Cited by 149Pharmacology and Obesity TreatmentDiabetes Treatment and ManagementDiabetes, Cardiovascular Risks, and Lipoproteins

Weight-loss therapy in type 2 diabetes: effects of phentermine and topiramate extended release

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Garvey, W. Timothy, Ryan, Donna H., Bohannon, Nancy J.V., Kushner, Robert F., Rueger, Miriam, Dvorak, Roman V., Troupin, Barbara·2014·Diabetes Care

Abstract

OBJECTIVE: Treatment algorithms for type 2 diabetes recommend weight loss for disease management. The safety and efficacy of treatment with phentermine (PHEN)/topiramate (TPM) extended release (ER) plus lifestyle modification for weight loss and glycemic benefits were assessed in two randomized, double-blind, placebo-controlled 56-week studies of obese/overweight adults with type 2 diabetes. RESEARCH DESIGN AND METHODS: The OB-202/DM-230 Study was a 56-week phase 2 trial that randomized subjects to receive once-daily placebo or PHEN/TPM ER 15 mg/92 mg (15/92). The primary end point was change in HbA1c level. A post hoc analysis of a subpopulation with type 2 diabetes from a second study, CONQUER, is also presented. All subjects made lifestyle modifications, and comorbidities were managed to the standard of care. RESULTS: The study groups comprised 130 subjects with type 2 diabetes enrolled in the OB-202/DM-230 Study (mean baseline HbA1c 8.7% [72 mmol/mol]) and 388 subjects with type 2 diabetes in the CONQUER Study (mean baseline HbA1c 6.8% [51 mmol/mol]). At week 56 in the OB-202/DM-230, change in weight (from intent-to-treat sample with last observation carried forward [ITT-LOCF]) was −2.7% for placebo and −9.4% for PHEN/TPM ER 15/92 (P < 0.0001 vs. placebo). Change in HbA1c level (from ITT-LOCF) was −1.2% (−13.1 mmol/mol) for placebo and −1.6% (−17.5 mmol/mol) for PHEN/TPM ER 15/92 (P = 0.0381). In both the OB-202/DM-230 and CONQUER, greater numbers of patients randomized to receive PHEN/TPM ER treatment achieved HbA1c targets with reduced need for diabetic medications when compared with the placebo group. Common adverse events included paraesthesia, constipation, and insomnia. CONCLUSIONS: PHEN/TPM ER plus lifestyle modification can effectively promote weight loss and improve glycemic control as a treatment approach in obese/overweight patients with type 2 diabetes.

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  • All FDA-approved medications for chronic weight management have been shown to be effective and safe in people with type 2 diabetes in randomized controlled trials and a meta-analysis.

    “All FDAdapproved medications for chronic weight management have also been demonstrated to be effective and safe in both RCTs and a meta-analysis involving persons with T2D.735–742”

    From American Association of Clinical Endocrinology Clinical Practice Guideline: Developing a Diabetes Mellitus Comprehensive Care Plan-2022 Update. (2022) · cites this paper as [736]

    The Abstract reports two randomized, placebo-controlled studies of phentermine/topiramate extended release in adults with type 2 diabetes, and the Conclusions say it was generally well tolerated. This supports the sentence for that medication, but the paper does not establish that all FDA-approved chronic weight-management medications are effective and safe in this population, nor does it present a meta-analysis of them. The Conclusions also note a risk of hypoglycemia and a need for longer-term safety data; page numbers were unavailable in our copy. (LLM, conf=0.88)

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  • In studies of weight-loss medications in type 2 diabetes, medication arms consistently produced greater weight loss than lifestyle alone, lower A1C despite less need for diabetes medications, reductions in blood pressure, lower triglycerides and higher HDL-C, decreased hepatic transaminases, and improvements in inflammatory and other biomarkers such as CRP, fibrinogen, and adiponectin, compared to

    “The study’s weight-loss medication arms consistently resulted in: (1) greater weight loss than lifestyle alone, (2) lower A1C values despite less need for DM medications, (3) reductions in BP, (4) lower triglycerides and higher HDL-C, (5) decreased levels of hepatic transaminases, and (6) improvements in inflammatory and other biomarkers such as CRP, fibrinogen, and adiponectin, when compared to”

    From American Association of Clinical Endocrinology Clinical Practice Guideline: Developing a Diabetes Mellitus Comprehensive Care Plan-2022 Update. (2022) · cites this paper as [736]

    The OB-202/DM-230 results and Conclusions (page unavailable) report greater weight loss and improved HbA1c with phentermine/topiramate plus lifestyle modification, alongside less need for glucose-lowering medication. The Effects on Cardiometabolic Parameters section reports lower blood pressure and triglycerides and higher HDL cholesterol. Our copy does not report decreases in hepatic transaminases or improvements in CRP, fibrinogen, or adiponectin, so those parts of the attributed claim are unsupported. (LLM, conf=0.88)

    Experimental — accuracy not yet measured
  • Phentermine/topiramate 15/92 mg reduces HbA1c and weight in type 2 diabetes.

    “In a pooled subgroup analysis including T2D subjects of the CONQUER and the OB-202/DM-230 Study, the 15/92 mg dose reduced HbA1c by 0.4% (placebo subtracted) and led to up to 9.4% Weight loss over 56 weeks [36].”

    From Precision obesity medicine: A phenotype-guided framework for pharmacologic therapy across the lifespan (2025) · cites this paper as [36]

    The Abstract (page not provided) reports that, at 56 weeks in OB-202/DM-230, the 15/92 mg group lost 9.4% of body weight and had an HbA1c reduction 0.4 percentage points greater than placebo. The Methods and Results describe a separate analysis of the CONQUER type 2 diabetes subgroup, not a pooled subgroup analysis across the two studies; the quoted figures are from OB-202/DM-230. (LLM, conf=0.88)

    Experimental — accuracy not yet measured
  • Adding weight-loss medications produces significantly more weight loss than lifestyle intervention alone and yields greater A1C lowering and improvements in cardiometabolic risk factors.

    “The addition of weight-loss medications has been shown to achieve significantly more weight loss than lifestyle interventions alone and produce greater A1C lowering and improvements in cardiometabolic risk factors.”
  • Orlistat has been shown to be effective in people with type 2 diabetes.

    “and has been shown to be effective in those with T2D.735–737,739”

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Authors
Garvey, W. T., Ryan, D. H., Bohannon, N. J. V., Kushner, R. F., Rueger, M., Dvorak, R. V., & Troupin, B.
Affiliations
  • University of Alabama at Birmingham (US)
  • Pennington Biomedical Research Center (US)
  • Monteagle Medical Center, San Francisco, CA
  • Northwestern University (US)
  • Vivus (United States) (US)
Corresponding author
Garvey, W. Timothy
Venue
Diabetes Care
Published
2014-11-08
Volume
37
Issue
12
Pages
3309-3316
ISSN
  • 0149-5992 (ISSN-L)
  • 1935-5548
OpenAlex
W2157689819
Cited by
149
References
34
Citations by year
2026: 7 · 2025: 11 · 2024: 15 · 2023: 15 · 2022: 16 · 2021: 9 · 2020: 7 · 2019: 13 · 2018: 17 · 2017: 11 · 2016: 14 · 2015: 12 · 2014: 2
FWCI
9.45
Type
journal article
Language
en
Open access
Locations
  • Diabetes Care (publishedVersion)
  • PubMed (publishedVersion)
Topics
  • Health Sciences › Medicine › Pharmacology › Pharmacology and Obesity Treatment
  • Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Diabetes Treatment and Management
  • Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Diabetes, Cardiovascular Risks, and Lipoproteins
Keywords
type 2 diabetes, weight loss, glycemic control, HbA1c, obesity, lifestyle modification, combination therapy, adverse events, paresthesia, insomnia, constipation
MeSH terms
Topiramate, Adult, Blood Glucose, Delayed-Action Preparations, Diabetes Mellitus, Type 2, Double-Blind Method, Female, Fructose, Humans, Life Style, Male, Middle Aged, Obesity, Phentermine, Weight Loss, Treatment Outcome, Anti-Obesity Agents

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