Researchers have reported encouraging 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 works in this one.
Scientists now believe this approach could change that outlook.
VIR-5500 is an engineered antibody that redirects killer T-cells toward tumour cells.
The drug activates mainly inside the tumour, which limits harmful inflammation.
This design may also allow longer circulation and fewer doses.
Fifty-eight men joined the phase-one trial after standard treatments failed.
Most participants experienced only mild side effects.
Researchers measured prostate-specific antigen levels to assess response.
Among patients on the highest dose, most saw PSA levels fall sharply.
Several recorded reductions of more than ninety percent.
Tumour scans also showed direct shrinkage in some cases.
One patient with liver spread saw multiple cancer lesions disappear.
Scientists described the findings as unprecedented for an “immune-cold” cancer.
They stressed that larger trials must confirm safety and long-term benefit.
Cancer specialists called the results highly promising.
They said the therapy could open a new drug class for prostate cancer.
Further studies will test its effectiveness in broader patient groups.
