OKYO Pharma enrols first patients in Phase 3 urcosimod NCP trial

OKYO Pharma has enrolled the first patients in NEPTUNE, its Phase 3 registrational trial evaluating urcosimod in adults with neuropathic corneal pain (NCP). The study opened at Toyos Clinic in Nashville, Tennessee, under the direction of Melissa Toyos, MD, with additional sites planned across the United States and in Italy, Spain, and France.

Urcosimod is a lipid-conjugated chemerin peptide agonist that targets the ChemR23 G-protein-coupled receptor, found on ocular immune cells as well as on neurons and glial cells in the dorsal root ganglion. The company says this dual mechanism is designed to address both the inflammatory and neurological components of NCP, positioning the candidate as a potential first disease-modifying therapy in the indication.

"Neuropathic corneal pain is one of the most debilitating conditions I see in my practice, and right now we have no FDA approved therapy to offer these patients, many of whom have tried everything and are still suffering," said Toyos, commenting on why enrolment is consequential for patients.

Trial design

NEPTUNE, an acronym for Neuropathic Eye Pain Treatment with Urcosimod and Nerve Evaluation, will treat participants with four drops per day over 12 weeks. The primary endpoint is change from baseline in ocular pain as measured by a visual analogue scale (VAS) score. Secondary endpoints include quality-of-life assessments and in-vivo confocal microscopy findings, which can capture structural changes to corneal nerve fibres and are increasingly used by regulators as an objective correlate in NCP studies. The trial is designed in accordance with FDA guidance as a registrational study; OKYO has not disclosed the target enrolment size or a projected completion date.

Flavio Mantelli, OKYO's chief medical officer, described the site activation as "an important milestone for building the clinical evidence necessary to support the potential first disease modifying treatment" for the condition.

Market and competitive context

NCP remains an area of genuine unmet need. The condition is thought to arise from damage or dysfunction of corneal sensory nerves, often compounded by chronic inflammation, and its symptoms can include severe ocular pain disproportionate to any observable physical signs. No therapy has received FDA or EMA approval specifically for NCP, meaning patients are typically managed with off-label analgesics, topical anti-inflammatory agents, or autologous serum eye drops, none of which addresses the underlying neurological mechanism.

The ophthalmic pain space has attracted interest from several smaller biotechs and academic groups pursuing neuromodulatory and regenerative approaches, though none has yet generated Phase 3 data. OKYO's decision to pursue a multicenter, multinational registrational study rather than a smaller proof-of-concept design signals confidence in its preclinical and Phase 2 pharmacology package, even as the company has not published full Phase 2 data in peer-reviewed form.

For investors, the key near-term milestones will be the pace of site activation across European centres, interim safety signals, and whether OKYO pursues a regulatory designation such as FDA Breakthrough Therapy or Fast Track status that could accelerate the timeline to a potential new drug application. OKYO trades on the Nasdaq Capital Market under the ticker OKYO.