ANZUP at ASCO 2025 – ENZAMET
ENZAMET
Poster presented by Dr Alison Zhang. ANZUP’s practice changing ENZAMET trial showed that people diagnosed with metastatic hormone sensitive prostate cancer on testosterone suppression therapy who received the androgen receptor pathway inhibitor enzalutamide, had a longer overall survival compared to those receiving non-steroidal anti-androgen (NSAA) therapy. On the weekend, Dr Zhang presented the latest findings from this trial with a median follow-up of at least 8 years to understand the long-term efficacy and safety of enzalutamide. The results showed participants lived longer on enzalutamide with median overall survival 8.0 years compared to those on NSAA’s who had a median overall survival of 5.8 years. Falls and fractures were higher for participants on enzalutamide, but cardiac and cerebrovascular events had a similar frequency. These results show that enzalutamide treatment results in significant survival benefit for those diagnosed with metastatic hormone sensitive prostate cancer, but the side effects of treatment impacting bone health need consideration and effective management.
Prognostic value of PSMA-PET against CHAARTED criteria in an ENZAMET sub-cohort
Poster presented by Prof Louise Emmett. CHAARTED criteria on conventional imaging (CT and bone scan) is an important prognostic biomarker in metastatic hormone sensitive prostate cancer (mHSPC) that is used to guide treatment intensification; however, clinicians are increasingly using PSMA PET/CT scans in lieu of conventional imaging for staging of prostate cancer. PSMA PET/CT criteria for poor prognostic mHSPC are poorly defined. In a sub-study of ENZAMET, 100 participants (51 enzalutamide, 49 control NSAA) who had PSMA-PET were used to identify features on these scans that correlate to progression free and overall survival. The results showed that total tumour volume on PSMA-PET (PSMA-TTV) is associated with progression free survival in mHSPC and could be potentially used as a prognostic tool.
Poster presentation by Prof Lisa Horvath (pictured with fellow author Prof Anthony Joshua). In another sub-study of the ENZAMET trial, blood based immune and metabolic biomarkers were assessed for their prognostic and predictive ability. At ASCO, Professor Horvath presented the results that showed that circulating IL8, IGFBP1 and the IGF/IGFBP1 ratio was prognostic for overall survival and several pro-inflammatory, anti-tumour and macrophage-associated biomarkers were associated with poorer clinical outcomes in mHSPC. None of the markers were predictive of response to enzalutamide. This study yielded important insights into the development of immune and metabolic prognostic and predictive biomarkers for prostate cancer.
