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A Study Comparing Multiple Doses of VI-0521 With Placebo and Their Single-agent Constituents for Treatment of Obesity in Adults

This study has been completed.
Medpace, Inc.
Information provided by (Responsible Party):
VIVUS, Inc. Identifier:
First received: November 21, 2007
Last updated: March 10, 2015
Last verified: March 2015
The objective of this study is to evaluate the safety and efficacy of various doses of VI-0521 compared to both placebo, and the single-agent components that comprise each combination dose. This study will provide confirmatory data to demonstrate that doses of VI-0521 have efficacy that is greater than placebo and each of the single-agent components that comprise the combination dose.

Condition Intervention Phase
Drug: VI-0521
Drug: topiramate
Drug: phentermine
Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: A Phase III, Randomized, Double-Blind, Parallel-Design Study Comparing Multiple Doses of VI-0521 to Placebo and Their Single-Agent Phentermine and Topiramate Constituents for the Treatment of Obesity in Adults

Resource links provided by NLM:

Further study details as provided by VIVUS, Inc.:

Primary Outcome Measures:
  • Percent Weight Loss From Baseline to Week 28 [ Time Frame: baseline to 28 weeks ]
    Percent weight loss from baseline to Week 28 with last observation carried forward (LOCF)

  • Percentage of Subjects With at Least 5% Weight Loss at Week 28 With LOCF [ Time Frame: baseline to 28 weeks ]

Enrollment: 756
Study Start Date: December 2007
Study Completion Date: September 2008
Primary Completion Date: September 2008 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: VI-0521 Top
VI-0521; high dose phentermine/topiramate
Drug: VI-0521
phentermine 15 mg and topiramate 92 mg, po once daily
Experimental: VI-0521 Mid
VI-0521; mid dose phentermine/topiramate
Drug: VI-0521
phentermine 7.5 mg and topiramate 46 mg, po once daily
Active Comparator: TPM 46
mid dose topiramate
Drug: topiramate
topiramate 46 mg, po once daily
Active Comparator: TPM 92
high dose topiramate
Drug: topiramate
topiramate 92 mg, po once daily
Active Comparator: PHEN 7.5
mid dose phentermine
Drug: phentermine
phentermine 7.5 mg, po once daily
Active Comparator: PHEN 15
high dose phentermine
Drug: phentermine
phentermine 15 mg, po once daily
Placebo Comparator: Placebo Drug: VI-0521
placebo, po once daily


Ages Eligible for Study:   18 Years to 70 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • 70 years of age or less with body mass index (BMI) between 30 and 45 kg/m2
  • Informed Consent
  • Females of child-bearing potential must be using adequate contraception

Exclusion Criteria:

  • Stroke/myocardial infarction (MI)/unstable cardiovascular disease within 6 months
  • Clinically significant renal, hepatic or psychiatric disease
  • Unstable thyroid disease or replacement therapy
  • Nephrolithiasis
  • Obesity of known genetic or endocrine origin
  • Participation in a formal weight loss program or lifestyle intervention
  • Glaucoma or elevated intraocular pressure
  • Pregnancy or breastfeeding
  • Drug or Alcohol abuse
  • Smoking cessation within previous 3 months or plans to quit smoking during study
  • Eating disorders within past year
  • Cholelithiasis within past 6 months
  • Type 2 diabetes
  • Previous bariatric surgery
  • Bipolar disorder or psychosis
  • Steroid hormone therapy not stable for 3 months
  • Systolic blood pressure > 160 mmHg, diastolic blood pressure > 100 mmHg
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00563368

United States, North Carolina
Research Site
Durham, North Carolina, United States
United States, Pennsylvania
Research Site
Philadelphia, Pennsylvania, United States
Sponsors and Collaborators
Medpace, Inc.
Study Director: Craig Peterson VIVUS, Inc.
Study Chair: Kishore Gadde, MD Duke University
  More Information

Responsible Party: VIVUS, Inc. Identifier: NCT00563368     History of Changes
Other Study ID Numbers: OB-301
Study First Received: November 21, 2007
Results First Received: July 31, 2012
Last Updated: March 10, 2015

Additional relevant MeSH terms:
Nutrition Disorders
Body Weight
Signs and Symptoms
Neuroprotective Agents
Protective Agents
Physiological Effects of Drugs
Anti-Obesity Agents
Central Nervous System Stimulants
Appetite Depressants
Autonomic Agents
Peripheral Nervous System Agents
Adrenergic Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action processed this record on May 25, 2017