Johnson & Johnson announced results from its Phase 3 PROTEUS study, showing that apalutamide combined with hormone therapy reduced the risk of metastasis or death by 20% in patients with high-risk localized or locally advanced prostate cancer. The trial enrolled 2,109 patients and met both primary endpoints.
Patients treated with apalutamide plus androgen deprivation therapy were nine times more likely to have minimal cancer remaining at surgery compared with hormone therapy alone (8.9% vs 1.0%). The combination extended the time before requiring subsequent therapy to over six years, compared to about three and a half years with hormone therapy alone.
Findings were presented at ASCO and published in The New England Journal of Medicine. At a median follow-up of 61.7 months, five-year metastasis-free survival was 78.2% for the combination vs 73.5% for hormone therapy alone. The study also showed a 29% reduction in the risk of disease recurrence or death.
Grade 3 or 4 adverse events occurred in 39.6% of patients receiving apalutamide plus hormone therapy, compared to 31.0% with hormone therapy alone. Common adverse events included hot flush, urinary incontinence, and erectile dysfunction. Discontinuation rates were 7.4% and 2.7%, respectively.
