AACHEN & FRANKFURT, Germany--(BUSINESS WIRE)--The biopharmaceutical company PAION AG (ISIN DE000A0B65S3; Frankfurt Stock Exchange, Prime Standard: PA8; London AIM: PAI) and ERGOMED Clinical Research Limited today announce the completion of an open-label, single-centre Phase IIa study with PAION’s intravenous NMDA receptor antagonist CNS 5161. The study has been completed by PAION and ERGOMED under a Revenue Sharing and Co-Development Agreement signed in July 2006.