FDA Grants Orphan Drug Status to Palatin's PL7737 for Obesity from Leptin Receptor Deficiency

Palatin Technologies, Inc., a biopharmaceutical company specializing in developing innovative medicines that target the melanocortin receptor system, has recently announced that the U.S. Food and Drug Administration (FDA) has granted orphan drug designation to its oral treatment, PL7737. This drug is designed to activate the melanocortin-4 receptor (MC4R) and is aimed at treating leptin receptor (LEPR) deficiency, a rare genetic disorder often associated with obesity.

Carl Spana, Ph.D., President and CEO of Palatin, emphasized the significance of this FDA designation, highlighting it as a crucial step in advancing the development of Palatin’s MC4R receptor agonists for treating rare obesity-related conditions. Currently, the approved treatment for obesity due to leptin receptor deficiency is limited to a daily injection. PL7737, in its oral form, could potentially offer a more convenient and effective alternative for patients suffering from this genetic disorder, as well as others with similar rare obesity conditions. Additionally, Palatin is investigating the potential of PL7737 in the treatment of hypothalamic obesity and is planning to initiate a Phase 1 study focusing on single and multiple ascending doses (SAD/MAD) by the end of 2025.

Dr. Spana also noted the completion of statistical analyses for two Phase 2 clinical studies. One study investigates the combination of MC4R agonist bremelanotide with the GLP-1/GIP agonist tirzepatide for obesity treatment, while the other examines the oral formulation of PL8177 for addressing ulcerative colitis. The company anticipates releasing the topline results for these studies shortly.

LEPR deficiency is characterized by mutations in the LEPR gene that disrupt MC4R signaling within the body. The Leptin-Melanocortin pathway, located in the hypothalamus, is integral to regulating hunger, energy storage, and body weight. Individuals with this deficiency experience insatiable hunger beginning in childhood, leading to severe early-onset obesity. The role of PL7737, an MC4R agonist, is to restore the impaired signaling caused by these mutations.

The FDA’s commitment to encouraging the development of treatments for rare diseases is underscored by its authority to grant orphan drug designations. This designation provides significant incentives to sponsors, including tax credits for qualified clinical trials, exemption from user fees, and the potential for seven years of market exclusivity post-approval. It is important to note that gaining orphan drug designation is separate from the process of seeking approval or licensing of a drug. All drugs, including those for rare diseases, undergo the same rigorous scientific review process necessary for approval.

The MC4R plays a pivotal role in regulating energy balance, food intake, and body weight. Genetic mutations that interfere with MC4R signaling can lead to conditions such as hyperphagia, decreased energy expenditure, and early-onset obesity. Targeting MC4R agonism is therefore seen as a promising approach for developing obesity treatments.

Palatin Technologies focuses on creating first-in-class medicines that modulate the melanocortin receptor systems. Their strategy includes developing product candidates aimed at addressing diseases with unmet medical needs and commercial potential, followed by forming marketing partnerships with leading industry players to maximize these products' commercial success.