Naltrexone SR/Bupropion SR Combination Therapy Reduces Total and Visceral Adiposity in Overweight and Obese Subjects in the COR-I Study
Abstract Number: 1848-P
Authors: STEVEN R. SMITH, TIMOTHY CHURCH, JEFFREY GEOHAS, CARL GRIFFIN, WAYNE L. HARPER, DIANE KRIEGER, JUDY F. LOPER, SUNDER MUDALIAR, CHIVERS WOODRUFF, MARIA GUTTADAURIA, EUGENIA HENRY, DENNIS D. KIM, EDUARDO DUNAYEVICH
Institutions: Baton Rouge, LA, Chicago, IL, Oklahoma City, OK, Raleigh, NC, Miami, FL, Columbus, OH, San Diego, CA, Birmingham, AL, New York, NY, Hunt Valley, MD, La Jolla, CA
Results: The COR-I body composition substudy was conducted in a subset of subjects (N=214) of COR-I, a Phase 3, randomized, double-blind, placebo-controlled, 56-week study examining the efficacy and safety of two doses of naltrexone sustained release (SR)/bupropion SR for the treatment of obesity. Subjects (N=1742) were randomized 1:1:1 to receive oral NB32 (32 mg naltrexone/360 mg bupropion daily), NB16 (16 mg naltrexone/360 mg bupropion daily) or placebo (PBO). A subset of subjects (N=214) had DEXA scans at baseline and Week 52 to assess effects of NB therapy on body composition. Of these, 116 subjects also had multi-slice abdominal CT scans to assess the effect of NB on visceral adiposity and hepatic lipid content. Data analyses were conducted on the pooled NB group (NB32- and NB16-treated subjects) vs. PBO. Substudy baseline characteristics were similar to the parent study: age 44y, 86% female, 68% Caucasian, weight 98±14 kg, BMI 36±4 kg/m2, waist circumference 109±10 cm, total body adipose tissue mass 41±8 kg, body fat percentage 42±6%, visceral adipose mass 4.0±1.7 kg. 53% of subjects had a baseline and Week 52 DEXA or DEXA/CT scan. Among these subjects, weight loss in the NB group was greater (-7.2±0.9%; N=79) than in the PBO group (-2.1±1.1%; N=45) (P<0.001). The reduction in total body adipose tissue mass was significantly greater with NB (-4.7±0.6 kg; -11.7±1.5%) than PBO (-1.4±0.8 kg; 4.3±1.9%; P<0.01). The change in percent body fat was -2.4±0.4% with NB and -0.8±0.5 with PBO (P<0.01). NB reduced waist circumference (-5.8±1.0 cm vs. -2.3±1.3 cm; P<0.05) and visceral adipose mass (-0.6±0.1 kg [-14.8±3.6%] vs. -0.2±0.1 kg [-5.0±4.0%] P<0.05). Liver fat was reduced with NB (3.3±0.9 HU) vs. PBO (0.6±1.0 HU) (P<0.05). In subjects who experienced at least 4% weight loss, 70-76% of weight loss was adipose tissue, indicating that weight loss with NB was not due to excess loss of lean mass. In summary, NB treatment reduced body weight as well as total and visceral adiposity and hepatic lipid content.