EnteroMedics Therapy Fails to Meet Weight-Loss Study Goal

EnteroMedics Inc. said its implanted nerve-blocking therapy failed to help patients lose as much weight as intended in a key obesity study. The company’s shares lost almost two-thirds of their value in extended trading.

The VBLOC vagal blocking therapy helped 53 percent of patients shed at least 20 percent of their excess weight, compared with 33 percent of volunteers in whom the device was implanted but not turned on, the company said today in a statement. The difference in weight loss, 24 percent in treated patients and 16 percent in untreated patients, didn’t meet the predetermined “super superiority” goal in the study involving 239 people, the St. Paul, Minnesota-based company said.

The device clearly had a positive effect on weight loss, even though it didn’t meet the effectiveness goals, said Chief Executive Officer Mark Knudson. EnteroMedics plans to file for U.S. Food and Drug Administration approval of the technique in the second quarter of 2013, he said.

“Based on these compelling results, and the totality of our clinical experience with the Maestro System, which now includes more than 600 patients worldwide, we believe EnteroMedics is well positioned to deliver this novel therapy to people with obesity in the U.S.,” Knudson said.

EnteroMedics shares declined 65 percent to $1 at 4:35 p.m. New York time in extended trading, after falling 4.7 percent to $2.84 at the close. The company had gained 22 percent in the past 12 months.

The Maestro Rechargeable System is a less-invasive method than surgery to help obese people lose weight, the company said. The device is attached by two small electrodes to the trunk of the vagus nerve between the esophagus and the stomach. The device uses high-frequency, low-energy electrical impulses to reduce feelings of hunger.