Effect of zoledronic acid (Z) on pain in prostate cancer patients with bone metastases based on performance status

Abstract

14544 Background: Z has demonstrated efficacy in reducing, preventing, delaying the occurrence of an SRE (Skeletal Related Event) including pathologic fractures, severe bone pain requiring radiation therapy, spinal cord compression, surgery to bone and hypercalcemia of malignancy which could lead to a loss of independence. Effects of Z on pain were analyzed in a subgroup of patients based on performance status. Methods: Subjects were randomised to Z 4mg (n = 201) or placebo (n = 201). The short form of the Brief Pain Inventory (BPI) was administered at baseline (visit 2), and visits 3 (weeks 3–4), 4 (weeks 6–8), and then every second visit (every 6 weeks) until study end. Changes in BPI individual item scores and the Pain severity and Pain Interference scale scores were compared between Z and placebo groups. Post baseline missing data were replaced by Last Observation carried forward (LOCF). Changes in scores were examined in the subgroup of patients with ECOG performance status scores of ≥ 1. Results: For patients ECOG score of ≥ 1 at baseline (n = 227), Z was superior to placebo in the BPI items ‘pain at its worst’, ‘pain at its least’, ‘pain on average’, and the Pain Severity scale at visit 4 (weeks 6–8) and visit 6 (week 12) (p < 0.05). At visit 8 (weeks 18–20) Z was superior to placebo on the ‘pain on average’ item and Pain Severity scale (p < 0.05). For visit 12 (weeks 30–32) and for LOCF Z was superior to placebo for ‘pain at its worst’, ‘pain on average’ and Pain Severity (p < 0.05 for all). For the ‘pain right now’ item there were statistically significant differences at visits 4, 6, 12 and LOCF (p < 0.05). In addition, at visit 6 (week 12), Z was superior to placebo for changes in items assessing interference with: sleep, general activities, mood, walking and enjoyment of life (p < 0.05). Z was also superior to placebo for ‘interference with general activities’ at visits 12 (weeks 30–32), 16 (weeks 42–44) and LOCF (p < 0.05). Conclusion: Results suggest Z provides significant benefit in pain reduction and Z may have an impact on patients’ daily activities which may lead to a preservation of patients’ functionality. [Table: see text]