OBJECTIVES: To evaluate the effect of patent expiry and subsequent market liberalization, with generic substitution and price decline, on CE ratios of cinacalcet in patients with ESRD on dialysis. METHODS: Cinacalcet plus standard of care was compared to standard of care alone in the prevention of complications associated with uncontrolled mineral metabolism in patients with ESRD in the UK (National Health Service). Relative reductions (HRR; 95% CI) in the rates of fractures (0.46; 0.22–0.95), cardiovascular hospitalizations (0.61; 0.43–0.86), parathyroidectomy (0.07; 0.01–0.55) and all-cause mortality (0.81; 0.45–1.45), as observed in the pooled analysis of phase 3 trials in 1,184 patients were used to build a decision analysis model. CE ratios of cinacalcet (GBP0.145 per mg, 71.6mg/day) were estimated over the lifetime of a 55-year old patient with ESRD, assuming UK mortality rates and national tariffs for the diagnosis related group of each complication. Combinations of price decline and market substitution upon generic market entry were modeled to start in 2015. CE ratios (2005GBP per QALY) were calculated for ten cohorts of 55-year olds, starting in 2006. A discount rate of 3.5% was used for both costs and clinical benefits; all CE-ratios were discounted to the year 2006. RESULTS: Baseline (no patent expiry) CE ratio of cinacalcet was GBP35,600 per QALY gained. CE ratios declined over time as a function of generic discount and market share. CONCLUSIONS: CE ratios decline over time as a function of patient-expiry and subsequent market liberalization. CE calculations should account for the likely market dynamics associated with time-limited intellectual property rights. Market-adjusted CE ratios may influence funding decisions contingent upon predetermined thresholds.