Phentermine/Topiramate extended release versus Lorcaserin for weight reduction in obese adult patients: design of a randomized, double-blind, multicentric clinical study

Abstract

Background and Aim: Obesity is a major health concern in the world. Pharmacological strategies are accepted as part of obesity treatment, but a standard intervention is yet to be established. Phentermine/Topiramate extended release (ER) and Lorcaserin have been approved for obesity treatment and a head-to-head comparison could help outline guidelines for standardized pharmacological therapy in this area. Therefore we aim to assess whether Phentermine/Topiramate ER is superior to Lorcaserin in body weight reduction after 54 weeks of follow up.
Design: Randomized, double blind, double-dummy, multicentric clinical trial.
Participants: Adults aged from 18 to 65 years, with body mass index (BMI)=30-40kg/m2, or BMI=27-30kg/m2 with at least one comorbidity.
Measurements and procedures: Participants will be randomized using a block design with randomly selected sizes, stratified by study center, and a 1:1 ratio, to receive either Phentermine/Topiramate ER 7.5mg/46mg qd (+placebo), or Lorcaserin 10mg bid (+placebo). Baseline laboratory characteristics will be documented at screening visit, and baseline clinical characteristics of eligible individuals, up to 2 weeks later. After a 2-week titration period, participants will be monthly assessed for 52 weeks. Primary outcome: proportion of subjects with a minimum 5% weight reduction from baseline bodyweight after a 54-week follow up. Secondary outcomes: mean weight change; proportion of subjects with a minimum 10% weight reduction; quality of life; blood pressure; waist circumference; lipoprotein lipids; fasting glucose; insulin; and glycated hemoglobin levels. Investigators and participants will be blinded to treatment.
Ethical aspects: This trial will follow the Declaration of Helsinki and the ICH Harmonized Tripartite Guidelines for Good Clinical Practice, and only participants who sign informed consent form and fully understand every component of the study procedures will be eligible. A Data Monitoring Committee will be established to provide quality control and assure that study procedures are followed.
Key-Words: Obesity, Phentermine, Topiramate, Lorcaserin, Weight Loss, Obesity Treatment.