Innovative Cancer Drug PRL3-zumab Set to Begin Trials for Vision Loss

SINGAPORE — A groundbreaking cancer treatment developed locally, known as PRL3-zumab, is poised to begin human trials aimed at preventing vision loss in patients suffering from wet age-related macular degeneration (AMD) and diabetic retinopathy. This innovative drug, which will be administered intravenously, represents a significant shift from existing treatments that require injections directly into the eye. The trials are set to commence by late 2025 following the approval from Singapore’s Health Sciences Authority on June 16, 2025.

The research leading to this development has been conducted over two decades by a team at the A*Star Institute of Molecular and Cell Biology (IMCB) and its biotech spin-off, Intra-ImmuSG. Professor Qi Zeng, a senior principal scientist at A*Star and the founder of Intra-ImmuSG, has been instrumental in the drug's development. "PRL3-zumab targets only diseased tissues, ensuring a safe profile for patients," she stated, reflecting on her discovery of the PRL3 protein in 1998, which has been linked to various cancers.

Pre-clinical studies published in the journal Nature Communications demonstrated that PRL3-zumab significantly reduced leakage from damaged blood vessels — a primary cause of vision loss associated with both AMD and diabetic retinopathy. Dr. David Ang Koon Hwee, a senior scientist at A*Star, emphasized the advantages of intravenous administration, noting that it achieved an 86 percent greater reduction in abnormal vessel leakage compared to traditional injection methods. "This drug can reduce the leakage as effectively as repairing a broken water pipe," he explained, underscoring the limitations of current therapies, which cannot be administered intravenously due to toxicity issues.

The drug has already undergone Phase II trials in Singapore, the United States, China, and Malaysia, with a strong safety profile observed among 210 advanced cancer patients. The upcoming trial will involve 15 participants and aims to evaluate the drug's efficacy as an alternative to the current standard care requiring frequent intraocular injections.

Both conditions targeted by PRL3-zumab are among the leading causes of vision impairment globally. Wet AMD, characterized by the growth of abnormal blood vessels under the retina, and diabetic retinopathy, which results from diabetes-related damage to the retinal blood vessels, currently affect millions. According to the World Health Organization, approximately 196 million people worldwide suffer from diabetic retinopathy, while AMD affects an estimated 20 million individuals in the United States alone.

The implications of successful trials for PRL3-zumab could be profound, potentially offering a more effective treatment option to patients who do not respond adequately to existing therapies. As Dr. Ang poignantly noted, his motivation to innovate was personal, stemming from witnessing his father endure the burdens of regular intraocular injections for diabetic eye complications.

As the healthcare community anticipates the commencement of these trials, the results could pave the way for a new frontier in the treatment of vision loss due to these debilitating conditions. The ongoing research highlights Singapore's growing reputation as a hub for innovative medical solutions and underscores the importance of continued investment in local biomedical research.

In conclusion, the journey of PRL3-zumab from laboratory research to potential clinical application illustrates the dynamic interplay between cancer treatment and ophthalmological care, offering hope to millions facing the threat of vision loss. Further studies will be essential to establish its effectiveness in clinical settings.