Palatin Presents Promising Preclinical Data on Melanocortin Agonists for Retinopathy at ARVO 2025

In This Article:

Findings highlight PL9654 and PL9655's potential to treat diabetic retinopathy through inflammation resolution, vascular stabilization, and neuroprotection

  • PL9654 and PL9655 down-regulate inflammatory pathways, suppress angiogenesis, and preserve retinal structure and function

  • Topical and systemic administration options enable potential for earlier intervention than current therapies

  • Results support the continued development of PL9654 and PL9655 for the treatment of diabetic retinopathy (DR)

CRANBURY, N.J., May 9, 2025 /PRNewswire/ -- Palatin Technologies, Inc. (OTC PINK: PTNT), a biopharmaceutical company advancing innovative treatments targeting the melanocortin receptor system, today announced new preclinical data on its melanocortin agonists PL9654 and PL9655 at the 2025 Association for Research in Vision and Ophthalmology (ARVO) Annual Meeting.

Palatin Technologies, Inc.
Palatin Technologies, Inc.

The findings demonstrate the agents' ability to resolve inflammation, stabilize the blood-retinal barrier, reduce VEGF signaling, and protect retinal ganglion cells, key drivers of vision loss in diabetic retinopathy. Notably, both compounds showed efficacy across multiple models and routes of administration, including topical delivery.

The poster, titled "Activating the melanocortin system resolves inflammation, reduces VEGF signaling in diabetic retinopathy (DR), and provides retinal ganglion cell (RGC) protection," was presented by Paul Kayne, Ph.D., Vice President, Biological Sciences at Palatin. The full poster is available at www.palatin.com.

"Palatin's melanocortin research data are unparalleled in demonstrating multi-pathway inflammation resolution," said Carl Spana, Ph.D., President and CEO of Palatin. "The ability to modulate immune response, suppress angiogenesis, and preserve neural integrity, especially via topical administration, could transform treatment for retinal diseases like diabetic retinopathy."

Key Findings:

  • Vision preservation: PL9654 and PL9655 maintained contrast vision and showed significant efficacy compared to vehicle.

  • Inflammation control: Gene set enrichment analysis revealed downregulation of immune-related pathways in microglia and Müller glial cells for PL9654 and PL9655 compared to vehicle.

  • Retinal protection: PL9654 reduced ischemia-reperfusion-induced retinal damage (as measured by histological scoring), similar to the melanocortin peptide α-MSH.

  • Cell integrity: Microglia and Müller glial cell levels in treated animals mirrored those in healthy controls.

  • Neuroregeneration: Topical PL9655 treatment increased rod photoreceptor levels relative to vehicle.

  • Anti-angiogenesis: PL9654 significantly inhibited choroidal neovascularization and fibrosis (P<0.01). PL9655 topical treatment also showed an increase in rods compared with vehicle.