RDX-002 Achieves Primary Endpoint in Trial for Post-GLP-1 Weight Management

Response Pharmaceuticals has announced positive topline results from their phase 2 study testing their investigative therapy RDX-002 in maintaining weight loss and metabolic benefits in patients with obesity who had completed a GLP-1 RA course.

RDX-002, an investigational first-in-class small molecule inhibitor, targets intestinal microsomal triglyceride transfer protein to reduce post-meal uptake of triglycerides, calories, and cholesterol. Response Pharmaceuticals is currently developing it as a therapy for drug-induced weight gain, particularly in patients taking anti-psychotic medications and those discontinuing GLP-1 RAs.1

GLP-1 RAs have gained a significant amount of public attention in the last few years, with major benefits in type 2 diabetes, as well as various cardiovascular and renal benefits. However, existing analyses have indicated a surprisingly high number of patients who discontinue treatment after 1 year. This leads to a gradual regaining of weight, returning patients relatively quickly to the same cardiovascular risk as when they began treatment.2

“GLP-1 Receptor Agonist therapies have revolutionized obesity treatment, but they are not the end of the story,” said Chris Packard, professor and honorary senior research fellow at the School of Cardiovascular and Metabolic Health, University of Glasgow. “Many people regain weight and experience the return of an adverse cardiometabolic profile after stopping GLP-1 RA therapy. A novel treatment that can sustain and build upon the gains achieved with GLP-1 receptor agonists presents a potentially important advance in long-term obesity care.”1

During the trial, RDX-002 demonstrated statistically significant reductions in blood fat levels after eating and reduction in weight regain versus placebo over 12 weeks. It exhibited a mean reduction of -227.3 mg x hr/dL in postprandial triglycerides at week 12 versus placebo change of 64.1 mg x hr/mL (LS mean difference, -93.5; P <.001). Additionally, patients receiving RDX-002 gained less weight (-2.94%, -34% relative difference) versus placebo (P = .019).1

Additionally, RDX-002 resulted in improved measures of cardiometabolic health, such as blood pressure and high-sensitivity C-reactive protein while maintaining a favorable safety and tolerability profile. Efficacy was sustained over 12 weeks, which will be further confirmed during an ongoing open-label extension of 24 weeks.1

Of note is the fact that RDX-002 achieved its primary endpoint of statistically significant reduction in blood fat levels after eating (-51.9%), as well as secondary endpoints of statistically significant weight regain reduction and improvement in cardiometabolic risk factors compared to placebo.1

“These results confirm our data from prior studies and highlight RDX-002’s potential to address what is recognized increasingly as a critical gap in obesity management following GLP-1 RA therapy,” said William Sasiela, PhD, chief medical officer of Response Pharmaceuticals. “We believe this mechanism of action offers a differentiated and complementary approach to help patients maintain and over the long term enhance the health benefits they receive with GLP-1s, and we look forward to confirming the durability of these effects in the ongoing open-label extension study.”1

References

1. Response Pharmaceuticals, Inc. Response Pharmaceuticals Announces Positive Top-Line Results From Phase 2 Study of RDX-002 in Post-GLP-1 Management. BusinessWire. August 13, 2025. Accessed August 13, 2025. https://www.businesswire.com/news/home/20250813869741/en/Response-Pharmaceuticals-Announces-Positive-Top-Line-Results-From-Phase-2-Study-of-RDX-002-in-Post-GLP-1-Management

2. Yao H, Zhang A, Li D, et al. Comparative effectiveness of GLP-1 receptor agonists on glycaemic control, body weight, and lipid profile for type 2 diabetes: systematic review and network meta-analysis. BMJ. 2024;384:e076410. Published 2024 Jan 29. doi:10.1136/bmj-2023-076410