Response Pharmaceuticals has announced the early completion of enrollment for their Phase 2 clinical trial evaluating RDX-002, marking a significant step forward in addressing post-GLP-1 weight management challenges. The study, which finished enrollment 12 months ahead of schedule, aims to assess the drug's effectiveness in preventing weight rebound in patients discontinuing GLP-1 agonists such as semaglutide and tirzepatide.
Addressing a Critical Unmet Need
"GLP-1 agonists have been transformative for patients struggling with obesity," explains Eric Keller, Response Pharmaceuticals' CEO. "However, recent data from several studies (STEP-1, STEP-4, SURMOUNT-4) suggest that following discontinuation of the GLP-1 drugs semaglutide and tirzepatide, most patients rapidly regain much of the weight lost; and with the weight regain, the risk of developing obesity-related comorbidities, such as high blood pressure, cardiovascular disease and Type 2 diabetes, returns."
Trial Design and Objectives
The double-blind study (NCT06640972) will evaluate RDX-002's efficacy and tolerability over a 12-week period. The trial focuses on patients who have achieved significant weight loss using GLP-1 agonist drugs but are planning to discontinue treatment. As a first-in-class inhibitor of intestinal microsomal triglyceride transfer protein (iMTP), RDX-002 works by decreasing the amount of triglycerides and cholesterol delivered to the body after meals.
Promising Development History
Dr. Bill Sasiela, Chief Medical Officer at Response Pharmaceuticals, highlighted the drug's potential based on previous studies: "RDX-002 has shown promise in a separate, recently completed Phase 1 study focusing on another drug-induced weight management setting, anti-psychotic induced weight gain (AIWG)."
The drug candidate has been evaluated in multiple clinical trials involving over 400 subjects, with dosing periods up to 84 days. These studies have demonstrated RDX-002's ability to lower post-prandial triglyceride levels, reduce circulating levels of low-density lipoprotein cholesterol (LDL-C), and decrease weight. Safety data has been encouraging, with adverse events primarily limited to mild to moderate gastrointestinal effects and no serious adverse events attributed to the drug.
Looking Forward
The rapid enrollment completion reflects the growing concern over post-GLP-1 weight rebound, particularly given the widespread adoption of these weight loss medications. Response Pharmaceuticals expects to report trial data by the end of the second quarter of 2025, while simultaneously preparing for a Phase 2b study in their lead indication, antipsychotic-induced weight gain.
The development of RDX-002, which is being advanced under an exclusive worldwide license from Sanofi S.A., represents a potential breakthrough in managing weight regain following GLP-1 agonist discontinuation, addressing a significant gap in current treatment options.
