Long-term Effectiveness of the Antiobesity Medication Phentermine

Summary

The purpose of this research study is to understand the long-term effects of the drug phentermine on weight, blood pressure, other health outcomes, and safety. Phentermine has been approved by the US Food and Drug Administration (FDA) for weight management since 1959, but it has not been approved for long-term use (i.e., treatment lasting more than 12 weeks). This trial is designed to learn about the long-term effects of phentermine for up to 2 years because obesity is a chronic disease and expert guidelines recommend long-term use of anti-obesity medications as one treatment option.

Conditions

• Obesity
• Obesity; Drug
• Lifestyle, Healthy

Interventions

BEHAVIORAL

Online Lifestyle Behavioral Therapy

Participants will receive access to the WW™ digital application for the duration of their participation. The WW™ digital application can be accessed using a smartphone, tablet or personal computer and includes functions such as food journaling, progress charts, lifestyle coaching , ability to manually enter exercise data or link with a fitness tracking device, incentives for behavior change, recipes, and local restaurant recommendations using GPS. Over the course of 12 clinic visits with an obesity provider, participants will be prescribed a dietary plan based on the WW™ app and will be asked to journal dietary intake.

DRUG

Phentermine Hydrochloride 8 MG

At the randomization visit, participants will be started on 8 mg PO daily of phentermine or placebo, with a recommendation to take the medication in the morning. They will be provided with detailed instructions on how to increase their dose of study drug over the subsequent weeks. After one week, participants will increase to 16 mg daily. After the second week, participants will further increase their dose to 24 mg daily and at the 1-month in-person follow-up, participants who tolerate the 24 mg dose will be maintained on this as the maximum daily dose for a total of 24 months. For participants who do not tolerate an escalation in medication dose due to side effects, adverse events, and/or elevations in blood pressure and/or heart rate, the study clinician may adjust the dose and/or delay dose escalation. Study clinicians will work with participants to achieve and sustain the maximum dose tolerated.

Sponsors & Collaborators

• Johns Hopkins University

  collaborator OTHER

• Kaiser Permanente

  collaborator OTHER

• HealthPartners Institute

  collaborator OTHER

• The University of Texas Health Science Center, Houston

  collaborator OTHER

• Biomedical Research Institute of New Mexico

  collaborator OTHER

• WW International Inc

  collaborator INDUSTRY

• KVK-Tech, Inc.

  collaborator UNKNOWN

• National Heart, Lung, and Blood Institute (NHLBI)

  collaborator NIH

• Wake Forest University Health Sciences

  lead OTHER

Principal Investigators

• Kristina H Lewis, MD · Wake Forest University Health Sciences

• Jamy D Ard, MD · Wake Forest University Health Sciences

• Nicholas M Pajewski, PhD · Wake Forest University Health Sciences

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

QUADRUPLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

70 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2022-06-30

Primary Completion

2026-12-31

Completion

2026-12-31

FDA Drug

Yes

Countries

• United States

Study Locations