Surgery with or Without Darolutamide in High-risk and/or Locally Advanced Prostate Cancer: The SUGAR (CCAFU-PR2) Phase 2 Trial Rationale and Protocol

Background: High-risk prostate cancer (PCa) patients frequently experience recurrence and progression after radical prostatectomy (RP). Neoadjuvant androgen deprivation therapy (ADT) has not demonstrated a clear oncological benefit and is not currently recommended.

Objective: The SUGAR trial is the first phase 2, randomised, controlled, multicentre, noncommercial, open-label study investigating single-agent perioperative darolutamide compared with the standard of care (ie, upfront RP, without neoadjuvant ADT).

Design, setting, and participants: SUGAR aims to randomise 240 men affected by nonmetastatic PCa, with the major eligibility criteria being International Society of Urological Pathology grade group ≥4, seminal vesicle invasion at magnetic resonance imaging and/or clinically node-positive disease. Patients in the experimental arm will undergo neoadjuvant darolutamide monotherapy, RP, and adjuvant darolutamide, completing 9 mo of treatment.

Outcome measurements and statistical analysis: The primary endpoint is noncurable recurrence-free survival, an innovative and clinically meaningful measure; the secondary endpoints encompass safety; recurrence-free, metastasis-free, and overall survival; pathological response; and quality of life. A predictive biomarker analysis will also be performed.

Results and limitations: Initial data suggest that intensified neoadjuvant treatment with androgen receptor signalling inhibitors (ARSIs) is associated with a sustained pathological response and may improve outcomes, via tumour downstaging and micrometastasis eradication. ARSI monotherapy could further enhance tolerability.

Conclusions: SUGAR will provide efficacy and safety information on perioperative darolutamide monotherapy compared with upfront RP, in a contemporary high-risk PCa population undergoing surgery.

Patient summary: The on-going SUGAR clinical trial evaluates 9 mo of darolutamide treatment in addition to radical prostatectomy, in men affected by prostate cancer with specific high-risk characteristics. It investigates whether this hormonal treatment can lower the rates of noncurable recurrences, maintaining a favourable tolerability profile.