Etarfolatide Differentiates Inflammatory from Non-Inflammatory Disease States in Osteoarthritis Patients Data Presented at the OARSI 2013 World Congress on Osteoarthritis PHILADELPHIA, April 25, 2013 (GLOBE NEWSWIRE) -- Endocyte, Inc. (Nasdaq:ECYT), a biopharmaceutical company developing targeted small molecule drug conjugates (SMDCs) and companion imaging diagnostics for personalized therapy in cancer and other serious diseases, today announced that the investigational molecular imaging agent etarfolatide (EC20) may identify and differentiate inflammatory from non-inflammatory disease states of osteoarthritis (OA). The results of this study, conducted under the leadership of Virginia Byers Kraus, M.D., Ph.D., professor of medicine at Duke University, were presented at the OARSI 2013 World Congress on Osteoarthritis in Philadelphia. "Imaging of OA patients with etarfolatide enables non-invasive, full-body identification of joints that are currently experiencing active inflammation and therefore suffering from its damaging consequences," said Philip Low, Ph.D., Endocyte's chief science officer and co-author of the abstract. "Activated macrophages overexpress folate receptor ß and thereby can be imaged by the folate-targeted etarfolatide. The data from this study demonstrate that macrophages are involved in OA, and that drugs targeting activated macrophages and their inflammatory pathways may be used to decrease OA symptoms and reduce joint deterioration." The study evaluated the association of etarfolatide uptake with radiographic and clinical measures of OA severity, including joint space narrowing, osteophyte formation and severity of joint symptoms such as pain, aching and stiffness. Activated macrophages, imaged with etarfolatide, were detected in 76 percent of osteoarthritic knees. Intensity of uptake from the etarfolatide images strongly correlated with joint space narrowing (p=0.006), osteophyte severity (p=0.011) and pain and stiffness (p<0.0001). This strong correlation between etarfolatide uptake and joint deterioration as well as OA symptoms provides evidence that involvement of activated macrophages in joint degeneration is likely a factor in OA pathogenesis. Importantly, activated macrophages, identified with etarfolatide scans, were also detected in other joints commonly affected by OA, including hand, shoulder, ankle and foot joints (positive in 30 percent, 26 percent, 12 percent and 16 percent of scans, respectively). Furthermore, etarfolatide uptake in the hand, ankle and foot joints was strongly associated with pain at these sites.