Johnson & Johnson PROTEUS Phase 3: Perioperative ERLEADA reduces risk of metastasis or death by 20%
- PROTEUS Phase 3 randomized trial (≈2,109 patients) tested perioperative apalutamide (240 mg once daily) plus ADT given 6 months before and 6 months after radical prostatectomy versus ADT alone.
- Dual primary endpoints met: pathologic complete response/minimal residual disease 8.9% vs 1.0% (OR 10.17) and metastasis‑free survival improved with a 20% reduction in risk of metastasis or death (HR 0.80) at median follow‑up of 61.7 months.
- Time to subsequent therapy extended to 74.2 months with apalutamide plus ADT versus 41.5 months with ADT alone (HR 0.65), with additional benefits in event‑free survival and time to distant metastasis.
- Safety aligned with known profile: grade 3–4 adverse events in 39.6% vs 31.0%, discontinuations due to AEs 7.4% vs 2.7%, and common AEs included hot flush, urinary incontinence and erectile dysfunction.
Study design
PROTEUS was a randomized, double‑blind Phase 3 trial (≈2,109 patients) in high‑risk localized or locally advanced prostate cancer comparing perioperative apalutamide (240 mg once daily) plus androgen deprivation therapy (6 months before and 6 months after radical prostatectomy) versus ADT alone; dual primary endpoints were pathologic complete response/minimal residual disease (pCR/MRD) and metastasis‑free survival (MFS), assessed by blinded central review, with median follow‑up 61.7 months.
Primary efficacy
pCR/MRD occurred in 8.9% versus 1.0% (OR 10.17; p<0.0001); apalutamide+ADT reduced risk of metastasis or death by 20% (HR 0.80; 95% CI 0.67–0.96; p=0.02) with five‑year MFS rates of 78.2% versus 73.5% and similar investigator‑assessed results (HR 0.74; p=0.0004).
Secondary outcomes
Time to subsequent therapy was extended to 74.2 months versus 41.5 months (HR 0.65); event‑free survival improved (HR 0.71), time to distant metastasis improved (HR 0.68), and residual cancer burden MRD rates favored the combination (30.6% vs 11.7%; OR 3.36).
Safety and regulatory status
Safety profile aligned with known apalutamide effects: common adverse events included hot flush (63.4%), urinary incontinence (50.2%) and erectile dysfunction (41.6%); grade 3–4 events occurred in 39.6% versus 31.0%, discontinuations for AEs 7.4% versus 2.7%, and most patients recovered testosterone within ~8.1 months; apalutamide plus ADT is not yet approved for this perioperative setting and further analyses are ongoing.
Source: J&J
