In summary, the clinical efficacy studies provide clear evidence that treatment with oral
alendronate markedly suppresses bone turnover and produces clinical improvement in pagetic patients. Serum
alkaline phosphatase was greatly decreased by treatment, and the response to
alendronate was superior to that observed for currently available
therapies such as
etidronate and
calcitonin, which usually reduce
alkaline phosphatase, on average, by 40%-50%.
Alendronate also markedly reduced urinary resorption markers and induced radiologic improvement of pagetic
osteolysis. A majority of
alendronate-treated patients normalized their serum
alkaline phosphatase by month 6. This observation is likely to be relevant to the duration of response to treatment, as previous studies have shown that the degree of suppression of
alkaline phosphatase after antiresorptive treatment correlates with the duration of remission. Therefore, patients who responded to treatment with
alendronate, especially those who normalized their
alkaline phosphatase levels, are likely to maintain the biochemical remission for several years. Indeed, preliminary unpublished data seem to indicate that
alendronate is capable of producing long-term biochemical remission in the majority of patients. In addition to its efficacy, the safety and tolerability profile of
alendronate 40 mg/day was very favorable and, overall, comparable to that of placebo.