Response Pharmaceuticals' Ex-Sanofi Asset Shows Promise in Post-GLP-1 Weight Management

Response Pharmaceuticals has unveiled promising phase 2 data for its investigational drug RDX-002, demonstrating potential benefits for patients who have discontinued GLP-1 receptor agonist treatments for obesity. The oral iMTP inhibitor, originally licensed from Sanofi, has shown efficacy in reducing blood-fat levels and mitigating weight gain in individuals who previously used popular obesity medications like Eli Lilly's Zepbound and Novo Nordisk's Wegovy.

Phase 2 Trial Results

The 12-week randomized trial involved 68 participants who had lost at least 10% of their body weight or 10 kg while taking Zepbound or Wegovy before discontinuing treatment. RDX-002 achieved its primary endpoint, demonstrating a statistically significant reduction in postprandial blood-fat levels compared to placebo. Additionally, the drug met a key secondary endpoint related to weight gain prevention following GLP-1 discontinuation.

Safety data from the trial were encouraging, with no serious adverse events reported and no patients discontinuing treatment due to side effects. Mild to moderate gastrointestinal adverse events were observed but generally resolved early in the treatment course.

Mechanism of Action and Market Potential

RDX-002 targets a protein involved in triglyceride transfer, a mechanism that has been explored by other pharmaceutical companies, including Bristol Myers Squibb. The FDA previously approved Aegerion Pharmaceuticals' Juxtapid, another MTP inhibitor, as a lipid-lowering drug in 2012.

Dr. William Sasiela, Chief Medical Officer at Response Pharmaceuticals, highlighted the potential of RDX-002, stating that the mechanism may offer a "differentiated and complementary approach to help patients maintain and, over the long term, enhance the health benefits they achieve with GLP-1s." The company is exploring opportunities to test the drug candidate in combination with GLP-1 receptor agonists, addressing a growing need in the obesity treatment landscape.

Addressing Post-GLP-1 Treatment Challenges

The development of RDX-002 addresses a significant challenge in obesity management. While GLP-1 receptor agonists like Zepbound and Wegovy have shown remarkable efficacy in promoting weight loss, studies indicate that many patients discontinue these medications and subsequently regain lost weight. Response Pharmaceuticals initially targeted antipsychotic-induced weight gain but has pivoted to focus on the post-GLP-1 market, recognizing the need for interventions that can help patients maintain their weight loss after stopping GLP-1 therapy.

As the obesity treatment market continues to evolve, RDX-002 represents a potential solution for maintaining the long-term benefits of GLP-1 receptor agonist therapy. Response Pharmaceuticals plans to present full data from the phase 2 study at an upcoming medical meeting, which will likely provide further insights into the drug's efficacy and safety profile.