Response Pharmaceuticals Advances Its Position in Long-Term Weight Management
FALLS CHURCH, Va.--(BUSINESS WIRE)--#AIWG--Response Pharmaceuticals, Inc., a clinical-stage biopharmaceutical company developing therapies for weight management and metabolic health, reinforces its position as a differentiated long-term potential solution in obesity care with positive Phase 2 open-label extension (OLE) data for RDX-002.
“Obesity is increasingly recognized as a chronic, relapsing disease associated with significant, cumulative cardiometabolic risk and long-term morbidity and mortality,” said Professor Chris Packard, Institute of Cardiovascular and Medical Sciences, University of Glasgow. “Weight loss reduces cardiometabolic risk factors but has to be maintained to gain full benefit. There is a clear need for durable management strategies that maintain weight loss and the associated cardiometabolic treatment benefits over the long term.”
In a study examining body weight regained among patients who recently discontinued GLP-1 receptor agonists (RAs) for weight loss, RDX-002 achieved a clinically meaningful mean preservation of 57% of the weight loss seen with the GLP-1 RA at 36 Weeks.
“In a therapeutic landscape where tolerability and high discontinuation rates continue to limit long-term body weight management, these data position RDX-002 as a differentiated and potentially durable solution for chronic obesity management and care,” said Dr. William Sasiela, Chief Medical Officer of Response Pharmaceuticals. “While GLP-1 agonists are highly effective at reducing weight, 65% of patients discontinue GLP-1 agonist treatment within one year of starting according to a recent NIH cohort study of over 125,000 patients, with an average weight regain of 67% over 52 weeks. In practice, this often means that weight loss and initial cardiometabolic improvements are difficult to sustain, which poses clinical challenges for patients and healthcare providers.”
The 36-week Phase 2 study enrolled 68 participants after their planned discontinuation of GLP-1 RA treatment for weight management, and consisted of a 12-week randomized, double-blind, placebo-controlled portion followed by a 24-week open-label extension. Results demonstrated both early and sustained benefit, supporting durability of effect in the post-GLP-1 setting.
Key Study Highlights
- Met primary endpoint of reduction of postprandial triglyceride response to a standardized high fat meal (AUC: –93.5% vs. placebo (p<0.001) at Week 12)
- After stopping GLP-1 RA therapy, subjects on RDX-002 preserved 57% of prior GLP-1–associated weight loss at Week 36.
- Subjects who switched from placebo to RDX-002 for the OLE portion of the study also saw significant reductions in the rate of weight regain: 0.58% per week lowered to 0.14% per week after cross-over. This is approximately 50% of what would be expected based on prior clinical data of GLP-1 RA discontinuation.
- Over 12 weeks of RDX-002 treatment there was less total body fat mass gain versus placebo (1.99% vs 6.71%).
- Treatment improvements were seen in blood pressure and high-sensitivity C-reactive protein (hsCRP) versus placebo.
- RDX-002 was generally well-tolerated. The most common adverse events were mild/moderate diarrhea, upper respiratory tract infection, nausea, and abdominal pain.
Across the 36 weeks of the study, one patient in each of the RDX-002 and placebo treatment groups discontinued due to an adverse event. No patients treated with RDX-002 experienced a serious adverse event as compared to one patient receiving placebo. Mild/moderate, transient gastrointestinal events were the most common treatment-related adverse events. Changes in the frequency and consistency of bowel movements occurred primarily in the first two weeks following initiation of RDX-002 with minimal differences versus placebo in the subsequent treatment weeks. Other treatment-emergent adverse events, including common infections and upper respiratory illnesses, were observed in both treatment arms.
As obesity management shifts from short-term aggressive weight loss to long-term care, a critical unmet need is becoming clear: how to prevent weight regain after discontinuation of GLP-1–based therapies such as Wegovy and Zepbound. RDX-002’s gut-restricted mechanism is designed to minimize systemic exposure while maintaining metabolic benefits, enabling a safe and tolerable approach to long-term weight maintenance.
About Response Pharmaceuticals
Response Pharmaceuticals is a clinical-stage biopharmaceutical company developing therapies for weight management and metabolic health in high-need populations. The company’s lead programs focus on addressing antipsychotic-induced weight gain (AIWG) in patients with serious mental illness and supporting individuals transitioning off weight loss drugs in maintaining their weight loss and cardiometabolic benefits. Adjunctive Phase 2 studies are being explored in settings marked by significant weight gain or metabolic disruption, including potential combination use with other therapies. The company is planning to initiate a Phase 2 study evaluating RDX-002 in antipsychotic-induced weight gain, a population with elevated cardiometabolic risk and limited treatment options.
About RDX-002
RDX-002, Response Pharmaceuticals’ lead candidate, is an investigational first-in-class, potent, selective, and gut-specific small molecule inhibitor of intestinal microsomal triglyceride transfer protein (iMTP). The overall effect of iMTP inhibition is a reduction in the post-meal uptake of triglycerides (fat)—and thus calories—and cholesterol by the body. RDX-002 is being developed as a therapy to address drug-induced weight gain and decrease cardiometabolic risk, including in patients taking life-saving anti-psychotic medications and those discontinuing GLP-1 RAs for the treatment of obesity. RDX-002 has been studied in multiple Phase 1 and Phase 2 clinical trials in more than 450 healthy subjects and patients dosed up to 252 days. In these studies, RDX-002 lowered post-prandial triglyceride levels and circulating levels of low-density lipoprotein cholesterol (LDL-C), and reduced weight. RDX-002 was generally well-tolerated, with adverse events restricted to mostly mild to moderate gastrointestinal effects. No serious adverse events have been attributed to RDX-002. RDX-002 is being developed under an exclusive world-wide license from Sanofi S.A.
For more information, please visit https://www.responsepharmaceuticals.com.
Contacts
Press and Investor Contact
Sabine Bisson, PhD
Chief Operating Officer, Response Pharmaceuticals Inc.
press@responsepharmaceuticals.com
