Modulation of NTX in patients with metastatic CRPC after treatment with novel therapies. (A) Percentage change in uNTX during weeks 1 to 25 in patients treated with denosumab or zoledronic acid, demonstrating rapid denosumab-induced suppression of bone resorption (reprinted from Fizazi et al. [97], Copyright 2009, with permission from Elsevier). (B) Waterfall plot of maximal percentage change in uNTX from baseline in patients treated with 70 or 100mg of dasatinib twice daily. Of 41 patients, 33 (80%) had a decrease in uNTX while on study (reproduced and adapted from Yu et al. [90], with permission from the American Association for Cancer Research). (C) Percentage change in uNTX during weeks 1 to 12 in patients treated with atrasentan or atrasentan plus zoledronic acid. Mean serum NTX increased by 32.4% ± 14.5% with atrasentan and decreased by 34.4% ± 6.9% in the combination group (P < .001; reproduced and adapted from Michaelson et al. [87], with permission from John Wiley and Sons).