OBJECTIVES: To examine the pharmacy budget impact (PBI) of extending reimbursement of non-calcium lanthanum carbonate (LC) to treatment of hyperphosphatemia (serum phosphorus>1.78mmol/L) in patients with chronic kidney disease pre-dialysis (CKD-ND) in France and the UK over five years. METHODS: The treated prevalence of CKD-ND and hyperphosphatemia, and the use of pharmacologic therapies, were estimated using published literature and EU nephrologist surveys.  Drug costs were estimated from published sources.  Market share changes were estimated from market research.  Base-case analyses assumed complete medication compliance.  Annual PBI was calculated as the difference in total drug costs between scenarios with and without the reimbursement extension for LC.  Alternate scenarios and deterministic sensitivity analyses were also estimated. RESULTS: A small percentage of CKD-ND patients, 14,500 (7%) and 64,600 (14.6%), are estimated as hyperphosphatemic in France and the UK, respectively.  Of these patients, 81% in France versus 30% in the UK are estimated to receive phosphate binder therapy. CKD-ND market share for LC is estimated at 12% in France and 1-2% in the UK. The label extension, adding hyperphosphatemic CKD-ND patients, is estimated to increase LC use primarily at the expense of calcium-based phosphate binders. The annual PBI from the label extension is estimated to grow over Years 1-5 from 0 to €1.1M in France; and to be