Efficacy of Lanthanum Carbonate in Calciphylaxis

Calciphylaxis or calcific uremic arteriolopathy is an infrequently occurring although debilitating vasculopathy seen primarily in patients with end stage renal disease (ESRD) which almost always affects the skin. It has a prevalence rate ~4 % in long term hemodialysis patients, with 1-year survival of 45% and an 8-fold risk of death as compared to the general dialysis population. (Surgery 1997;122:1083-1089, Kidney Int 2001;60:324-332). Despite being described in the literature for over 100 years, there has been no proven effective therapy. Lanthanum carbonate (FOSRENOL®) is a potent non-aluminum, non-calcium phosphate binder that was approved for use to reduce serum phosphate levels in patients with end stage renal disease. Since the proposed etiologic mechanism of injury and vascular calcification of calciphylaxis is predominantly hyperphosphatemia, elevated serum PTH, and hypercalcemia, FOSRENOL® would be an ideal pharmacologic agent to utilize in this extremely enigmatic disease (Dermatol Clin. 2008 Oct;26(4):557-68). Furthermore, a recent case report demonstrated a significant improvement in laboratory parameters and calciphylaxis skin lesions with the use of FOSRENOL® (WMJ. 2008 Nov;107(7):335-8). The primary hypothesis is that since calciphylaxis represents the ultimate sequelae of metastatic vascular calcification predominantly involving hyperphosphatemia, elevated serum PTH, and hypercalcemia, FOSRENOL® will be efficacious in its treatment.