Image Credit: © Egor – stock.adobe.com
Palatin has announced positive results from its BMT-801 Phase II clinical trial of co-administered melanocortin-4 receptor (MC4R) agonist bremelanotide plus glucagon like peptide-1/gastric inhibitory polypeptide (GLP-1/GIP) tirzepatide for the treatment of obesity. The study met its primary endpoint, with the combination therapy demonstrating a 4.4% reduction in weight among participants.1
In a press release, Carl Spana, PhD, president & chief executive officer of Palatin said: “Although the study was not designed to optimize weight loss, this 8-week study utilizing low doses of both bremelanotide and tirzepatide, met the primary endpoint and was highly statistically significant. The positive results of this signal-generating study exceeded expectations. The data demonstrated that co-administration was additive and synergistic, resulting in increased weight loss, and that co-administration did not result in increased tolerability or safety issues for patients. The data also showed that low dose MC4R agonist bremelanotide stopped the rapid weight regain seen after ending GLP-1/GIP tirzepatide treatment.”
The 4.4% reduction in weight among patients in the co-administered arm was deemed statistically significant compared to 1.6% of patients who received the placebo. Additional findings from the study include:
- 40% of patients in the co-administered group achieved a 5% reduction in their body weight, compared to 27% for the tirzepatide alone group
- 27% of patients in the co-administered group achieved a 6% reduction in their body weight, compared to 13% for the tirzepatide alone group
- 19% of patients in the co-administered group achieved a 7% reduction in their body weight, compared to 0% for the tirzepatide alone group
- Increase in the percent of subjects on co-administration achieving 5%, 6%, and 7% weight loss over tirzepatide alone, indicates that co-administration had a synergistic effect
“This study provides compelling evidence that combining an MC4R agonist with a GLP-1/GIP compound creates a synergistic effect on weight loss. These findings align with what we observe in our clinic, where we treat patients with severe genetic obesity using both mechanisms. With a critical need for diverse weight loss solutions, this approach offers a promising improvement to GLP-1/GIP monotherapy, particularly for those who struggle with tolerability at high doses,” Jesse Richards, DO, of Oklahoma State University College of Osteopathic Medicine, said in the press release.
In the BMT-801 trial, patients first received a four-week treatment with tirzepatide alone to confirm eligibility. They were then randomized to receive co-administration of MC4R bremelanotide and GLP-1/GIP tirzepatide, tirzepatide alone, bremelanotide alone, or a placebo for an additional four weeks. The study enrolled 113 patients with 46 assigned to the MC4R plus GLP-1/GIP co-administration group.
On Feb. 6, Palatin announced the completion of the BMT-801 study. In a press release from the time, Spana said: “The MC4R pathway plays a key role in eating behavior and how our bodies manage energy. As a result, we believe that MC4R agonists, especially the highly selective MC4R long-acting peptides and oral small molecule agonists we are developing, will play an important role for treating obesity as monotherapy and/or combination therapy.”2
References
1. Palatin Announces MC4R Agonist Bremelanotide Co-Administered with GLP-1/GIP Tirzepatide Meets Primary Endpoint in Phase 2 Obesity Study. News release. Palatin. March 31, 2025. Accessed April 2, 2025. https://palatin.com/press_releases/palatin-announces-mc4r-agonist-bremelanotide-co-administered-with-glp-1-gip-tirzepatide-meets-primary-endpoint-in-phase-2-obesity-study/
2. Palatin Completes Phase 2 Obesity Study With MC4R Bremelanotide Plus GLP-1/GIP Tirzepatide. News release. Palatin. February 6, 2025. Accessed April 2, 2025. https://palatin.com/press_releases/palatin-completes-phase-2-obesity-study-with-mc4r-bremelanotide-plus-glp-1-gip-tirzepatide/