Kenai Therapeutics Announces First Patient Dosed in Phase 1 REPLACE™ Clinical Trial of Neuron Replacement Cell Therapy RNDP-001 for Idiopathic Parkinson's Disease

Fast Track designation granted by U.S. FDA

Initial safety, tolerability and brain imaging data from the trial are expected in 2026

SAN DIEGO, Dec. 15, 2025 /PRNewswire/ -- Kenai Therapeutics, a clinical-stage biotechnology company pioneering next generation approaches to cure neurological conditions, today announced that the first patient has been dosed in its Phase 1 REPLACE™ clinical trial of RNDP-001 for the treatment of moderate to moderate-severe idiopathic Parkinson's disease. This milestone follows the clearance of Kenai's Investigational New Drug (IND) application by the U.S. Food and Drug Administration, allowing the company to initiate clinical evaluation of RNDP-001, an off-the-shelf, allogeneic neuron replacement cell therapy designed to restore motor function by replacing the dopamine-producing neurons lost to Parkinson's disease. RNDP-001 has also been granted Fast Track designation by the U.S. FDA in recognition of the urgent need for new therapies in Parkinson's disease. Fast Track designation is intended to accelerate development and review of RNDP-001.

"While most Parkinson's disease treatments focus on symptom management, RNDP-001 aims to replace lost neurons, repair damaged neural circuits and restore motor function for patients with moderate to moderate-severe forms of the disease. By moving beyond symptom control to address the root cause of disease, our goal is to offer patients a future with improved motor function and better overall quality of life," said Nick Manusos, Chief Executive Officer of Kenai Therapeutics. "This milestone marks an important step forward for Kenai and for families impacted by Parkinson's."

The Phase 1 REPLACE™ study is an open-label, multi-center trial evaluating the safety and tolerability of RNDP-001, as well as brain imaging evidence of cell survival and engraftment, in adult patients with moderate to moderate-severe idiopathic Parkinson's disease, a condition with unknown cause.

The therapy into targeted areas of the brain is delivered via a precision neurosurgical procedure, replacing dopamine-producing cells. The trial will enroll up to 12 patients with moderate to moderate-severe idiopathic Parkinson's disease. Initial safety, tolerability and brain imaging data from all 12 patients are expected in 2026.

"Initiating this first-in-human trial represents the culmination of decades of foundational research in regenerative neuroscience," said Howard Federoff, M.D., Ph.D., Chief Medical Officer and Executive Vice President of Corporate Medicine and Science at Kenai Therapeutics. "What sets RNDP-001 apart is not just the depth of research behind it, but also its potential to intervene at the level of disease by replacing the dopaminergic neurons that are central to Parkinson's progression. It is a privilege to help advance a therapy that could fundamentally shift how we treat this complex condition."

Kenai's therapy is built on a proprietary induced pluripotent stem cell (iPSC) platform that uses donor-derived, cryopreserved cells to enable an off-the-shelf product that can be scaled to address a growing global need. Through an exclusive and proprietary manufacturing partnership with FUJIFILM Cellular Dynamics, Inc., Kenai offers high-quality, reproducible production of dopamine progenitor cells for clinical use.

About FDA Fast Track Designation

The FDA's Fast Track program is designed to facilitate the development and expedite the review of therapies that treat serious or life-threatening conditions and have the potential to address unmet medical needs. Programs granted Fast Track designation benefit from more frequent interactions with the FDA, eligibility for Accelerated Approval and Priority Review, and the option to submit a New Drug Application on a rolling basis.

About Kenai Therapeutics

Kenai Therapeutics is a clinical-stage biotechnology company pioneering next generation approaches to cure neurological conditions. By leveraging a proprietary, Nobel Prize-winning iPSC platform, Kenai is developing off-the-shelf, allogeneic neuron replacement and gene-modified cell therapies designed to be disease-modifying. Kenai's lead candidate, RNDP-001, is in Phase 1 clinical development for moderate to moderate-severe forms of idiopathic Parkinson's disease. The company's additional programs target inherited and genetically driven subtypes of Parkinson's disease and other neurological conditions, with the goal of delivering long-lasting restoration of function. Kenai's exclusive manufacturing partnership with FUJIFILM Cellular Dynamics, Inc., enables scalable, cryopreserved production of high-potency cell therapies. Founded in 2022, Kenai is backed by leading life science investors and is headquartered in San Diego, CA. For more information, visit www.kenaitx.com and follow us on LinkedIn and Bluesky.

About FUJIFILM Cellular Dynamics, Inc.

FUJIFILM Cellular Dynamics, Inc. is a leading developer and manufacturer of human iPSCs and iPSC-derived cells utilized in drug discovery, contract development and manufacturing services for cell therapies. For its partners, FUJIFILM Cellular Dynamics utilizes its iPSC platform to advance the progress of therapeutic candidates in the clinic and provides contract development and manufacturing (CDMO) services. In addition to cell therapy, FUJIFILM Cellular Dynamics also offers life science research tools including the company's inventoried iCell® products, which are available in almost any cell type and are sourced from multiple cell lines which can be applied for target identification as well as toxicity testing. The company also offers custom cell services and cell banking. FUJIFILM Cellular Dynamics' goal is to leverage the vast utility of iPSCs to advance human health and improve the quality of life for patients around the world. For more information, please visit: www.fujifilmcdi.com.

SOURCE Kenai Therapeutics/BIOCOM