Medical Device Daily Associate

In the wake of recent extensive recalls involving its implantable cardioverter defibrillator (ICD) devices, Guidant (Indianapolis) last week received some welcome news on two of its trials, one for surgical ablation of cardiac tissue and the other for its emerging drug-eluting stent program.

In the first piece of news, the company reported the enrollment of the first patient in a clinical trial designed to study a new therapy for the treatment of permanent atrial fibrillation (AF).

The trial will evaluate the safety and efficacy of the Flex microwave surgical ablation system to treat permanent AF patients undergoing mitral valve surgery. Results of the trial may be used to obtain FDA approval to treat permanent AF with the technology, the company said.

The first patient was enrolled in the trial on June 27 by John Johnkoski, MD, cardiothoracic surgeon, at Wausau Hospital (Wausau, Wisconsin).

Called RESOLVE-AF (RandomizEd Study Of SurgicaL Ablation with MicrowaVe Energy for the Treatment of Atrial Fibrillation), this prospective, randomized trial will enroll 200 patients at up to 40 U.S. and European centers.

Guidant’s Flex system, which includes a surgical ablation probe and microwave generator, directs microwave energy to targeted tissue to induce cell death. The system typically is used to ablate heart tissue during a coronary artery bypass surgery or mitral valve surgery, but also can be used in minimally invasive, closed-chest procedures.

Guidant acquired the Flex technology via its acquisition of AFx (Fremont, California) in February 2004 (Medical Device Daily, Feb. 11, 2004)

Cleared by the FDA, the system has been used in more than 8,000 procedures worldwide. In March, the device received the CE mark specifically for the treatment of AF, in addition to other cardiac ablation uses.

A Guidant spokesperson told Medical Device Daily that while the Flex system does have a general approval for “surgical ablation of cardiac tissue,” the company is pursuing individual ablation clearances, including the important AF market.

“Guidant’s sponsorship of the RESOLVE-AF trial demonstrates our commitment to atrial fibrillation therapy,” said Maria Degois-Sainz, president of Guidant’s Cardiac Surgery business, in a company statement. “We are pleased to partner with leading institutions in the cardiac surgery community to develop treatments for this disabling and life-threatening condition. Guidant’s new treatments for atrial fibrillation, including surgical ablation and implantable cardioverter defibrillator therapies, are critical components of our larger heart failure strategy and our continued efforts to improve patients’ lives and clinical outcomes.”

The Guidant spokesperson noted additional criteria for the study, saying that patients would be followed for six months.

The primary trial endpoints include composite major adverse event rate at one month and freedom from AF at six months. Secondary endpoints include composite major adverse event rate at three and six months, restoration of normal sinus rhythm at discharge, change in cardiac function at six months, and change in quality of life at six months.

The spokesperson said that patients would be randomized to either treatment or control groups. Control patients will not receive the ablation treatment but will receive their scheduled mitral valve surgery. Randomization will be 1:1 (100 patients in the treatment group and 100 patients in the control group).

“Microwave ablation shows great promise for treating permanent atrial fibrillation, which affects as many as two-thirds of all atrial fibrillation patients,” said Michael Mack, MD, director of transplantation at Medical City Dallas Hospital (Dallas) a cardiovascular/thoracic surgeon and principal investigator of the trial. “I am enthusiastic about the potential of this therapy, which may help expand the treatment options for patients suffering from this condition.”

AF is a heart arrhythmia that causes the atria to quiver, preventing the atria from effectively pumping blood into the lower chambers of the heart and reducing pumping efficiency.

More than 2.4 million patients in the U.S. suffer from atrial fibrillation, and its prevalence is expected to double in the next 40 years. The condition can cause heart failure or complicate its effective treatment, and also is associated with reduced quality of life, higher medical costs, and a five-fold increase in the risk of stroke. In about 50% of AF patients, drug therapy is ineffective or causes severe side effects, making therapies, such as surgical ablation, increasingly valuable, the company said.

In another event reported last week, Guidant said that it has begun enrollment in its SPIRIT II drug-eluting stent (DES) clinical study.

SPIRIT II is a 300-patient study evaluating the Xience V, an everolimus-eluting coronary stent system using Guidant’s cobalt chromium Multi-Link Vision coronary stent system platform.

This single-blind, randomized controlled study further evaluates the Xience V compared to Boston Scientific’s (Natick, Massachusetts) Taxus Express2 paclitaxel-eluting coronary stent system for the treatment of coronary artery disease.

Results of the SPIRIT II study will provide additional clinical data to support the launch of Xience V in several countries outside the U.S. the company said.

“SPIRIT II will provide additional important data about drug-eluting stents for the treatment of coronary artery disease, a growing cause of disability around the world,” said John Capek, PhD, president of Guidant’s Vascular Intervention business.

The first patient was enrolled by Gert Richardt, MD, of Segeberger Kliniken (Bad Segeberg, Germany). “I am enthusiastic about the potential of the Xience V everolimus-eluting stent system for the treatment of coronary artery disease,” Richardt said in a statement.

Guidant disclosed last month the U.S. initiation of SPIRIT III, a large-scale pivotal clinical trial evaluating Xience V, a study which may be used to obtain FDA approval for the system for the treatment of coronary artery disease (MDD, June 24, 2005).

The company, which has lagged behind competitors in the DES space, first entered the U.S. market in February 2004 through an agreement with Cordis (Miami Lakes, Florida) a Johnson & Johnson (J&J; New Brunswick, New Jersey) company.

Under the terms of the agreement, Guidant co-promotes Cordis’ Cypher sirolimus-eluting coronary stent in the U.S.

J&J has agreed to buy Guidant for $25.4 billion in a deal expected to close by September. However, given recent recalls and potential litigation involving Guidant’s ICDs, it remains to be seen what, if any, effect those actions will have on the deal.

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