Researchers have reported promising early results for a new prostate cancer treatment.
The experimental drug VIR-5500 shrank tumours in several patients with advanced disease.
Prostate cancer affects about 1.5 million men worldwide each year.
Immunotherapy has transformed other cancers but rarely benefits this one.
VIR-5500 uses engineered antibodies to link killer T-cells directly to tumour cells.
The drug activates mainly inside the tumour, which reduces harmful inflammation.
It can also remain in the bloodstream longer, allowing fewer doses.
Fifty-eight men whose cancer resisted standard therapies joined the phase one trial.
Most participants experienced only mild side effects.
Researchers measured prostate-specific antigen levels to assess response.
At the highest dose, 82% of patients saw PSA fall by at least half.
More than half recorded drops of ninety percent or greater.
Doctors also observed tumour shrinkage in several men with measurable disease.
One patient with liver metastases showed complete disappearance of multiple lesions.
Scientists called the findings unprecedented for an “immune-cold” cancer.
They now plan larger trials to confirm safety and long-term benefit.
Independent experts described the results as highly encouraging.
They stressed the need for broader studies across diverse patient groups.
Researchers hope the treatment could extend survival and eventually lead to cures.
