Clinical Study Shows Involvement of Activated Macrophages in Osteoarthritis, Identified by Endocyte's Etarfolatide

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.

The study investigated 25 patients with symptomatic radiographic OA of at least one knee. Using the Kellgren-Lawrence grading, a grading scale to determine the presence and severity of OA, all knees showed evidence of radiographic OA. The study was supported by Endocyte and Eli Lilly.

Etarfolatide is a folate receptor-targeted companion diagnostic imaging agent being developed as a non-invasive method to identify cells that over-express folate receptors, which allows imaging of activated macrophages that are associated with inflammatory diseases. Approximately 27 million people are affected by OA in the United States and more than 250 million people worldwide are affected by knee OA. Most of these patients rely on drugs to treat symptoms, but there are no drugs approved to treat the underlying cause of the disorder.

About Endocyte

Endocyte is a biopharmaceutical company developing targeted therapies for the treatment of cancer and other serious diseases. Endocyte uses its proprietary technology to create novel SMDCs and companion imaging diagnostics for personalized targeted therapies. The company's SMDCs actively target receptors that are over-expressed on diseased cells, relative to healthy cells. This targeted approach is designed to enable the treatment of patients with highly active drugs at greater doses, delivered more frequently and over longer periods of time than would be possible with the untargeted drug alone. The companion imaging diagnostics are designed to identify patients whose disease over-expresses the target of the therapy and who are therefore more likely to benefit from treatment.

For additional information, please visit Endocyte's website at


CONTACT: Mitel Europe Mitel, Marieke Adama Tel: +31 (0)30 8500 030 e-mail: Yvon Reitsma Tel: +31 (0)317 410 483 e-mail: Mitel North America Stephanie Ascher, Stern Investor Relations, Inc. (212) 362-1200 Martina Schwarzkopf, Ph.D., Russo Partners (212) 845-4292 Tony Russo, Ph.D., Russo Partners (212) 845-4251 tony.russo@russopartnersllc.comSource:Endocyte, Inc.