Experimental E8 nanobody suppresses tumor growth in preclinical models with minimal toxicity.
Singapore researchers are exploring a different way to fight advanced cancer that has spread to the abdominal lining. Instead of attacking cancer cells directly, their experimental therapy targets proteins in the surrounding fluid that help tumors grow.
Researchers Map Tumor-Fueling Abdominal Fluid
A team led by the National Cancer Centre Singapore analyzed 397 ascites samples spanning 21 primary cancer types, in what NCCS describes as one of the world’s largest datasets of its kind. Ascites is fluid that can accumulate in the abdomen of patients with peritoneal metastases, a late-stage condition in which cancer has spread to the abdominal lining. Researchers identified two proteins, PAI-1 and S100A10, as key drivers of tumor growth within this fluid environment.
E8 Nanobody Targets PAI-1
The scientists selected PAI-1 as a treatment target and developed a nanobody called E8. Nanobodies are smaller antibody-derived molecules that researchers believe may have lower immunogenicity and toxicity risks than conventional antibodies. Rather than targeting tumor cells directly, E8 is designed to interfere with biological signals in the surrounding fluid that promote tumor growth.
Tumor Growth Suppressed in Preclinical Models
E8 was tested in laboratory cancer cells, mouse models, and human tumor tissue grown in patients’ ascites. Across all three preclinical systems, NCCS reported that the nanobody suppressed tumor growth with minimal toxicity. The findings were published in the peer-reviewed journal Molecular Cancer in September 2026. The treatment has not yet been proven safe or effective in human patients.
Advanced Disease Has Few Treatment Options
Peritoneal metastases can occur when cancers originating in organs such as the stomach, colon, or ovaries spread to the abdominal lining. NCCS reports a median survival of under nine months for patients with the condition, although outcomes vary depending on the underlying cancer and individual circumstances. One existing treatment approach is cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (HIPEC), which involves removing visible tumors and delivering heated chemotherapy into the abdominal cavity. According to NCCS researcher Associate Professor Johnny Ong, about nine in 10 patients are typically unsuitable for this procedure.
Researchers Aim for First Human Trial
The team is now advancing E8 toward clinical-grade development through a new biologics program called the Melyorax Initiative. Researchers are also developing a biomarker test intended to identify patients with elevated PAI-1 levels who may be more likely to benefit. Senior author Associate Professor Johnny Ong told The Straits Times that the team hopes to begin a first-in-human clinical trial in about five years.
The Singapore research provides a new experimental strategy for treating advanced cancers that spread to the abdominal lining by targeting the tumor-supporting environment rather than only the cancer cells themselves. For Singaporeans, it highlights locally led translational cancer research moving toward clinical testing. For Indonesians and other regional patients, its broader significance will depend on whether E8 eventually proves safe and effective in human trials.
Sources: Straits Times (2026) , NCCS SG (2026)
Keywords: Singapore Cancer Research, E8 Nanobody, Peritoneal Metastases, Ascites Cancer Treatment, PAI-1 Protein, National Cancer Centre Singapore
