By HOLLAND JOHNSON Medical Device Daily Senior Staff Writer
A permanent implant that can free many patients from taking daily medications to fight acid reflux won approval from the FDA late Tuesday.
Enteryx, made by Boston Scientific (Natick, Massachusetts), is a liquid solution, containing a polymer and a solvent, which solidifies into a permanent sponge-like material after being injected into the muscular valve between the esophagus and stomach, an area called the lower esophageal sphincter (LES).
The purpose is to reinforce the valve that is supposed to keep stomach acid from flowing into the throat.
The FDA cleared Enteryx for treating gastroesophageal reflux disease (GERD), which causes frequent heartburn. More than 60 million American adults experience GERD, and about 25 million of them have daily symptoms, the FDA said. Specifically, Enteryx was approved for use in patients who have GERD symptoms and who require and respond to proton pump inhibitors (PPI).
The FDA\'s Gastroenterology and Urology Devices Panel recommended unanimous approval of the system at a meeting in January, although some members expressed concern that the patients in the clinical trial were only followed for one year (Medical Device Daily, Jan. 22, 2003).
Conditions for approval recommended by the panel included a statistical analysis of longitudinal effects of the device, assessment of the need for guidelines on re-treatment of patients, and including patients with esophageal strictures in the precautionary list of patients in the device\'s labeling.
Enteryx has been available in some European countries for more than two years. And Boston Scientific acquired the system when it purchased Enteric Medical Technologies (Foster City, California) last year (MDD, June 14, 2003). The company now is part of Boston Sci\'s Endosurgery group.
"The device has been found to help eliminate or reduce the need for medications, and to improve the symptoms of GERD," the FDA said in a statement.
In a 12-month study of 85 patients, about 67% of the patients were able to discontinue use of medications known as proton pump inhibitors, and 9% could reduce the dose by at least half, the FDA said. Close to 72% of the patients in the study said their symptoms improved when compared with taking no medications prior to the implant.
The device is implanted by injection during an X-ray guided endoscopic procedure into the wall of the LES. After the injection, the solvent separates away and the polymer solidifies into a spongy material that is intended to help prevent the reflux.
While the FDA said many patients had improvements in their symptoms and medication requirements, it noted that objective evaluations of the esophagus performed during the clinical trial showed evidence of persistent acid reflux in 61% of patients and low-grade inflammation in 37% of patients at 12 months.
While the approval is a positive, some questions remain as to the true market potential of the device. The maker said it hopes the device will appeal to GERD patients who want to reduce or eliminate medication use but do not want to have anti-reflux surgery, according to Michael Phalen, president of Boston Scientific\'s endoscopy unit.
"The space we are trying to occupy is somewhere between pharmacological intervention and surgery...We think the market is going to be very receptive to [Enteryx]," he said.
The company estimates that 15 million people in the U.S. are taking proton pump inhibitors for GERD and that between 10% and 15% of those may be candidates for a device such as Enteryx, Phalen told MDD. He added that the entire procedure takes between 30 and 45 minutes to perform.
On the Medicare reimbursement front, the company still has a ways to go, Phalen said. "We are going to work on it. This is a procedure that will require lots of data for submission for adequate levels of reimbursement."
While he would not comment directly on sales projections or specific costs for the procedure, he estimated that the average yearly cost per patient for PPIs in the U.S. is between $1,500 and $2,000. \"So, depending upon the efficacy of our implant over time, [Enteryx] will affect the whole cost economic curve.\"
The most common side effect observed during the company's study was pain beneath the breastbone that usually diminished within two weeks, the FDA said. Other common side effects included temporary difficulty with swallowing, fever and sore throat.
The device should not be used in people who are unable to undergo endoscopy, or who have dilated veins in the esophagus due to liver disease.
Medical Device Daily, April 24, 2003