In vitro and in vivo data presented showed that etarfolatide binds with high affinity (Kd around 3 nM) to the folate receptor, independent of cell type. Furthermore, the binding specificity of etarfolatide to cells or its accumulation within tumors depends on folate receptor expression. The pharmacologic properties of both etarfolatide and vintafolide were investigated in human and murine cell lines as well as in xenograft (transplants into other species) models.
"These data indicate that we can predict with our companion diagnostic etarfolatide which tissues will accumulate, and potentially respond to, folate-containing therapeutics like the SMDC vintafolide, which is a much needed personalized approach," said Christopher Leamon, Ph.D., vice president of research and development for Endocyte and presenter of the study.
Endocyte has a pipeline of folate receptor-targeted SMDCs in various stages of clinical and preclinical development for the treatment of folate receptor-positive cancers and inflammatory diseases.
About Ovarian CancerIt was estimated that in 2012, there were 22,280 new cases of ovarian cancer in the United States and over 40,000 new cases in the European Union. Ovarian cancer causes more deaths than any other cancer of the female reproductive system. Overall, approximately 80 percent of patients relapse after first-line platinum-based chemotherapy. Ovarian cancer is a challenging disease with a high unmet need: it typically recurs within six months of completion with a platinum-containing regimen, the standard of care for ovarian cancer. An estimated 80 percent of ovarian cancer patients have been found to have folate receptor-positive disease, and 40 percent express the receptor in all of their target tumor lesions. Compared to patients who do not express folate receptors on their tumors, folate receptor-positive patients have been shown to have a poorer overall prognosis. About Lung Cancer Lung cancer is the leading cause of cancer deaths in the industrialized world. More than 200,000 new cases of lung cancer are diagnosed each year in the United States, and more than 160,000 deaths occur annually from the disease, according to the American Cancer Society. The disease is frequently undiagnosed until it has already developed to advanced stages, resulting in a five-year survival rate of only approximately 15 percent. Approximately 85 percent of patients diagnosed with lung cancer are identified with non-small cell lung cancer, and of these patients 40 to 50 percent have adenocarcinoma and 30 to 35 percent have squamous cell carcinoma.