Posted: 14 November 2025
A new blood test designed to better guide ovarian cancer therapy was reported to have shown strong promise, after researchers identified a simple way to determine which women were more likely to benefit from PARP inhibitor treatment. The advance emerged from the four-year SOLACE2 clinical trial, conducted across 15 Australian hospitals and jointly led by RMIT University, WEHI and the University of Sydney’s NHMRC Clinical Trials Centre, with coordination by the Australia New Zealand Gynaecological Oncology Group (ANZGOG).
“It was demonstrated in SOLACE2 that a new immune-based test could more accurately indicate which women would respond to PARP inhibitors,” said Distinguished Professor Magdalena Plebanski, co-senior author and head of RMIT’s Accelerator for Translational Research and Clinical Trials Centre. Her team reported that the test measured changes in immune biomarkers reflecting the movement of tumour-fighting immune cells and key inflammatory processes, forming a straightforward blood-based signature.
The trial had originally been established to assess whether stimulating the immune system could enhance the effectiveness of PARP inhibitor therapy, which disrupts cancer cells’ ability to repair damaged DNA by blocking the PARP enzyme. During the study, researchers also evaluated the new companion diagnostic, finding that RMIT-patented biomarkers may provide a more precise indication of likely treatment benefit than the current homologous recombination deficiency (HRD) test.
The HRD test requires tumour tissue and complex genomic analysis and may not reflect real-time cancer behaviour, whereas the new immune-response measure was shown to more closely align with patient outcomes. WEHI joint-senior author Professor Clare Scott AM said the findings highlighted the crucial role of immune cell behaviour in determining treatment response, particularly the ability of effector T cells to move into the tumour.
The SOLACE2 trial also revealed that three months of immune priming followed by PARP inhibitor therapy and immunotherapy delayed recurrence, although further validation was required. Study leaders emphasised that the newly identified test now required urgent clinical confirmation before it could be made available to patients.
Collaborators noted that ongoing national coordination through ANZGOG had been essential to the project, underscoring the importance of partnerships in advancing personalised cancer care.
