title: Effects of denosumab in patients with bone metastases with and without previous bisphosphonate exposure.
abstract: Bone metastases place patients at increased risk of skeletal-related events (SREs), including pathologic fractures, spinal cord compression, severe pain requiring radiotherapy or surgery, and hypercalcemia, because of increased osteoclast-mediated bone resorption. Denosumab, a fully human monoclonal antibody, decreases bone resorption by inhibiting RANKL, which mediates osteoclast activity. We compared the effects of denosumab in two phase 2 studies in patients with bone metastases naive to intravenous bisphosphonate therapy (IV BP; n = 255) and those with elevated levels of the bone resorption marker urinary N-telopeptide (uNTX) despite ongoing IV BP treatment (n = 111). Patients were randomized to receive IV BP every 4 weeks or subcutaneous denosumab every 4 weeks (30/120/180 mg) or every 12 weeks (60/180 mg). Patients treated with denosumab experienced a rapid and sustained reduction in bone turnover regardless of prior IV BP exposure. After 25 weeks, the median uNTX reduction was 75% (IV BP-naive) and 80% (prior IV BP) after denosumab treatment and 71% (IV BP-naive) and 56% (prior IV BP) in the IV BP arms. Denosumab patients with prior IV BP exposure had marked suppression of the osteoclast marker TRAP-5b (median reduction: denosumab 73%, IV BP 11%). SRE incidence was low across both studies. In patients previously treated with BPs, the rate of first on-study SRE was lower in the denosumab groups (8%) than the IV BP group (17%). Denosumab appeared to be well tolerated in both studies. Denosumab suppresses bone resorption markers independently of prior BP treatment, even in patients who appear to respond poorly to BPs.
authors: CHU Brugmann, Université Libre de Bruxelles, Brussels, Belgium. Jean-jacques.body@chu-brugmann.be
authors: Jean-Jacques
authors: JJ
authors: Body
authors: Allan
authors: A
authors: Lipton
authors: Julie
authors: J
authors: Gralow
authors: Guenther G
authors: GG
authors: Steger
authors: Guozhi
authors: G
authors: Gao
authors: Howard
authors: H
authors: Yeh
authors: Karim
authors: K
authors: Fizazi
mesh_terms: D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D015415:Biomarkers / Q000097:blood / Q000378:metabolism; D050071:Bone Density Conservation Agents / Q000627:therapeutic use; D001859:Bone Neoplasms / Q000188:drug therapy* / Q000503:physiopathology / Q000556:secondary; D001842:Bone and Bones / Q000378:metabolism*; D000069448:Denosumab; D004164:Diphosphonates / Q000008:administration & dosage / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007279:Injections, Subcutaneous; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000188:drug therapy* / Q000503:physiopathology; D053245:RANK Ligand / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D015415:Biomarkers; D050071:Bone Density Conservation Agents; D004164:Diphosphonates; D053245:RANK Ligand; D000069448:Denosumab