Plexisyl-AF™

Plexisyl-AF is a medical device under clinical development to prevent the onset of post-operative atrial fibrillation (POAF) in patients undergoing open chest cardiac surgery such as coronary bypass grafting or valve repair.

The product consists of a proprietary PEG (Polyethylene Glycol) biopolymer, an applicator system and a device to assist in identifying the correct injection sites on the surface of the atria of the heart. These sites, termed ganglionated plexi or fat pads, are distinct structures that act as critical relays in the complex cardiac neural network. This network is mediated by the vagus nerve and the sinoatrial node. Research indicates that the likely trigger of persistent and clinically relevant POAF stems from an imbalance in electric conductivity that is caused by the surgical manipulation of the heart. To prevent this disturbance in the heart’s nervous system, Plexisyi-AF is applied to the relevant fat pads thus providing a protective, fully-reversible isolation or parasympathectomy of the vagal input to the heart. Plexisyi-AF biopolymer polymerizes upon injection to neutralize the fat pad conduction pathways but it eventually dissolves and is bioabsorbed within a few weeks, leaving behind no visible effects. However, during the period that Plexisyl-AF is present, it is intended to block the trigger for persistent post-operative atrial fibrillation.

The components of Plexisyl-AF are manufactured for Cardio Polymers according to Good Manufacturing Practices. The biopolymer being employed is approved for clinical use for other indications by the FDA and has been used extensively such that its safety and tolerability are well defined. The mechanism of action relies purely on physical pressure rather than pharmacologic interactions. Thus, Plexisyl-AF is classified as a medical device.

Clinical development for Plexisyl-AF began in 2007 with two multicenter safety (Phase I) studies conducted in four university hospitals in Germany. The studies established the feasibility of the procedure and the safety of the product. As a next step, Cardio Polymers will conduct a Phase II trial with the objective of determining the appropriate dosage of the biopolymer. This clinical study will include comprehensive electrophysiologic testing procedures and is projected to begin in the United States in the fall of 2009.

Plexisyl-AF has not received premarket approval and is not currently marketed in any country. It is currently subject of clinical investigation.