title: Real-world dose-relativity, tablet burden, and cost comparison of conversion between sevelamer hydrochloride/carbonate and lanthanum carbonate monotherapies.
abstract: OBJECTIVE
  Sevelamer hydrochloride/carbonate (SH/C) and lanthanum carbonate (LC) are noncalcium-based phosphate binders used for the management of hyperphosphatemia in patients with end-stage renal disease (ESRD). The objectives of this study were to examine the dose-relativity, tablet burden, and cost difference of bidirectional conversion between SH/C and LC monotherapy in a large cohort of real-world patients with ESRD.
  
  
  METHODS
  This retrospective cohort study included three 30-day preconversion periods (days -90 to -61, -60 to -31, and -30 to -1) followed by three 30-day postconversion periods (days 1 to 30, 31 to 60, and 61 to 90); day 0 was the index date of conversion. The full analysis population (FAP) comprised two cohorts: SH/C to LC (S-L) converters and LC to SH/C (L-S) converters. The SH/C:LC dose-relativity ratio was assessed in the dose-relativity subset, defined as patients whose serum phosphate levels fell within a caliper range of ± 0.5 mg/dL in the final preconversion (days -30 to -1) and postconversion (days 61 to 90) periods. Tablet burden and phosphate binder costs were assessed in the FAP. Phosphate binder costs were based on average wholesale prices.
  
  
  RESULTS
  The FAP contained a total of 303 patients, comprising the S-L (128 patients) and L-S (175 patients) converter cohorts. The dose-relativity subset contained 159 patients, 72 from the S-L cohort and 87 from the L-S cohort. The overall mean SH/C:LC dose-relativity ratio was 2.27 (95% CI, 2.04 to 2.52). In SH/C dose strata >800 to 2400, >2400 to 4800, >4800 to 7200, and >7200 mg/d, overall mean dose-relativity ratios were 0.79 (95% CI, 0.57 to 1.10), 1.45 (95% CI, 1.20 to 1.75), 2.05 (95% CI, 1.75 to 2.39), and 3.24 (95% CI, 2.89 to 3.66), respectively. The overall mean tablet burden was 6.6 tablets per day lower with LC monotherapy than with SH/C monotherapy (95% CI, -7.1 to -6.0; P < 0.0001). The overall mean binder cost/patient per month was $1080.40 for SH/C compared with $1006.20 for LC, corresponding to a mean binder cost saving for LC of $74.20/patient per month (95% CI, -141.80 to -6.63; P = 0.032). SH/C >7800 mg/d was the inflection point at which conversion to LC resulted in mean cost savings. Patients requiring SH/C >7800 mg/d comprised 50% of the FAP.
  
  
  CONCLUSIONS
  Converting patients with ESRD and hyperphosphatemia from SH/C to LC monotherapy offers potential drug cost savings and a significant reduction in the daily tablet burden, without compromising the effective management of serum phosphate levels.
authors.affiliation: Shire, Wayne, Pennsylvania, United States. Electronic address: mkeith@shire.com.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Keith
authors.affiliation: DaVita Clinical Research, Minneapolis, Minnesota, United States.
authors.forename: Scott
authors.initials: S
authors.lastname: Sibbel
authors.affiliation: Shire, Wayne, Pennsylvania, United States.
authors.forename: J Brian
authors.initials: JB
authors.lastname: Copley
authors.affiliation: Spica Consultants, Marlborough, United Kingdom.
authors.forename: Rosamund J
authors.initials: RJ
authors.lastname: Wilson
authors.affiliation: DaVita Clinical Research, Minneapolis, Minnesota, United States.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Brunelli
mesh_terms: D000328:Adult; D003365:Costs and Cost Analysis; D005260:Female; D006801:Humans; D054559:Hyperphosphatemia / Q000188:drug therapy* / Q000191:economics*; D007676:Kidney Failure, Chronic / Q000188:drug therapy* / Q000191:economics*; D007811:Lanthanum / Q000008:administration & dosage / Q000191:economics / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D000069603:Sevelamer / Q000008:administration & dosage / Q000191:economics / Q000627:therapeutic use; D013607:Tablets
chemical_list: D013607:Tablets; C119467:lanthanum carbonate; D007811:Lanthanum; D000069603:Sevelamer
keywords: cost-effectiveness; dose-relativity; end-stage renal disease; hyperphosphatemia; lanthanum carbonate; phosphate binder; sevelamer hydrochloride; tablet burden