Effect of denosumab versus zoledronic acid in patients with castrate-resistant prostate cancer and bone metastases: Subgroup analyses by prior SRE and baseline pain.

• DOI: 10.1200/jco.2011.29.15_suppl.4533
• Publication Date: 2017-02-23T18:58:03Z
• Authors: N. D. Shore; M. R. Smith; M. Jievaltas; K. Fizazi; R. Damião; J. Chin; K. Miller; J. P. Maroto; Y. Qian; A. Feng; K. Chung; C. D. Goessl
• Keywords: Denosumab; Zoledronic Acid; Clinical endpoint; Brief Pain Inventory; Bone pain; Spinal cord compression

4533 Background: Bone metastases from castrate-resistant prostate cancer (CRPC) are associated with osteoclast-mediated bone destruction and skeletal-related events (SREs). Denosumab is a fully human monoclonal antibody against RANKL, key mediator of osteoclast formation, function, survival. Previous results phase III trial showed denosumab was superior to zoledronic acid (ZA) in delaying or preventing SREs (pathologic fracture, radiation surgery bone, spinal cord compression) patients CRPC. This analysis assesses the effect vs ZA treatment among earlier stage CRPC - those no prior SRE no/mild pain at baseline. Methods: Patients ≥1 metastasis IV bisphosphonate use were randomized receive either SC 120 mg + placebo 4 (adjusted for creatinine clearance) every weeks. also instructed take calcium vitamin D supplements. Time 1st on-study (primary endpoint) time subsequent (multiple event analysis) evaluated pain. The Brief Pain Inventory – Short Form (BPI) used assess worst scores A score 0 on BPI indicates mild Results: Of 1901 enrolled (n = 950 denosumab; n 951 ZA), 1438 subgroup 1045 (BPI 4) As compared ZA, significantly delayed overall population (HR 0.82 [0.71, 0.95]; P 0.008), as well both subgroups disease: 0.80 [0.67, 0.011) baseline 0.77 [0.63, 0.014). Similar noted (P ≤ 0.007 all groups). Conclusions: reduced SREs.