Published data demonstrates the effects of PL8331 in mouse models of retinal disease

Palatin Technologies, Inc. announced manuscript publication that summarizes data demonstrating the effects of PL8331 in two mouse models of retinal disease, experimental autoimmune uveoretinitis and diabetic retinopathy. (Image Credit: Adobe Stock/Robert Kneschke)

Palatin Technologies, Inc. announced that The International Journal of Molecular Sciences published a manuscript, "Stimulating the Melanocortin System in Uveitis and Diabetes Preserves the Structure and Anti-Inflammatory Activity of the Retina". The manuscript summarizes data demonstrating the effects of PL8331 in two mouse models of retinal disease, experimental autoimmune uveoretinitis (EAU) and diabetic retinopathy (DR). Palatin and the National Institute of Health (NIH) and the Massachusetts Lions Eye Research Foundation provided funding for the study.

"We have long studied the endogenous mechanisms of anti-inflammatory activity within the healthy eye, in which the melanocortin system is key," stated Andrew W. Taylor, Ph.D., Associate Dean of Research at Boston University. "Our results show that engaging the melanocortin system in eye pathology is more than suppressing inflammation. It promotes cell survival and preserves normal anti-inflammatory activity within the eye."

Both models evaluated the efficacy of PL8331 as an agonist at the melanocortin 1 (MC1r) and melanocortin 5 (MC5r) receptors.

In the EAU mouse model, PL8331 treatment resulted in resolution of inflammation and preservation of retinal structure. Specifically, PL8331 protected the retinal photoreceptors from the auto-inflammatory damage that normally occurs in the EAU model.

In the DR mouse model, PL8331 treatment resulted in enhanced survival of various types of retinal cells and the suppression of vascular endothelial growth factor (VEGF). VEGF plays a major role in the pathology of DR. In addition, the retinal pigmented epithelial cells (RPE) were able to maintain their normal anti-inflammatory activity.

"This manuscript summarizes quite nicely the great potential of utilizing melanocortin agonists to treat inflammatory conditions in the back of the eye, specifically the retina," said Carl Spana, Ph.D., President and CEO of Palatin. "This data adds to Palatin's extensive pre-clinical data with melanocortin agonist in retinal disease models and supports future clinical development."

The findings from both studies clearly demonstrate the importance of the melanocortin system in protecting the eye from the damage caused by pathological inflammation and support the potential of melanocortin agonists as treatments for various retinal diseases.

About Melanocortin Receptor Agonists and Inflammation

The melanocortin receptor ("MCr") system has effects on inflammation, immune system responses, metabolism, food intake, and sexual function. There are five melanocortin receptors, MC1r through MC5r. Modulation of these receptors, through use of receptor-specific agonists, which activate receptor function, or receptor-specific antagonists, which block receptor function, can have medically significant pharmacological effects. Many tissues and immune cells located throughout the body, including the gut, kidney, and eye, express melanocortin receptors, empowering our opportunity to directly activate natural pathways to resolve disease inflammation.