Palatin Announces Positive Results from PL9643 Study in Patients with Dry Eye Disease

Palatin Technologies announced positive results in its Phase 2 study of PL9643 for the treatment of dry eye disease (DED). Statistically significant improvement in multiple signs and symptoms was achieved in the moderate to severe patient population after 2 weeks of dosing and at the 12-week visit. There were no safety signals identified and PL9643 had excellent ocular tolerability. However, statistical significance for the primary endpoints was not reached in the overall enrolled population that included mild, moderate, and severe patients, as measured at the 12-week primary evaluation visit.

"This was our first study evaluating a melanocortin agonist in an ocular disease and we are pleased that the key goals of this study were met, which was providing significant clinical evidence of efficacy, safety, and tolerability in a meaningful patient population - patients suffering from moderate to severe DED," said Carl Spana, Ph.D., President and CEO of Palatin. "Importantly, we have a clear development and regulatory path forward. With approximately 20 million adults in the United States currently suffering from DED, the majority being moderate to severe patients, and up to 50% discontinuing treatment due to slow onset, lack of efficacy or intolerance, PL9643's potentially quick onset of efficacy and excellent tolerability profile are differentiating factors to current approved therapies."

In the sub-population of moderate to severe patients (N=61), PL9643 achieved statistical significance (P value <0.05 vs. vehicle) at week 2 and week 12 for multiple signs, including inferior (the primary sign endpoint), superior, and total corneal staining, temporal, nasal and total conjunctival staining, tear film break-up time, and multiple ocular symptoms, including ocular discomfort. Additionally, multiple sign and symptom measures trended towards significance (P value <0.1 vs. vehicle). Based on these positive trial results, Palatin plans to initiate a Phase 2/3 trial in the United States in mid calendar year 2021.

"This work, utilizing the melanocortin pathway, is an excitingly novel departure from all other dry eye therapeutic strategies," said Kenneth Kenyon, M.D., Principal Investigator for the study, cornea specialist at New England Eye Center and Professor of Ophthalmology, Tufts University School of Medicine. "The demonstrated consistency of improved outcomes across multiple sign and symptom time points is most impressive. Significant improvement in both corneal and conjunctival staining is highly relevant, as it affects both vision and irritative symptoms, especially so in these more advanced dry eye patients. The emerging profile of PL9643, with its rapid therapeutic onset and excellent tolerability profile, is a potentially distinct advance in dry eye therapy."

"The Phase 2 study of PL9643 has provided guidance on the clinical and regulatory pathway forward for this program. The results identify the most appropriate patient population, endpoints, and timepoints for the next study. We look forward to working with Palatin to confirm the therapeutic potential of PL9643 in treating the signs and symptoms of dry eye" said George Ousler, Senior Vice President, Anterior Segment at Ora, Inc.

This Phase 2 study was a multi-center, randomized, double-masked and vehicle-controlled study evaluating the efficacy and safety of PL9643 ophthalmic solution (topical eye drops) compared to vehicle for the treatment of the signs and symptoms of dry eye. The study enrolled 160 participants randomized in a 1:1 ratio into two arms, PL9643 or vehicle, at four sites in the United States. Patients underwent 12 weeks of daily treatment. The intent to treat (ITT) population included all patients with mild-moderate-severe DED. The two prespecified primary endpoints were improvement in inferior corneal staining (sign) and ocular discomfort (symptom) as measured at the 12-week primary evaluation visit. There were multiple secondary sign and symptom outcome measures as well.

Trial results demonstrated an excellent safety and tolerability profile. There were no serious adverse events associated with study treatment observed. Three patients on placebo and one patient on PL9643 (not deemed to be drug related) discontinued from the study. Importantly, there were no ocular, drug-related adverse events in the PL9643 subjects.