A growing number of treatments for the common condition known as gastroesophageal reflux disease (GERD) have been developed over the past five years, but what if GERD has moved on to the precancerous condition?
That is the unhappy situation – presenting as a disease known as Barrett’s esophagus – being addressed by Barrx Medical (Sunnyvale, California), which this week reported four studies delivered at the Digestive Disease Week (DDW) 2005 meeting in Chicago, demonstrating the potential benefits of the company’s Halo360 system.
Thus far, “there is no effective treatment for Barrett’s esophagus,” Virender Sharma, MD, told Medical Device Daily, but adding that the studies presented indicate early stage hope for use of the Halo360 as a cure. Sharma, director of the esophageal clinic and associate professor of medicine at the Mayo Clinic (Scottsdale, Arizona), termed the data from all three studies “encouraging” and that they lay key groundwork supporting the device’s early term efficacy.
The Halo360 provides ablation of abnormal cell development in the lining of the esophagus – termed dysplasia and characterized by Sharma as “chaotic” – which is primarily the result of acid reflux. The device delivers rapid bursts of radio frequency (RF) energy that kill the abnormal cells.
Sharma terms the device’s method of action as “a flash burn [that] doesn’t translate to heat but serves to destroy the cells.” Then, he says, “if you kill these cells and let them heal back, with strong acid control, the lining comes back as normal.” And thus far, he and his research team have not seen the return of precancerous cells indicating Barrett’s or problems with underlying cell tissues.
The three trials presented are all different in procedure and endpoint:
• The Ablation of Intestinal Metaplasia (AIM-I) trial, with treatment of 31 patients, focused on the safety and tolerability of the Halo360. Delivering 10 joules of energy, its goal is to explore appropriate dosing for ablating short segments of Barrett’s.
It found that at six months 75% of patients from the treatment group had no Barrett’s tissue cells. Additionally, there were no complications or findings of abnormal “buried” glands that may produce disease recurrence.
Sharma noted that the other 25% of the group had “90%-plus of Barett’s esophagus removed.”
• Results of the AIM-II multi-center trial, evaluating treatment of 70 patients, was presented by David Fleischer, MD, also of the Scottsdale Mayo Clinic. This trial employed 12 joules of RF energy, with the majority of patients having no evidence of Barrett’s tissue on follow-up. And those patients with persistent disease experienced significant reduction in their Barrett’s and remained eligible for retreatment. Follow-up tests revealed no strictures or buried glands, Fleischer reported.
The researchers concluded “that the safe removal of Barrett’s esophagus in a single treatment is achievable” with the Halo360.
• The third study presented the evaluation of patients with low-grade dysplasia, a more advanced stage of Barrett’s esophagus. Sharma reported an 80% patient response rate after just one treatment “at a slightly higher energy dose than that applied in the AIM trials.”
He reported that with a second treatment, the cure rate at six months increased to 100%. The data suggest that the Halo360 system can safely and effectively eliminate low-grade dysplasia in patients with Barrett’s esophagus, he said.
C. Daniel Smith, MD, of Emory University School of Medicine (Atlanta), presented still another study evaluating the optimal parameters for the ablation of Barrett’s esophagus with high-grade dysplasia. This study found that the complete ablation of esophageal high-grade dysplasia is possible without causing injury to the healthy underlying tissue.
“This is not a treatment for GERD,” Sharma emphasized, but rather for the more serious consequences of GERD.
Other systems for treating the precancerous condition of Barrett’s have been “point-and-shoot devices,” he said, and he described them as inadequate and “cumbersome” and having a variety of complications. By contrast, he pointed to the safety and efficacy of the Halo, while underlining its procedural benefits.
The system’s generator, he said, is “a neat thing that controls the whole treatment [and] takes the human factor out of [the procedure]. You step on a button [to treat] three centimeters length of Barrett’s in less than a second.”
The procedure, which in clinical studies had an average procedure time of 26 minutes, is performed without incisions, using conscious sedation in an outpatient setting.
The next step in the research, Sharma said, will be to collect longer-term data concerning use of the Halo360, including a pilot multi-center trial evaluating the treatment of low-grade dysplasia with the device as compared to the standard therapy using acid-suppressing medications. He expects this trial will include 70 to 100 patients, with evaluation over a two-year period.
Barrx, specifically founded to develop solutions for Barrett’s esophagus, estimates 1 to 2 million adults in the U.S. under surveillance of their acid reflux – essentially a strategy of watching and waiting.
DDW – jointly sponsored by the American Association for the Study of Liver Diseases, the American Gastroenterological Association, the American Society for Gastrointestinal Endoscopy and the Society for Surgery of the Alimentary Tract – is billed as the largest international gathering of physicians, researchers and academics in the fields of gastroenterology, hepatology, endoscopy and gastrointestinal (GI) surgery.
The meeting is showcasing about 5,000 abstracts and hundreds of presentations on advances in GI research and technology.