A groundbreaking new treatment for advanced prostate cancer has demonstrated the ability to halt and even shrink tumours, according to remarkable clinical trial results. Early tests of this innovative immunotherapy, which leverages the body's own immune system to combat cancer, revealed disease regression in nearly half of the male participants.
Overcoming Previous Limitations
Until now, immunotherapy approaches had largely failed to prove effective for prostate cancer patients, typically resulting in minimal tumour reduction or severe adverse effects. However, the new drug, designated VIR-5500, incorporates a sophisticated 'cloaking device' mechanism. This ensures the treatment remains inactive until it specifically reaches the tumour site, thereby significantly reducing the risk of side-effects.
Medical experts have stated that these findings raise genuine hopes for a potential cure, 'in the not-too-distant future,' for individuals whose cancer has already metastasized. Prostate cancer remains the most prevalent cancer among British men, with approximately 55,000 new cases diagnosed annually. High-profile patients include Olympic cycling champion Sir Chris Hoy, aged 49, who is living with a terminal diagnosis.
Detailed Trial Findings
The research was conducted by a team led by the Institute of Cancer Research (ICR) and the Royal Marsden NHS Foundation Trust. They tested 58 men with advanced prostate cancer that had ceased responding to conventional treatments. The team, under the leadership of Professor Johann de Bono, found that almost half, specifically 45 per cent, of the patients experienced tumour shrinkage.
Furthermore, 88 per cent of all patients recruited from eight international sites reported only very mild side-effects. These results were presented at the American Society of Clinical Oncology Genitourinary Cancers Symposium in San Francisco.
In a subgroup of 17 patients who received the highest dose of the drug, half (53 per cent) witnessed a 90 per cent drop in their prostate-specific antigen (PSA) levels—a key blood marker for prostate disease. Additionally, 82 per cent of this group saw their PSA levels halved.
Mechanism of Action
Classified as a 'T-cell engager,' VIR-5500 operates by binding simultaneously to the body's immune T-cells and to a specific protein found on prostate cancer cells. This binding action brings the T-cells into direct contact with the cancer cells, regardless of their location in the body, thereby enabling a targeted immune attack.
The drug's unique 'cloaking device' also allows it to circulate in the bloodstream for an extended period, which means fewer doses are required for treatment. The study was funded by Vir Biotechnology.
Future Prospects
Professor Johann de Bono confirmed that the drug will now advance to larger-scale clinical trials. He added, 'There is certainly hope that drugs such as this will increase the likelihood of a cure, even from advanced prostate cancer that has already spread, in the not-too-distant future.'
This development aligns with broader efforts to improve prostate cancer care, notably including the Daily Mail's campaign spanning more than two decades for better treatment and awareness.
