About Etarfolatide (EC20)Etarfolatide is a folate receptor-targeted companion diagnostic imaging agent that is being developed as a non-invasive method to identify tumors that over-express folate receptors. These tumors are the molecular target of Endocyte's folate receptor-targeted therapeutic compounds such as vintafolide. Folic acid is used with etarfolatide for the enhancement of image quality. To date, etarfolatide and folic acid have been administered to over 590 patients. About Vintafolide (MK-8109/EC145) Vintafolide is a proprietary, injectable, conjugate consisting of folate (vitamin B9) linked to a potent vinca alkaloid anti-cancer agent, desacetylvinblastine hydrazide (DAVLBH). Folate is essential for cell division, and cancer cells generally consume higher levels of folate than normal cells to fuel their rapid rate of growth and division. In order to satisfy the demand for folate, some cancer cell types – including ovarian – express high concentrations of folate receptors on their surface. Vintafolide, a novel small molecule drug conjugate (SMDC), is designed to exploit this characteristic by selectively targeting the folate receptor to deliver the anti-cancer agent DAVLBH intracellular to the tumor. Endocyte is developing and commercializing vintafolide with Merck, known as MSD outside the United States and Canada; both studies are also using Endocyte's investigational companion diagnostic imaging agent, etarfolatide. About Endocyte Endocyte is a biopharmaceutical company developing targeted therapies for the treatment of cancer and inflammatory 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.