A new experimental targeted alpha-particle therapy (TAT) has shown strong anti-tumor activity against ovarian cancer in preclinical research. The treatment combines an antibody that targets Folate Receptor 1 (FOLR1), a protein highly expressed in ovarian cancer, with the radioactive isotope Actinium-225, which delivers powerful alpha radiation directly to tumor cells.
Researchers found that ovarian cancer had the highest FOLR1 levels among all cancer types and that the therapy accumulated heavily in tumors while largely sparing healthy tissues.
In mouse studies, a low-dose, split-treatment approach produced a 100% response rate, with 40% of animals experiencing complete tumor disappearance and 80% surviving long term. The therapy also significantly outperformed the FDA-approved ovarian cancer drug mirvetuximab soravtansine, extending median survival from 30 days to 100 days.
Although the results are promising, the study was conducted in a single mouse model, and higher single doses caused radiation-related toxicity. Some tumors also returned months after treatment.
Researchers say the findings support further development of this highly targeted radiopharmaceutical for future clinical trials in patients with ovarian cancer.