Kiora Pharmaceuticals' KIO-104 Shows Promise in Treating Proliferative Vitreoretinopathy with Complete Scar Prevention in Preclinical Study

Kiora Pharmaceuticals presented preclinical data at ARVO 2025 demonstrating KIO-104's potential to treat proliferative vitreoretinopathy (PVR), a condition with no FDA-approved treatments. High-dose KIO-104 completely prevented scar formation, and low-dose KIO-104 reduced scar formation in a rabbit model. The data supports KIO-104's future development for treating PVR, which is characterized by unchecked cellular proliferation and fibrosis leading to retinal detachment and vision loss. KIO-104 is already in Phase 2 clinical trials for other retinal diseases.

Kiora Pharmaceuticals (NASDAQ: KPRX) recently presented preclinical data for KIO-104 at the 2025 Association for Research in Vision and Ophthalmology (ARVO) meeting, showcasing the compound's potential to treat proliferative vitreoretinopathy (PVR). PVR is a severe complication following retinal detachment surgery, characterized by uncontrolled cellular proliferation and fibrosis, leading to retinal detachment and vision loss. Currently, there are no FDA-approved treatments for PVR.

The study, presented by Romana Seda-Zehetner, MSc MScTox, Kiora's Director of Preclinical Development, demonstrated significant reduction in scar formation using KIO-104 in a rabbit model. The high-dose group (10 μg/eye) completely prevented scar formation in all subjects, while the low-dose group (1 μg/eye) showed reduced scar formation with only 9 retinal scars in 2 of 6 rabbits, compared to the control group which developed 20 retinal scars in 4 of 6 animals. The mean scar length in the high-dose group was 43 ± 16 μm, significantly lower than the 110 ± 28 μm in the control group [1].

The data supports the further development of KIO-104 for treating PVR, which has a substantial unmet medical need. KIO-104, a small molecule DHODH inhibitor, targets an essential molecular pathway for rapidly dividing cells, de novo biosynthesis of pyrimidine nucleotides, thereby reducing scar formation and inflammation. The complete prevention of scar formation in the high-dose group is particularly noteworthy, as it addresses a critical endpoint for this condition.

However, investors should recognize that this represents very early-stage research. The translational gap between animal models and human efficacy is substantial, and preclinical success does not guarantee clinical results. No timeline was provided for potential clinical development in PVR, suggesting commercial applications remain distant. The dose-dependent response (complete prevention at high dose, partial at low dose) strengthens confidence in the mechanism, though safety data was not addressed.

For a small biotech company, expanding indications for lead compounds is strategically sound, potentially maximizing return on R&D investment if successful. KIO-104's complete prevention of scarring in the PVR model addresses a significant unmet need, but human trials remain distant. Proliferative vitreoretinopathy represents a serious complication following retinal detachment surgeries, occurring in approximately 5-10% of cases. The condition develops when inflammatory processes trigger uncontrolled cellular proliferation, creating fibrous membranes that contract and re-detach the retina. Each subsequent surgery carries diminishing success rates, making PVR a dreaded complication among retinal specialists.

Kiora Pharmaceuticals is a clinical-stage biotechnology company developing advanced therapies for retinal disease. KIO-104 is being evaluated in a Phase 2 clinical trial in patients with macular edema, an inflammation-driven condition secondary to several conditions including diabetic retinopathy and posterior non-infectious uveitis. KIO-301 is being developed for the treatment of retinitis pigmentosa, choroideremia, and Stargardt disease. It is a molecular photoswitch that has the potential to restore vision in patients with inherited and/or age-related retinal degeneration.

The company's preclinical PVR data shows promise, but represents early-stage research with significant development hurdles ahead. The complete prevention of scar formation in the high-dose group is particularly noteworthy, as it addresses a critical endpoint for this condition. However, the transition from subretinal injection in controlled experimental settings to clinical application faces multiple challenges.

References:
[1] https://www.stocktitan.net/news/KPRX/kiora-pharmaceuticals-presents-in-vivo-preclinical-data-at-arvo-2025-pjv8psi6ztm7.html