Kiora Pharmaceuticals Presents In Vivo Preclinical Data at ARVO 2025 Demonstrating the Potential of KIO-104 to Treat Proliferative Vitreoretinopathy
Kiora Pharmaceuticals (NASDAQ: KPRX) presented promising preclinical data for KIO-104, their novel DHODH inhibitor, at ARVO 2025. The study demonstrated significant reduction in scar formation for treating proliferative vitreoretinopathy (PVR), the leading complication following retinal detachment surgery.
Key findings from the rabbit model study showed: The high dose group (10 μg/eye) completely prevented scar formation in all subjects. The low dose group (1 μg/eye) showed reduced scar formation with only 9 retinal scars in 2 of 6 rabbits, with mean scar length of 43 ± 16 μm. The control group developed 20 retinal scars in 4 of 6 animals, with mean scar length of 110 ± 28 μm.
KIO-104 is currently in Phase 2 clinical trials for macular edema treatment in patients with diabetic retinopathy and posterior non-infectious uveitis.
Kiora Pharmaceuticals (NASDAQ: KPRX) ha presentato dati preclinici promettenti per KIO-104, il loro nuovo inibitore DHODH, durante ARVO 2025. Lo studio ha evidenziato una significativa riduzione della formazione di cicatrici nel trattamento della vitreo-retinopatia proliferativa (PVR), la principale complicanza dopo un intervento di distacco della retina.
I risultati chiave dello studio sul modello con conigli hanno mostrato: Il gruppo ad alta dose (10 μg/occhio) ha completamente prevenuto la formazione di cicatrici in tutti i soggetti. Il gruppo a bassa dose (1 μg/occhio) ha mostrato una riduzione della formazione di cicatrici, con solo 9 cicatrici retiniche in 2 su 6 conigli, con una lunghezza media delle cicatrici di 43 ± 16 μm. Il gruppo di controllo ha sviluppato 20 cicatrici retiniche in 4 su 6 animali, con lunghezza media delle cicatrici di 110 ± 28 μm.
Attualmente, KIO-104 è in fase 2 di sperimentazione clinica per il trattamento dell’edema maculare in pazienti con retinopatia diabetica e uveite posteriore non infettiva.
Kiora Pharmaceuticals (NASDAQ: KPRX) presentó datos preclínicos prometedores para KIO-104, su nuevo inhibidor de DHODH, en ARVO 2025. El estudio demostró una reducción significativa en la formación de cicatrices para el tratamiento de la vitreorretinopatía proliferativa (PVR), la principal complicación tras la cirugía de desprendimiento de retina.
Los hallazgos clave del estudio en modelo de conejo mostraron: El grupo de alta dosis (10 μg/ ojo) previno completamente la formación de cicatrices en todos los sujetos. El grupo de baja dosis (1 μg/ ojo) mostró una reducción en la formación de cicatrices, con solo 9 cicatrices retinianas en 2 de 6 conejos, con una longitud media de cicatriz de 43 ± 16 μm. El grupo control desarrolló 20 cicatrices retinianas en 4 de 6 animales, con una longitud media de cicatriz de 110 ± 28 μm.
KIO-104 se encuentra actualmente en ensayos clínicos de fase 2 para el tratamiento del edema macular en pacientes con retinopatía diabética y uveítis posterior no infecciosa.
Kiora Pharmaceuticals (NASDAQ: KPRX)는 ARVO 2025에서 새로운 DHODH 억제제인 KIO-104의 유망한 전임상 데이터를 발표했습니다. 이 연구는 망막박리 수술 후 주요 합병증인 증식성 유리체망막병증(PVR)의 흉터 형성을 현저히 줄이는 효과를 입증했습니다.
토끼 모델 연구의 주요 결과는 다음과 같습니다: 고용량 그룹(10 μg/눈)은 모든 피험자에서 흉터 형성을 완전히 차단했습니다. 저용량 그룹(1 μg/눈)은 6마리 중 2마리에서 9개의 망막 흉터가 나타나 흉터 형성이 감소했으며, 평균 흉터 길이는 43 ± 16 μm였습니다. 대조군은 6마리 중 4마리에서 20개의 망막 흉터가 발생했으며, 평균 흉터 길이는 110 ± 28 μm였습니다.
KIO-104은 현재 당뇨병성 망막병증과 후부 비감염성 포도막염 환자의 황반부종 치료를 위한 2상 임상시험 중에 있습니다.
Kiora Pharmaceuticals (NASDAQ : KPRX) a présenté des données précliniques prometteuses pour KIO-104, leur nouvel inhibiteur de DHODH, lors de l'ARVO 2025. L'étude a démontré une réduction significative de la formation de cicatrices dans le traitement de la rétinopathie vitréo-proliférative (PVR), la principale complication après une chirurgie du décollement de la rétine.
Les résultats clés de l'étude sur modèle lapin ont montré : Le groupe haute dose (10 μg/œil) a complètement empêché la formation de cicatrices chez tous les sujets. Le groupe basse dose (1 μg/œil) a montré une réduction de la formation de cicatrices avec seulement 9 cicatrices rétiniennes chez 2 des 6 lapins, avec une longueur moyenne des cicatrices de 43 ± 16 μm. Le groupe contrôle a développé 20 cicatrices rétiniennes chez 4 des 6 animaux, avec une longueur moyenne des cicatrices de 110 ± 28 μm.
KIO-104 est actuellement en essais cliniques de phase 2 pour le traitement de l'œdème maculaire chez les patients atteints de rétinopathie diabétique et d'uvéite postérieure non infectieuse.
Kiora Pharmaceuticals (NASDAQ: KPRX) präsentierte vielversprechende präklinische Daten zu KIO-104, ihrem neuartigen DHODH-Inhibitor, auf der ARVO 2025. Die Studie zeigte eine signifikante Reduktion der Narbenbildung bei der Behandlung der proliferativen vitreoretinopathie (PVR), der häufigsten Komplikation nach einer Netzhautablationsoperation.
Die wichtigsten Ergebnisse der Kaninchenstudie waren: Die Hochdosisgruppe (10 μg/Auge) verhinderte die Narbenbildung bei allen Versuchstieren vollständig. Die Niedrigdosisgruppe (1 μg/Auge) zeigte eine reduzierte Narbenbildung mit nur 9 Netzhautnarben bei 2 von 6 Kaninchen, mit einer durchschnittlichen Narbenlänge von 43 ± 16 μm. Die Kontrollgruppe entwickelte 20 Netzhautnarben bei 4 von 6 Tieren, mit einer durchschnittlichen Narbenlänge von 110 ± 28 μm.
KIO-104 befindet sich derzeit in klinischen Phase-2-Studien zur Behandlung von Makulaödem bei Patienten mit diabetischer Retinopathie und posteriorer nicht-infektiöser Uveitis.
- Complete prevention of scar formation in high dose group (100% efficacy)
- Significant reduction in scar formation and length in low dose group (p=0.04)
- KIO-104 already advancing in Phase 2 trials for macular edema, showing pipeline progress
- Addresses unmet medical need as there are no approved drugs for PVR
- Results are only from preclinical studies, requiring further clinical validation
- Small sample size of only 6 rabbits per group
Insights
Kiora's preclinical PVR data shows promise, but represents early-stage research with significant development hurdles ahead.
Kiora Pharmaceuticals has presented encouraging preclinical data for KIO-104 in treating proliferative vitreoretinopathy (PVR), an unmet medical need with no FDA-approved treatments. The in vivo rabbit model demonstrated dose-dependent efficacy, with the high dose (10 μg/eye) completely preventing scar formation in all test subjects - a critical endpoint for this condition.
This data expands the potential applications for KIO-104, which is already in Phase 2 clinical trials for macular edema. Multiple potential indications improve the compound's commercial prospects if development succeeds. KIO-104's mechanism as a DHODH inhibitor that suppresses T cell replication provides scientific rationale for its effectiveness in inflammatory eye conditions.
However, investors should recognize this represents very early-stage research. The translational gap between animal models and human efficacy is substantial - preclinical success doesn't 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 wasn't 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 PVR model addresses 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.
The complete prevention of scar formation in the high-dose group is particularly noteworthy. Current management of PVR is purely surgical, requiring complex vitreoretinal procedures often with silicone oil tamponade. A pharmacological approach that could prevent PVR would dramatically improve surgical outcomes.
KIO-104's mechanism targeting DHODH (dihydroorotate dehydrogenase) is scientifically sound. By inhibiting pyrimidine synthesis, it selectively affects rapidly proliferating cells driving the scarring process. The statistically significant reduction in scar length (43±16 μm vs. 110±28 μm in controls) and decreased inflammatory cell infiltration suggest both anti-fibrotic and anti-inflammatory effects.
However, the rabbit model, while established, doesn't fully recapitulate human disease complexity. The transition from subretinal injection in controlled experimental settings to clinical application faces multiple challenges. Additionally, intravitreal injections carry risks including endophthalmitis and retinal detachment - ironically the very condition this treatment aims to prevent complications from.
Encinitas, California--(Newsfile Corp. - May 5, 2025) - Kiora Pharmaceuticals, Inc. (NASDAQ: KPRX), ("Kiora" or the "Company") today announced the results from a preclinical study demonstrating KIO-104 significantly reduced scar formation in an established in vivo model of proliferative vitreoretinopathy (PVR). The findings further support KIO-104 as a promising therapeutic candidate for inflammatory and proliferative diseases of the retina that lead to vision threatening scarring. The presentation, titled, "KIO-104, a novel small molecule inhibitor of DHODH, effectively prevents proliferative vitreoretinopathy in a rabbit model," was presented by Romana Seda-Zehetner, MSc MScTox, Kiora's Director, Preclinical Development at the 2025 Association for Research in Vision and Ophthalmology (ARVO) meeting.
"PVR is the leading complication following retinal detachment surgery," said Eric J. Daniels, M.D., Chief Development Officer for Kiora. "This condition is driven by uncontrolled cellular proliferation, fibrosis, and inflammation. This results in scarring which may lead to repeated retinal detachments as well as progressive and permanent loss of vision. Given the reduction in scar formation and scar size observed in this study and the fact that there are no approved drugs for this condition, further development of KIO-104 in PVR is warranted."
The study evaluated the efficacy of intravitreal delivery at multiple dose levels of KIO-104, a small molecule, DHODH inhibitor, in the prevention of PVR-related scar formation. The study used an established retinal detachment model in rabbits that mimics the structural and functional disruption observed in human retinal detachment including glial reactivity, subretinal fibrosis, immune cell infiltration, and glial scar formation. By disrupting an essential molecular pathway for rapidly dividing cells, de novo biosynthesis of pyrimidine nucleotides, KIO-104 significantly reduced scar formation in a dose-dependent manner. Findings include the following:
- The high dose group (n=6) exhibited complete prevention of scar formation in all rabbits.
- The low dose group (n=6) exhibited a reduction in scar formation. Two of the six rabbits developed a total of nine retinal scars, with a significant (p=0.04) reduction in mean ± SEM scar length to 43 ± 16 µm.
- The control group (n=6) exhibited scar formation in four out of six animals resulting in 20 retinal scars, with a mean ± SEM scar length of 110 ± 28 µm.
Study design:
Retinal detachments were induced in Dutch Belted rabbits (n=6 per group) by subretinal injection of ~500 µL of
About KIO-104
KIO-104 is a small molecule DHODH inhibitor that works by suppressing T cell replication and function. Suppressing T cell numbers and activity could provide a novel approach to reducing or eliminating the underlying proliferative and inflammatory environment that often leads to scar formation. 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.
About Kiora Pharmaceuticals
Kiora Pharmaceuticals is a clinical-stage biotechnology company developing advanced therapies for retinal disease. We target critical pathways underlying retinal diseases using innovative small molecules to slow, stop, or restore vision loss. 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. KIO-104 is being developed for the treatment of retinal inflammation. It is a next-generation, non-steroidal, immuno-modulatory, and small-molecule inhibitor of dihydroorotate dehydrogenase (DHODH).
In addition to news releases and SEC filings, we expect to post information on our website, www.kiorapharma.com, and social media accounts that could be relevant to investors. We encourage investors to follow us on X and LinkedIn as well as to visit our website and/or subscribe to email alerts.
Forward-Looking Statements
Some of the statements in this press release are "forward-looking" and are made pursuant to the safe harbor provision of the Private Securities Litigation Reform Act of 1995. These "forward-looking" statements include statements relating to, among other things, Kiora's ability to execute on development and commercialization efforts and other regulatory or marketing approval efforts pertaining to Kiora's development-stage products, including KIO-104 and KIO-301, as well as the success thereof, with such approvals or success may not be obtained or achieved on a timely basis or at all, the sufficiency of existing cash and short-term investments on hand to fund operations for specific periods, the ability to timely complete planned initiatives for 2025, including Phase 2 clinical development of KIO-301 and KIO-104, the completion of enrollment and the timing of topline results from the ABACUS-2 Phase 2 trial, the potential for KIO-301 to be the first treatment options for patients with inherited degenerative diseases like RP, the potential for KIO-104 to reduce inflammation, the timing of topline results from the Phase 2 KLARITY trial of KIO-104, the potential for KIO-104 to apply to other retinal inflammatory diseases, and expected trends for research and development and general and administrative spending in 2025. These statements involve risks and uncertainties that may cause results to differ materially from the statements set forth in this press release, including, among other things, the ability to conduct clinical trials on a timely basis, market and other conditions and certain risk factors described under the heading "Risk Factors" contained in Kiora's Annual Report on Form 10-K filed with the SEC on March 25, 2025 or described in Kiora's other public filings. Kiora's results may also be affected by factors of which Kiora is not currently aware. The forward-looking statements in this press release speak only as of the date of this press release. Kiora expressly disclaims any obligation or undertaking to release publicly any updates or revisions to such statements to reflect any change in its expectations with regard thereto or any changes in the events, conditions, or circumstances on which any such statement is based, except as required by law.
Contacts:
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