PURPOSE: Denosumab, an anti-RANK ligand monoclonal antibody, significantly increases bone metastasis-free survival (BMFS; hazard ratio [HR], 0.85; P = .028) and delays time to first bone metastasis in men with nonmetastatic castration-resistant prostate cancer (CRPC) and baseline prostate-specific antigen (PSA) ≥ 8.0 ng/mL and/or PSA doubling time (PSADT) ≤ 10.0 months.
To identify men at greatest risk for bone metastasis or death, we evaluated relationships between PSA and PSADT with BMFS in the placebo group and the efficacy and safety of denosumab in men with PSADT ≤ 10, ≤ 6, and ≤ 4 months.
PATIENTS AND METHODS: A total of 1,432 men with nonmetastatic CRPC were randomly assigned 1:1 to monthly subcutaneous denosumab 120 mg or placebo. Enrollment began February 2006; primary analysis cutoff was July 2010, when approximately 660 men were anticipated to have developed bone metastases or died.
RESULTS: In the placebo group, shorter BMFS was observed as PSADT decreased below 8 months. In analyses by shorter baseline PSADT, denosumab consistently increased BMFS by a median of 6.0, 7.2, and 7.5 months among men with PSADT ≤ 10 (HR, 0.84; P = .042), ≤ 6 (HR, 0.77; P = .006), and ≤ 4 months (HR, 0.71; P = .004), respectively. Denosumab also consistently increased time to bone metastasis by PSADT subset. No difference in survival was observed between treatment groups for the overall study population or PSADT subsets.
CONCLUSION: Patients with shorter PSADT are at greater risk for bone metastasis or death. Denosumab consistently improves BMFS in men with shorter PSADT and seems to have the greatest treatment effects in men at high risk for progression.
Smith MR, Saad F, Oudard S, Shore N, Fizazi K, Sieber P, Tombal B, Damiao R, Marx G, Miller K, Van Veldhuizen P, Morote J, Ye Z, Dansey R, Goessl C. Are you the author?
Massachusetts General Hospital Cancer Center, Boston, MA; University of Montreal Hospital Center, Montreal, Quebec, Canada; Georges Pompidou Hospital, Paris; Institut Gustave Roussy, University of Paris Sud, Villejuif, France; Carolina Urological Research Center, Myrtle Beach, SC; Urological Associates of Lancaster, Lancaster, PA; Université Catholique de Louvain Cliniques Universitaires Saint Luc, Bruxelles, Belgium; Hospital Universitario Pedro Ernesto, Rio de Janeiro, Brazil; Sydney Haematology and Oncology Clinic, University of Sydney, Wahroonga, New South Wales, Australia; Charité Berlin, Berlin, Germany; Kansas City Veterans Affairs Medical Center, Kansas City, MO; Hospital Vall d'Hebron, Barcelona, Spain; Amgen, Thousand Oaks, CA.
Reference: J Clin Oncol. 2013 Sep 16. Epub ahead of print.