Kiora Pharmaceuticals, Inc. has obtained exclusive development and commercialization rights, outside Asia, to KIO-401, a late-stage neuroprotective, oral small-molecule calpain inhibitor, from Senju Pharmaceutical Co., Ltd. KIO-401 is being developed as a potential treatment for central retinal artery occlusion (CRAO).
According to a company press release, Senju has completed both phase 2 and phase 3 clinical studies of KIO-401 in patients with CRAO in Japan. KIO-401 (mitucapistat), designated by Senju as SJP-0008 in Japan and Asia, is an oral neuroprotective small molecule designed to inhibit activated calpain, a calcium-dependent protease implicated in cellular injury following ischemia. By inhibiting activated calpain, KIO-401 is intended to reduce downstream cellular damage and preserve visual function following ischemic injury.
In the randomized phase 2a study in Japan conducted by Senju and its partners, KIO-401 demonstrated a statistically significant improvement from baseline in Early Treatment Diabetic Retinopathy Study visual acuity compared with a prospective, observational registry (P=.0398). Senju completed a randomized, double-masked phase 3 study in Japan, which demonstrated improvement in best-corrected visual acuity, including a statistically significant improvement among patients who were legally blind at baseline according to World Health Organization criteria (P=.0195).
Kiora said it intends to build upon the clinical experience generated by Senju in Japan through a US-focused, multinational phase 3 registration trial in CRAO. The company is targeting initiation in 2027, subject to funding and regulatory alignment. The planned randomized, double-masked, controlled trial will evaluate the efficacy and safety of KIO-401 in patients with acute CRAO, with visual function outcomes expected to play a central role in the assessment of treatment benefit. The final study design, including enrollment criteria, primary endpoint, and sample size, will be determined following discussions with regulatory authorities. Enrollment is estimated to exceed 100 patients.
Kiora also plans to advance KIO-401 into a phase 2b clinical trial for nonarteritic anterior ischemic optic neuropathy (NAION). According to the company, the shared involvement of ischemia-related cellular injury and calpain activation in CRAO and NAION provides a scientific rationale for evaluating KIO-401 in both indications. Initiation of the NAION study is targeted for 2028, subject to funding and regulatory considerations.
Kiora also intends to evaluate opportunities to expand the KIO-401 platform into additional ophthalmic indications in which calpain-mediated cellular injury may contribute to disease progression, including glaucoma. These potential indications would require further preclinical and clinical evaluation, according to the company.
The agreement builds on an existing relationship between the companies involving KIO-301, Kiora's photoswitch therapy in development for advanced retinitis pigmentosa.
As KIO-301's phase 2 ABACUS-2 trial completes enrollment, Kiora expects to transition clinical resources to KIO-401's phase 3 CRAO program.
As part of its portfolio optimization strategy, Kiora announced that it will discontinue research and development of KIO-104. Kiora will report data from enrolled patients in the KLARITY clinical trial and consider partnering and out-licensing opportunities for the asset, the company said in the press release. RP