Denosumab significantly delayed the time to first on-study HCM , representing a 37 % reduction in the hazard ratio ( HR ) compared with zoledronic acid ( HR , 0.63 ; 95 % confidence interval ( CI ) : 0.41-0 .98 ; P = 0.042 ) and reduced the risk of developing recurrent HCM ( time to first and subsequent on-study HCM ) by 52 % ( rate ratio , 0.48 ; 95 % CI : 0.29-0 .81 ; P = 0.006 ) .