Trial · NCT00567255

A Safety and Efficacy Study of Naltrexone SR/Bupropion SR in Overweight and Obese Subjects

NCT00567255, Phase 3, Completed, Orexigen Therapeutics, Inc; results first posted 2014-11-21

3 sourcestrials-2026-11-12-0.5.0

Cite this record

ConductScience Library. A Safety and Efficacy Study of Naltrexone SR/Bupropion SR in Overweight and Obese Subjects. Trials, record NCT00567255. Release trials-2026-11-12-0.5.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT00567255

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Trial

As registered on ClinicalTrials.gov, in the graph's capture of the registry.

Title: A Safety and Efficacy Study of Naltrexone SR/Bupropion SR in Overweight and Obese Subjects
NCT number: NCT00567255
Status: Completed
Phases: Phase 3
Enrollment: 1,496 participants, actual
Lead sponsor: Orexigen Therapeutics, Inc
Conditions: Obesity, Overweight
Interventions: Naltrexone SR 32 mg/bupropion SR 360 mg/day, Placebo, Ancillary therapy
First posted: 2007-12-04
Last updated: 2014-11-21
Results first posted: 2014-11-21

Source ClinicalTrials.gov

Registered outcomes20

Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.

List	Outcome	Time frame	Description
Primary	Co-primary: Body Weight- Mean Percent Change From Baseline to Week 28	Baseline, 28 weeks
Primary	Co-primary: Body Weight- Proportion of Subjects With ≥5% Decrease From Baseline to Week 28	Baseline, 28 weeks
Secondary	Body Weight- Mean Percent Change From Baseline to Week 56	Baseline, 56 weeks	Beginning at Week 28 through Week 44, NB32-treated subjects who failed to achieve or maintain at least 5% body weight loss from baseline were re-randomized (1:1 ratio) to continue NB32 or begin treatment with a higher dose of naltrexone SR - naltrexone SR 48 mg/bupropion SR 360 mg (referred to as NB48) (daily dose of bupropion SR was 360 mg for NB32 and NB48).The analysis of NB32 vs. placebo at Week 56 was completed using a weighted analysis. This analysis was referred to as the weighted LOCF analysis. Subjects treated with NB32 who were re-randomized to NB48 were not included. Subjects re-randomized to NB32 were double-weighted and subjects who were not re-randomized were single-weighted. Subjects in the placebo group were single-weighted. The double weighting analysis restored the influence of poor performers at Weeks 28 to 44 in the NB32 group without including any data from the higher dose group (NB48).
Secondary	Body Weight- Proportion of Subjects With ≥5% Decrease From Baseline to Week 56	Baseline, 56 weeks	Beginning at Week 28 through Week 44, NB32-treated subjects who failed to achieve or maintain at least 5% body weight loss from baseline were re-randomized (1:1 ratio) to continue NB32 or begin treatment with a higher dose of naltrexone SR - naltrexone SR 48 mg/bupropion SR 360 mg (referred to as NB48) (daily dose of bupropion SR was 360 mg for NB32 and NB48).The analysis of NB32 vs. placebo at Week 56 was completed using a weighted analysis. This analysis was referred to as the weighted LOCF analysis. Subjects treated with NB32 who were re-randomized to NB48 were not included. Subjects re-randomized to NB32 were double-weighted and subjects who were not re-randomized were single-weighted. Subjects in the placebo group were single-weighted. The double weighting analysis restored the influence of poor performers at Weeks 28 to 44 in the NB32 group without including any data from the higher dose group (NB48).
Secondary	Body Weight- Proportion of Subjects With ≥10% Decrease From Baseline to Week 28	Baseline, 28 weeks
Secondary	Change in Waist Circumference	Baseline, 28 weeks
Secondary	Change in Fasting HDL Cholesterol Levels	Baseline, 28 weeks
Secondary	Change in Fasting Triglycerides Levels, Using Log-transformed Data	Baseline, 28 weeks
Secondary	Change in IWQOL-Lite Total Scores	Baseline, 28 weeks	IWQOL-Lite= Impact of Weight on Quality of Life-Lite Questionnaire Total score is based on a scale from 0 to 100, with 0 representing the poorest and 100 the best quality of life and where a score of 71-79 indicates moderate impairment
Secondary	Change in High-sensitivity C Reactive Protein (Hs-CRP) Levels, Using Log-transformed Data	Baseline, 28 weeks

1 to 10 of 20Source ClinicalTrials.gov

See all 20 registered outcomes

Outcomes20

Each outcome the trial posted results for, in ClinicalTrials.gov's words.

Type	Outcome	Time frame	Population	Units	Measured as
PRIMARY	Co-primary: Body Weight- Mean Percent Change From Baseline to Week 28	Baseline, 28 weeks	Modified ITT (Full Analysis Set): Included all subjects who were randomized, had a baseline weight measurement, and had at least one post-baseline weight measurement while on study drug. Missing data were imputed with the LOCF method.	percentage of body weight	LEAST_SQUARES_MEAN
SECONDARY	Body Weight- Mean Percent Change From Baseline to Week 56	Baseline, 56 weeks	Modified ITT: Included all subjects who were randomized, had a baseline weight measurement, and had at least one post-baseline weight measurement while on study drug. Missing data were imputed with the LOCF method.	percentage of body weight	LEAST_SQUARES_MEAN
PRIMARY	Co-primary: Body Weight- Proportion of Subjects With ≥5% Decrease From Baseline to Week 28	Baseline, 28 weeks	Modified ITT: Included all subjects who were randomized, had a baseline weight measurement, and had at least one post-baseline weight measurement while on study drug. Missing data were imputed with the LOCF method.	percentage of participants	NUMBER
SECONDARY	Body Weight- Proportion of Subjects With ≥5% Decrease From Baseline to Week 56	Baseline, 56 weeks	Modified ITT: Included all subjects who were randomized, had a baseline weight measurement, and had at least one post-baseline weight measurement while on study drug. Missing data were imputed with the LOCF method.	percentage of participants	NUMBER
SECONDARY	Body Weight- Proportion of Subjects With ≥10% Decrease From Baseline to Week 28	Baseline, 28 weeks	Modified ITT: Included all subjects who were randomized, had a baseline weight measurement, and had at least one post-baseline weight measurement while on study drug. Missing data were imputed with the LOCF method.	percentage of participants	NUMBER
SECONDARY	Change in Waist Circumference	Baseline, 28 weeks	Modified ITT: Included all subjects who were randomized, had a baseline weight measurement, and had at least one post-baseline weight measurement while on study drug. Missing data were imputed with the LOCF method.	cm	LEAST_SQUARES_MEAN
SECONDARY	Change in Fasting HDL Cholesterol Levels	Baseline, 28 weeks	Modified ITT: Included all subjects who were randomized, had a baseline weight measurement, and had at least one post-baseline weight measurement while on study drug. Missing data were imputed with the LOCF method.	mg/dL	LEAST_SQUARES_MEAN
SECONDARY	Change in Fasting Triglycerides Levels, Using Log-transformed Data	Baseline, 28 weeks		percent change	LEAST_SQUARES_MEAN
SECONDARY	Change in IWQOL-Lite Total Scores	Baseline, 28 weeks	Modified ITT: Included all subjects who were randomized, had a baseline weight measurement, and had at least one post-baseline weight measurement while on study drug. Missing data were imputed with the LOCF method.	units on a scale	LEAST_SQUARES_MEAN
SECONDARY	Change in High-sensitivity C Reactive Protein (Hs-CRP) Levels, Using Log-transformed Data	Baseline, 28 weeks	Modified ITT: Included all subjects who were randomized, had a baseline weight measurement, and had at least one post-baseline weight measurement while on study drug. Missing data were imputed with the LOCF method.	percent change	LEAST_SQUARES_MEAN

1 to 10 of 20Source ClinicalTrials.gov

See all 20 outcomes

Results by group40

Each measurement the trial posted, group by group, in the words and numbers it posted.

Outcome	Group	Value	Spread	Units
Co-primary: Body Weight- Mean Percent Change From Baseline to Week 28	NB32	-6.45	Standard Error 0.20	percentage of body weight
Co-primary: Body Weight- Mean Percent Change From Baseline to Week 28	Placebo	-1.89	Standard Error 0.26	percentage of body weight
Body Weight- Mean Percent Change From Baseline to Week 56	NB32	-6.40	Standard Error 0.25	percentage of body weight
Body Weight- Mean Percent Change From Baseline to Week 56	Placebo	-1.23	Standard Error 0.33	percentage of body weight
Co-primary: Body Weight- Proportion of Subjects With ≥5% Decrease From Baseline to Week 28	NB32	55.64	95% Confidence Interval 52.25 to 59.03	percentage of participants
Co-primary: Body Weight- Proportion of Subjects With ≥5% Decrease From Baseline to Week 28	Placebo	17.54	95% Confidence Interval 14.05 to 21.03	percentage of participants
Body Weight- Proportion of Subjects With ≥5% Decrease From Baseline to Week 56	NB32	50.48	95% Confidence Interval 46.90 to 54.07	percentage of participants
Body Weight- Proportion of Subjects With ≥5% Decrease From Baseline to Week 56	Placebo	17.11	95% Confidence Interval 13.46 to 20.75	percentage of participants
Body Weight- Proportion of Subjects With ≥10% Decrease From Baseline to Week 28	NB32	27.27	95% Confidence Interval 24.23 to 30.31	percentage of participants
Body Weight- Proportion of Subjects With ≥10% Decrease From Baseline to Week 28	Placebo	7.02	95% Confidence Interval 4.67 to 9.36	percentage of participants

1 to 10 of 40Source ClinicalTrials.gov

See all 40 results by group

Participant flow6

How many started, completed or left each group, period by period.

Period	Milestone	Group	Participants
Overall Study	STARTED	NB32	1,001
Overall Study	STARTED	Placebo	495
Overall Study	COMPLETED	NB32	538
Overall Study	COMPLETED	Placebo	267
Overall Study	NOT COMPLETED	NB32	463
Overall Study	NOT COMPLETED	Placebo	228

Source ClinicalTrials.gov

Adverse events90

Each adverse event the trial posted, group by group: the participants affected out of those at risk.

Type	Event	Organ system	Group	Affected	At risk	Events
other	Constipation	Gastrointestinal disorders	NB32/48	189	992	199
other	Constipation	Gastrointestinal disorders	Placebo	35	492	36
other	Diarrhoea	Gastrointestinal disorders	NB32/48	55	992	57
other	Diarrhoea	Gastrointestinal disorders	Placebo	18	492	21
other	Dry mouth	Gastrointestinal disorders	NB32/48	90	992	91
other	Dry mouth	Gastrointestinal disorders	Placebo	13	492	13
other	Nausea	Gastrointestinal disorders	NB32/48	290	992	329
other	Nausea	Gastrointestinal disorders	Placebo	34	492	41
other	Vomiting	Gastrointestinal disorders	NB32/48	84	992	95
other	Vomiting	Gastrointestinal disorders	Placebo	10	492	10

1 to 10 of 90Source ClinicalTrials.gov

See all 90 adverse events

Adverse event totals6

The totals the trial posted for each group.

Total	Group	Affected	At risk
Total, all-cause mortality	NB32/48
Total, all-cause mortality	Placebo
Total, other adverse events	NB32/48	671	992
Total, other adverse events	Placebo	244	492
Total, serious adverse events	NB32/48	21	992
Total, serious adverse events	Placebo	7	492

Source ClinicalTrials.gov

Papers1

The papers the trial lists on ClinicalTrials.gov.

PMID	Listed as
23408728	RESULT

Source PubMed

Grants0

The grants NIH RePORTER links to the trial, newest funded first: NIH's, and some of AHRQ's, CDC's, FDA's and VA's. Each shows its title, principal investigators, organization and funder in its newest year.

None in this release.

Trial comparisons1

Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.

Comparison
NB32/48 vs Placebo: serious adverse events

Source Trial comparisons

Tests0

The ConductCognition tests this trial's registered outcomes name, as ScienceGraph matched them in trial-tests-2026-11-12-0.2.1.

None in this release.

Data dates

The day each source was copied for this release.

ClinicalTrials.gov: 2026-11-12; ClinicalTrials.gov
Results, from AACT: 2026-03-23; AACT
NIH grant links: 2026-11-13; NIH RePORTER

Sources 3

ClinicalTrials.gov's posted results, through CTTI's AACTFreely available. Acknowledgement requested
ClinicalTrials.govNo license stated
NIH RePORTER's clinical studies and project filesPublic domain

Each source's terms

ClinicalTrials.gov's posted results, through CTTI's AACTClinicalTrials.gov data via Aggregate Analysis of ClinicalTrials.gov (AACT), CTTI. CTTI makes its materials freely available and requests acknowledgement. https://aact.ctti-clinicaltrials.org/documentation/299
ClinicalTrials.govnone stated
NIH RePORTER's clinical studies and project filesPublic domain (NIH RePORTER)

ClinicalTrials.gov's data carry an international copyright outside the United States: https://clinicaltrials.gov/about-site/terms-conditions.

For software

Read this trial from software.

The record and each of its lists are JSON, twenty rows a page. No key.

GET https://conductscience.org/api/trials/v1/NCT00567255

GET https://conductscience.org/api/trials/v1/NCT00567255/results?page=2

API reference For AI assistants