A research team at the Korea Advanced Institute of Science and Technology (KAIST) has developed a pioneering therapy capable of restoring vision by regenerating damaged retinal nerves—marking a significant milestone in the treatment of degenerative eye diseases. This breakthrough offers renewed hope to more than 300 million people worldwide who are at risk of blindness due to various retinal conditions.
Led by Professor Jin Woo Kim from the Department of Biological Sciences, the KAIST team discovered a method to achieve both retinal regeneration and vision recovery in mammalian models. The therapy targets a protein called PROX1 (prospero homeobox 1), which normally inhibits retinal repair processes. By neutralizing this protein, the team enabled damaged retinas to regenerate and restore visual function—an achievement that, until now, had not been possible in mammals.
In preclinical trials using a mouse model of retinitis pigmentosa, researchers were able to induce long-term retinal regeneration by blocking PROX1 activity. These effects persisted for more than six months, making it the first recorded case of sustainable neural regeneration in a mammalian retina.
The key to this advancement lies in the behavior of Müller glia cells, which are support cells in the retina. In cold-blooded animals such as fish, these cells can revert into neural progenitor cells following injury, eventually regenerating damaged neurons. However, in mammals, this regenerative response is typically suppressed.
The KAIST team identified that PROX1 protein plays a central role in blocking this regenerative ability in mammals. Rather than producing the protein internally, mammalian Müller glia absorb PROX1 secreted from damaged retinal neurons. This external accumulation of PROX1 prevents the cells from re-entering a regenerative state.
To counter this, the team developed a gene therapy approach using adeno-associated virus (AAV) vectors to deliver an antibody that neutralizes PROX1. This antibody, developed in collaboration with Celliaz Inc.—a biotech startup spun out of Professor Kim’s laboratory—was shown to eliminate the inhibitory effects of PROX1. In treated mice, the retinal structure was restored and visual function significantly improved.
The antibody, named CLZ001, is currently undergoing final optimization. Celliaz Inc. is preparing for preclinical studies with the aim of initiating clinical trials by 2028. The therapy is being positioned as a treatment for various currently incurable degenerative retinal diseases, including retinitis pigmentosa and age-related macular degeneration.
The work represents a major advance in regenerative medicine and demonstrates how targeting specific molecular inhibitors can unlock dormant repair mechanisms in the human body. With continued development, this technology could redefine treatment strategies for vision loss and improve the quality of life for millions facing irreversible blindness.
By Impact Lab
