Aims: To describe the effects of two consecutive intravenous infusions of aminohexane bisphosphonate (Neridronate) in patients with active Paget's disease of bone.
Methods: The study population included 83 patients, aged 41 to 85 years, randomized to 4 cumulative doses of Neridronate (25, 50, 100, 200 mg) given over 2 days, with a follow up of 180 days. The baseline serum alkaline phosphatase activity was at least 10% above the upper limit of the laboratory range. The response to treatment was assessed by changes in the serum total alkaline phosphatase (primary end point of the study), bone alkaline phosphatase and N-telopeptide urinary excretion.
Results: All Neridronate doses significantly suppressed the biochemical indices of disease activity. The nadir of total alkaline phosphatase levels ranged from -16 % to -57.5% of pretreatment values in the four groups, with a dose-response relationship that was apparent even between the two highest doses. The proportion of patients still maintaining a partial response (decreases in serum total alkaline phosphatase >25%) at the 6 month follow-up was also related to the dose: 98%, 67%, 57%, 21% in the patients given 200, 100, 50, 25 mg respectively. The proportion of responders in terms of bone alkaline phosphatase and N-telopeptide excretion changes was similar. Bone pain attributed to Paget's disease was significantly reduced. A typical acute phase reaction (fever and/or arthromyalgia) occurred in 16 out of 83 patients.
Conclusions: We conclude that all of the Neridronate doses tested here were well tolerated and effective in decreasing, in a dose-related manner the bone turnover parameters of Paget's disease. The highest dose (200 mg) resulted in the normalization of the markers of disease activity in more than 60% of the patients.