Intra-abdominal vagal nerve blockade to treat morbid obesity didn’t meet prespecified efficacy objectives in the randomized, double-blind ReCharge study, but treated patients did experience significantly greater weight loss than did those who underwent a sham procedure.
Mean excess weight loss was 24.4% (9.2% of initial body weight loss) in 162 patients who had a body mass index of 40-45 kg/m2 or 35-40 kg/m2 plus one or more obesity-related conditions, who underwent vagal nerve block therapy, compared with 15.9% (6% of initial body weight loss) in 77 patients in the sham group, for a mean between-group difference of 8.5 percentage points.
The difference was statistically significant, but it was less than the prespecified 10-point superiority margin, Dr. Sayeed Ikramuddin of the University of Minnesota, Minneapolis, and colleagues reported online Sept. 2 in JAMA.
At 12 months, 20% or more excess weight loss was achieved by 52% of patients in the vagal nerve block group, compared with 32% of patients in the sham procedure group. A total of 25% or more excess weight loss was achieved by 38% and 23% of patients in the groups, respectively, the investigators said (JAMA 2014;312:915-22).
Patients in the treatment group experienced more heartburn and dyspepsia, abdominal and other nonspecific pain, dysphagia, nausea, and eructation or belching than those in the control group. But these side effects were generally mild or moderate in severity. Serious adverse events associated with vagal nerve blockade occurred in 3.7% of treatment group patients, which was well below the 15% upper threshold for safety in the trial.
Additional study is needed to compare vagal nerve block with other obesity treatments, and to assess long-term durability and safety of the procedure, the investigators concluded.
This study was supported by EnteroMedics, which makes the vagal nerve blockade device used in the study. Dr. Ikramudden reported serving on the advisory board for Novo Nordisk and Medica, serving as a consultant for Metamodix and on an expert panel for OptumHealth, and receiving grant support from USGI Medical, ReShape Medical, and Covidien.