FDA Clears Cardiac Rhythm Medical Device Anti-Bacterial Envelope


March 3, 2008

March 3, 2008 – The FDA granted 510(k) clearance for the AIGISRX CRMD Anti-Bacterial Envelope by Tyrxpharma, a cardiac rhythm medical device intended to immobilize and reduce bacterial infection of a pacemaker or implantable cardioverter defibrillator (ICD) in order to create a stable environment when implanted in the body.

AIGISRX CRMD contains the antimicrobial agents, rifampin and minocycline, which have been shown to reduce infection by organisms representing a majority of the infections reported in CRMD related endocarditis, including Methicillin Resistant Staphylococcus Aureus (MRSA). This device is only intended to be used in conjunction with pacemakers and implantable cardioverter defibrillators

The envelope is constructed of knitted filaments of polypropylene coated with a proprietary resorbable polymer that elutes the antimicrobial agents rifampin and minocycline for a minimum of 7 days to reduce the risk of infection of the implanted CRMD following surgery.

According to the manufacturer, AIGISRX CRMD also demonstrated in vivo effectiveness in reducing infection compared to control in a series of animal studies in which CRMDs were placed into AIGISRX CRMD envelopes and implanted into subcutaneous pockets inoculated with various bacterial strains, representing a majority of the infections associated with CRMD related endocarditis. Both AIGISRX CRMD and the controls (CRMD without envelope) were inoculated and observed for a minimum of 7 days to validate the presence of infection in the animals. The bacteria tested included Staphylococcus epidermidis, Acinetobacter baumanii, Staphylococcus capitis and

Escherichia coli, and separately, Staphylococcus aureus which represent a majority of the infections reported in CRMD-related endocarditis. It should be noted that the in vitro and in vivo activity of the AIGISRX CRMD antimicrobials is variable against non-epidermidis strains of coagulase-negative staphylococci.

According to a recent study presented during the Heart Rhythm Society 2006 Scientific Sessions, the University of Pittsburgh Medical Center noted that the 2003 national incident of infection for pacemakers was estimated to be 5.82 percent and for ICDs 3.71 percent.

Recent market research indicates that more than 400,000 CRMDs are implanted each year in the U.S.

“We are thrilled to have reached this value-creating milestone with the FDA clearance of AIGISRX CRMD,” said Bill Edelman, CEO of TyRx Pharma. “With over 400,000 annual U.S. implants of CRMDs, we believe AIGISRX CRMD will become a valuable tool in the effort to suppress bacterial infection of CRMD pockets.” Mr. Edelman continued, “We anticipate AIGISRX CRMD U.S. national commercial distribution to begin within the quarter following this FDA clearance, with full market release coinciding with the Heart Rhythm Society Heart Rhythm 2008, the premier conference on cardiac arrhythmias in San Francisco May 14-17, 2008,” Rabih O. Darouiche, M.D., director of the Center for Prostheses Infection at Baylor College of Medicine, Houston, Texas commented, “This first-in-class anti-infective approach is likely to yield tremendous benefit to both patients and clinicians taking into consideration the growing risk of infection and the severe consequences for those patients who may develop an infection.”

For more information, please visit www.tyrxpharma.com