Medical Device Daily National Editor

This drug/device thing seems to be catching on, and catching on a lot in cardiology. Drugs can be put on stents, so why not put them on and around other types of implanted devices?

So says TyRx (Monmouth Junction, New Jersey), a company focused on drug/device combinations for this – and getting additional traction with new rules from the Centers for Medicaid & Medicare Services.

TyRx is combining its polymer technology with drugs, placing these on a fabric "envelope" into which you put your implanted electronic rhythm device, the envelope then helping to keep the implanted device in firm position and also eluting the anti-bacterial drugs to reduce the chance of infection at the implant site.

The company has just rolled out its latest drug/device combination product, named AIGISRX ICD, a mesh envelope implanted in conjunction with an ICD and having the dual function of firmer device placement and anti-infective action.

So TyRx is hoping that hospitals – and patients – will be saying, "The envelope, please!" preliminary to implanting these devices.

Bill Edelman, CEO of TyRx since 2004 – the company itself formed in 1998 – separates the company's strategy from drug-eluting stent (DES) technology for preventing reclogged arteries, telling Medical Device Daily that "the coating and the drug we use are intended to destroy any possibility of post-implant infection." But he adds: "All these ideas come from similar underlying hypothesis: Putting a substrate, a therapeutic agent, on a device alters some of the characteristics of the device, once deployed."

Its technology is based on a class of tyrosine-based biodegradable polymers, called polyarlylates. Using combinatorial chemistry, TyRx says it has created libraries of related polymers with "varied chemical structures and predictable physical properties." It then used a proprietary polymerization process to synthesize more than 100 tyrosine-based polymers to create custom polymers meeting precise specifications.

During a procedure to implant a CRMD, the physician inserts the pacemaker or ICD into the AIGISRX anti-bacterial envelope and positions the device normally within the surgically created pocket – the anti-bacterial quality connecting to the term AIGIS, a permutation of the Latin aegis, the shield of Zeus, Edelman said.

The company currently is working in a healthcare sweet spot, given the national U.S. focus on attempting to prevent those dreaded nosocomial (hospital-acquired) infections that are giving hospitals a bad name among patients and — even more significantly, given hospital economics — the CMS. CMS says it is determined to withhold payment for treatment of infections it considers unnecessary and preventable.

TyRx cites a Federal Registry notice in which CMS states that surgical site infections "following certain cardiac device procedures is a strong HAC (hospital-acquired condition) candidate. The condition is high cost and high volume, triggers a higher-paying MS-DRG, and may be considered reasonably preventable through the application of evidence-based guidelines ... [W]e expect to propose surgical site infection following certain cardiac device procedures ... as future candidate HACs."

Edelman acknowledges that CMS is not yet withholding payment for infections at surgical sites related to ICD or pacemaker implants, but said it is inevitable that the company's products will cover a variety of the infections targeted by CMS for non-reimbursement.

"We're absolutely aiming our investment thesis at the questions that CMS has raised," he said.

And AIGISRX, the company said in a statement, "offers a solution which may meet the thresholds of high cost, high volume and reasonably preventable hospital-acquired conditions through the application of evidence-based guidelines selection criteria set by CMS."

The company says that in in vitro studies, AIGISRX CRMD demonstrated antimicrobial activity against Methicillin Resistant Staphylococcus aureus (MRSA), Staphylococcus aureus, Staphylococcus epidermidis, Acinetobacter baumanii, Enterobacter aerogenes and Proteus mirabilis, which represent a majority of the infections reported in CRMD-related endocarditis, including "superbugs." One of its initial products is a hernia repair mesh, named Pivit.

Launch of AIGISRX ICD extends to the ICD sector the company's platform technology, branded as AIGISRX CRMD (cardiac rhythm management device), previously represented by its AIGISRX PM product, for implantation with a pacemaker implant.

TyRx received FDA clearance of AIGISRX CRMD in January (Medical Device Daily, Jan. 29, 2008). AIGISRX provides an adjunct to general antibiotic therapy by eluting the antimicrobial agents rifampin and minocycline. The company says that since May the AIGISRX PM has been implanted in more than 600 patients nationwide.

Ali Massumi, MD, director of the Center for Cardiac Arrhythmias and Electrophysiology at St. Luke's Hospital (Rapid City, Iowa) and clinical professor of medicine at Baylor College of Medicine (Houston) performed the first-in-man procedure using AIGISRX PM this past May. Besides noting the device's ability to stabilize the device in the body, Massumi said it also makes it easier "for future device replacement."

Edelman said the company's strategy is to both broaden and deepen its product offerings.

In cardiology, it will seek applications for placing coating electrophysiology device leads with its polymer/disinfectant combinations to fight contamination. Another goal is in orthopedics, to prevent bone infections associated with sternotomy procedures.

In 2009, the company will be in clinical trials for cosmetic reconstructive procedures, "to inhibit a common scar formation around a breast implant," Edelman said.

TyRx in February raised $25 million in a venture capital financing led by Clarus Ventures (Cambridge, Massachusetts) and Pappas Ventures (Durham, North Carolina) (MDD, Feb. 29, 2008). Edelman said this investment will carry it through to break-even point and that it is not now looking for new investment.

"Given our product design and the way we've configured our business" – with a focus on the 510(k) path, he said – "we've been able to leverage our balance sheet very effectively to advance the company."

TyRx is developing its technologies, in part, via patents licensed from Rutgers University (Piscataway, New Jersey). Additionally, it has exclusive licenses from Baylor College of Medicine and The University of Texas M.D. Anderson Cancer Center (Houston).

In 2005 it reported receiving an equity investment from Boston Scientific (Natick, Massachusetts) for DES work (MDD, Feb. 1, 2005), but Edelman said that Boston Scientific is no longer a partner. He said TyRx has a new partner, which he declined to disclose at this time.

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