the results especially important to Medicare, which does fund this test. The typical protocol for Vectra DA testing is twice a year, according to Myriad officials.

Dr Sasso was asked if the Vectra DA test could show RA patients who smoked what continuing the habit would do to their disease progression. Earlier this year, a new report from the US Surgeon General not only linked a higher association of smoking with RA, but also listed smoking as a cause of the autoimmune disease.

“In a statistical sense, the answer is yes,” Dr Sasso said. What Vectra DA could do, he said, is give doctors 1 more tool to show an RA patient who still smokes the 2 courses the disease can take, given the patient’s decision to quit or not.