An international clinical trial involving patients and research teams in Ireland has reported that adding darolutamide to radiation therapy and hormone therapy reduces the risk of prostate cancer spreading in people with very high-risk localised or locally advanced disease.
The first planned analysis of the DASL-HiCaP trial was presented at a Presidential Symposium at ESMO Congress 2026 in Madrid.
Cancer Trials Ireland is the EU and UK sponsor for the study, which recruited 1,106 participants worldwide. This included 36 patients in Ireland and 59 in the UK, with recruitment in the region taking place between July 2021 and August 2023.
What the trial investigated
People with very high-risk localised or locally advanced prostate cancer remain at risk of their cancer returning or spreading despite treatment.
DASL-HiCaP investigated whether adding darolutamide, an oral androgen receptor inhibitor, to radiation therapy and androgen deprivation therapy could improve outcomes. Androgen deprivation therapy reduces testosterone levels. Participants were randomly assigned to receive either darolutamide or a matching placebo alongside their standard treatment.
The analysis found that participants receiving darolutamide experienced longer metastasis-free survival than those receiving placebo. It also observed fewer prostate cancer deaths and fewer rises in prostate-specific antigen levels indicating recurrence.
Follow-up is continuing to assess longer-term outcomes, including overall survival.
Cancer Trials Ireland’s role
As EU and UK sponsor, Cancer Trials Ireland supported the delivery of the study across the region. Prof Ray McDermott and Prof Paul Kelly led the study in Ireland.
The trial was open at nine sites in Ireland. Together, patients and research teams in Ireland and the UK contributed 95 participants to the international study.
Prof Paul Kelly, Consultant Radiation Oncologist at Bon Secours Hospital Cork and Co-Chair of the Cancer Trials Ireland Genitourinary Disease Specific Sub-Group, said:
“These findings show that adding darolutamide to standard radiation therapy and hormone therapy reduces the risk of cancer recurring in people with very high-risk prostate cancer.”
International collaboration
DASL-HiCaP was jointly led by the Australian and New Zealand Urogenital and Prostate Cancer Trials Group (ANZUP) and the Sydney Clinical Trials Centre at the University of Sydney, in collaboration with Cancer Trials Ireland and research partners in Canada and the United States. The trial was funded by Bayer.
Cancer Trials Ireland CEO Angela Clayton-Lea said:
“A diagnosis of very high-risk local and locally advanced prostate cancer is challenging for patients and their families, particularly given the risk of the cancer returning or spreading despite treatment. These findings are encouraging and contribute to our understanding of how outcomes for people affected by this disease may be improved.”
Cancer Trials Ireland thanks the patients who volunteered to participate and the investigators and research teams whose work made this international study possible.