SINGAPORE – Singapore researchers have discovered that a Singapore-developed cancer drug, originally developed at A*STAR Institute of Molecular and Cell Biology (A*STAR IMCB), shows potential as a new treatment approach for two leading causes of blindness worldwide.
In pre-clinical studies published in Nature Communications, PRL3-zumab effectively reduced leakage from damaged blood vessels—a major cause of vision loss—showing promise as a potential new treatment for patients whose conditions do not respond well to current therapies.
The findings, from scientists at A*STAR IMCB and local biotech firm Intra-ImmuSG (IISG), point to a new option for treating wet age-related macular degeneration (AMD) and diabetic retinopathy, two of the most common causes of vision loss globally.
Addressing Limitations of Current Treatments
Currently, patients with these sight-threatening diseases require monthly injections directly into the eye—a procedure that carries risks of infection and lens damage. Additionally, up to 45% of patients do not respond adequately to these treatments, highlighting the need for alternative approaches.
PRL3-zumab offers a different approach. Unlike current therapies, it can be administered intravenously. In pre-clinical studies, intravenous delivery showed an 86% greater reduction in abnormal blood vessel leakage compared to intravitreal injections, potentially preventing vision loss associated with these diseases.
The study findings indicate that intravenous delivery achieved more sustained therapeutic levels in the eye compared to traditional eye injections, while potentially avoiding injection-related complications.
The research team is now preparing for human trials following approval from Singapore’s Health Sciences Authority (HSA), granted on 16 June 2025. Clinical trials are expected to begin by late 2025, marking an important milestone in evaluating PRL3-zumab's potential as an ophthalmology treatment in Singapore.
PRL3-zumab has already completed Phase II trials in cancer patients with a favourable safety profile—data that provides useful background as researchers explore its application for eye diseases.
From Cancer Research to Ophthalmology Applications
The journey of PRL3-zumab illustrates how insights from cancer research can lead to breakthroughs in other medical fields. Professor Qi Zeng, Senior Principal Scientist at A*STAR IMCB and founder of IISG, initially identified the PRL3 protein in 1998 as a key factor in cancer metastasis. Subsequent studies revealed PRL3’s surprising role in eye diseases, opening a new frontier for treatment.
“When I first identified PRL3 over two decades ago, I never imagined that our cancer research could also provide hope for patients facing blindness,” said Professor Qi Zeng, senior author on the study. “Seeing PRL3-zumab now potentially transform treatment for devastating eye conditions shows how fundamental scientific discoveries can lead to life-changing outcomes.”
"The repurposing of PRL3-zumab offers the possibility of a faster, more cost-effective and potentially safer path to developing treatments for these eye diseases," said Associate Professor Xinyi Su, Executive Director of A*STAR IMCB, also a co-author on the study. "This is made possible through the close collaborations in Singapore between our scientists, clinicians and clinician scientists."
Study citation: Ang, K.H., Thura, M., Tan, Q.S.W. et al. PRL3-zumab as an anti-angiogenic therapy in neovascular eye diseases. Nature Communications 16, 4791 (2025). https://doi.org/10.1038/s41467-025-59929-2
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About A*STAR Institute of Molecular and Cell Biology
The A*STAR Institute of Molecular and Cell Biology (A*STAR IMCB) is a premier research institute whose mission is to harness biology for transformational bio-therapeutics and diagnostics. With a strong emphasis on collaboration with stakeholders across the ecosystem in Singapore, A*STAR IMCB aims to achieve scientific excellence and continues to nurture the next generation of scientists in order to create growth and enhance lives. For more information about A*STAR IMCB, please visit www.a-star.edu.sg/imcb.
About the Agency for Science, Technology and Research
The Agency for Science, Technology and Research (A*STAR) is Singapore's lead public sector R&D agency. Through open innovation, we collaborate with our partners in both the public and private sectors to benefit the economy and society. As a Science and Technology Organisation, A*STAR bridges the gap between academia and industry. Our research creates economic growth and jobs for Singapore, and enhances lives by improving societal outcomes in healthcare, urban living, and sustainability. A*STAR plays a key role in nurturing scientific talent and leaders for the wider research community and industry. A*STAR’s R&D activities span biomedical sciences to physical sciences and engineering, with research entities primarily located in Biopolis and Fusionopolis. For ongoing news, visit www.a-star.edu.sg.
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About Intra-ImmuSG (IISG)
Intra-ImmuSG Pte Ltd (IISG) is a Phase II clinical-stage biotechnology company focused on pioneering cancer immunotherapies that selectively target tumour-specific proteins with minimal side effects. A spin-off from A*STAR IMCB, IISG is developing PRL3-zumab, a first-in-class antibody that exemplifies a novel strategy to target intracellular oncoproteins through immune-mediated mechanisms. For more information about IISG, please visit https://www.intra-immusg.com.
Journal
Nature Communications
Article Title
PRL3-zumab as an anti-angiogenic therapy in neovascular eye diseases