This article has been updated to correct that Vectra DA doesn't predict which patients will respond to TNF inhibitors but tracks patients' response to the drugs.
By Turna Ray
Crescendo Bioscience this week presented data indicating that its Vectra DA test can track whether Japanese patients with rheumatoid arthritis will respond to anti-TNF therapy.
The researchers, who presented the data at the American College of Rheumatology and Association of Rheumatology Health Professionals’ annual meeting, said that the multi-biomarker-based algorithm has already been validated in Caucasian patients.
Crescendo presented data from a 147-patient study that suggested the multi-biomarker algorithm score underlying Vectra DA could gauge which patients were responding to anti-tumor necrosis factor treatments, such as Abbott's Humira (adalimumab), Amgen/Pfizer's Enbrel (etanercept), and Janssen Biotech's Remicade (infliximab).
Vectra DA's multi-biomarker disease activity score "reflects clinical disease activity and changes in the score are associated with clinical response in Japanese patients initiating anti-TNF therapy," the researchers concluded in an abstract presented at the meeting. These results "are similar to those observed in predominantly Caucasian populations, suggesting that the behavior of the … biomarkers is generally consistent between Japanese and Caucasian ethnic groups."
Researchers estimate that approximately 30 percent of rheumatoid arthritis patients have a "robust" response to TNF inhibitors, while around one-third have no response at all. The rest fall somewhere in the middle.
Most doctors currently assess whether rheumatoid arthritis patients are responding to treatment by determining if their symptoms improve and they are maintaining joint function. These evaluations are based on qualitative assessments and laboratory measures. "The Vectra DA algorithm score provides not only a more objective measure of disease activity, but also identifies patients whose signs and symptoms improve, but continue to have joint damage," a Crescendo spokesperson told PGx Reporter. In this way, "Vectra DA may identify patients who otherwise may not receive appropriate management."
Crescendo launched Vectra DA last year as a lab-developed test that assigns a score between one and 100 to quantify rheumatoid arthritis disease activity (PGx Reporter 11/17/2010). The company is in the process of developing a predictive diagnostic test to gauge patients' response to rheumatoid arthritis drugs, called Vectra TS.
The latest Vectra DA study was led by Shintaro Hirata of the University of Occupational & Environmental Health in Japan, the same institution where rheumatoid arthritis patients for the study were enrolled and given one of three anti-TNF treatments.
The study investigators, including researchers from Crescendo, measured 12 biomarkers using custom immunoassays on Meso Scale Discovery's multi-array platform. Although the biomarker panel for Vectra DA normally includes C-reactive protein, for this study Hirata et al. looked at whether the biomarker panel excluding CRP measures could still gauge disease activity.
Using the 12-biomarker-based Vectra DA clinical score, the study investigators placed patients into low and moderate/high disease activity categories. The researchers then correlated these biomarker-based scores with measures from a disease activity score calculator, DAS28, which includes CRP.
The study showed that the Vectra DA score "is strongly associated with clinical disease activity in Japanese patients," the Crescendo spokesperson said, adding that "the biomarkers other than CRP provide information about disease activity over and above that provided by CRP alone."
The study findings support the indication of Vectra DA as a tool intended to be used in conjunction with clinical assessment of rheumatoid arthritis, not as a replacement for clinical assessment, the spokesperson noted.
Additionally, by monitoring the change in patients' Vectra DA biomarker score over a year, the researchers were able to assess which patients were responding to anti-TNF therapies and which patients were not responding. When patients were first enrolled in the study, they had median age of 60, median DAS28 of 5.7, and disease duration of 60 months. At one year, "fifty-six percent of patients had good … responses," the authors reported in the abstract.
"These results show that the Vectra DA algorithm score provides added value about disease activity above that provided by CRP and confirm the association with disease activity seen in other studies," Crescendo said in a statement.
According to the Centers for Disease Control and Prevention, more than 2 million adults in the US have RA. The disease can lead to long-term joint damage that can be debilitating. According to the Arthritis Foundation, people with rheumatoid arthritis are two times more likely to die as are persons of the same age without the disease.
Crescendo is currently involved in a large trial in which researchers are trying to validate a gene expression signature and discover new biomarkers associated with response to anti-TNF treatments. The study, called Biomarkers of Anti-TNF Treatment Efficacy in Rheumatoid Arthritis to Define Unresponse Populations, or BATTER-UP, is enrolling 1,000 patients who are being treated by one of several marketed anti-TNF drugs. In addition to Crescendo's involvement, the study is being funded by Biogen Idec, Bristol-Myers Squibb, Centocor Research & Development, Genentech, Medco Health Solutions, Regeneron Pharmaceuticals, and Sanofi-Aventis (PGx Reporter 11/17/2010).
In September, Myriad made a $25 million strategic debt investment in Crescendo. Under this deal, Myriad has a three-year, exclusive option to acquire the South San Francisco, Calif.-based company if it meets minimum revenue milestones (PGx Reporter 9/14/2011).
In a recent presentation, Myriad Genetics CEO Peter Meldrum suggested the company is keeping an eye on the development and market growth of the Vectra DA test as it is the lead product in Crescendo's pipeline.
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