EnteroMedics CEO Offers Explanation for Failed Obesity Trial

EnteroMedics Inc., the St. Paul, MN manufacturer of neuromodulation systems for treatment of obesity, offered follow-up information on the company’s recently completed Empower study of vagus nerve block for treatment of obesity, which failed to meet its efficacy endpoints.

Speaking at the J.P. Morgan Healthcare Conference earlier this month [see conference report, p7], EnteroMedics CEO Mark Knudson noted that both treatment and control groups achieved 23 percent excess weight loss after 12 months using the implanted Maestro device. Knudson suspects a failure in the device’s control mode, which produced an unanticipated effect of the low-charge impedance, safety, and diagnostic checks in the control arm. “Both arms had essentially the same effect,” Knudson said.

As evidence for this, Knudson showed data comparing subjects who used the device more than nine hours per day compared to those who used it less than nine hours per day. In both the treatment and control groups, the subjects who used the device more than nine hours per day showed a significantly greater excess weight loss.

EnteroMedics is developing better clinical models to understand compound action potentials during block. Knudson believes the control mode effect is cumulative over time, rather than instantaneous.
The company plans to meet with FDA officials in coming weeks to discuss its options for bringing the device to market. EnteroMedics is also conducting an Enable trial for treating diabetes in five centers outside the U.S. using its new RC2 rechargeable system.