FDA Panel Backs Reflux Disease Implant
Minimally Invasive Procedure Provides Alternative to Drugs, Surgery
Jan. 21, 2003 -- A newly developed implant could offer relief to sufferers of stomach acid reflux disease. The Enteryx implant would be the first FDA-approved alternative to drugs or surgery.
Most people experience heartburn at some point in their lives. However, when stomach acid frequently backs up into the esophagus, the condition is called gastroesophageal reflux disease (GERD). When taken daily, drugs such as Nexium and Prevacid stop acid production and prevent symptoms and damage to the esophagus. But when the drugs fail or when the cost and trouble of daily medication becomes burdensome, many people look for alternatives.
Think you might have GERD? See this list of symptoms.
The Enteryx implant consists of a polymer that is injected into the muscle -- called the esophageal sphincter -- that normally controls the passageway from the esophagus to the stomach. In GERD, this muscle malfunctions, leading to frequent heartburn symptoms. Once injected, the polymer quickly forms a small mass that appears to reinforce the barrier, according to officials from Enteric Medical Technologies, Enteryx's manufacturer.
GERD can already be treated with several kinds of drugs and surgery. That sets a "pretty high bar" for any new treatment, says Nicholas Shaheen, MD, assistant professor of medicine and epidemiology at the University of North Carolina, and a member of the FDA panel that recommended approval of the device.
But the implant -- tested in 85 people on drugs to treat GERD -- is far less invasive than surgery. And among the participants in the study -- sponsored by Enteric -- side effects, most commonly chest pain and difficulty swallowing, were temporary and readily treated.
The procedure to implant Enteryx typically takes less than an hour. A doctor inserts a tube through a patient's mouth into the esophagus, and injects the liquid polymer into the muscle between the esophagus and stomach. The liquid solution then forms into a sponge-like material.
The company wanted to find out if the implant could successfully replace drugs, allowing patients to reduce or eliminate medication altogether. After six months, they found that 74% of patients completely stopped their daily medication, while another 10% had reduced their doses. Overall, 56% of patients went off all medications entirely, including over-the-counter antacid tablets.
"Some patients can't tolerate the medicine or they don't like it. This is an alternative," says David Johnson, MD, professor of medicine at Eastern Virginia Medical School, and a consultant to Enteric.
Still, FDA officials question how long the effects of the implant will last, citing evidence that the polymer implant eroded over time. The committee recommended as a condition of approval that the company investigate the question in the post-marketing clinical trials that it will conduct.
"I think we should not view it as permanent, but we've seen with a single injection and a well-defined population that there is a short-term benefit," says Brian Fennerty, MD, professor of gastroenterology at Oregon Health Sciences University and a member of the FDA panel.
For now, the panel recommends that the implant be approved only for patients that have not been able to control their disease with drugs. If further tests show that it is effective in the long term, it may get broader approval.
The FDA is not required to heed the advice of its advisory panels, but it usually does.