title: Paricalcitol versus cinacalcet plus low-dose vitamin D for the treatment of secondary hyperparathyroidism in patients receiving haemodialysis: study design and baseline characteristics of the IMPACT SHPT study.
abstract: BACKGROUND
  Paricalcitol and cinacalcet are common therapies for patients on haemodialysis with secondary hyperparathyroidism (SHPT). We conducted a multi-centre study in 12 countries to compare the safety and efficacy of paricalcitol and cinacalcet for the treatment of SHPT.
  
  
  METHODS
  Patients aged ≥18 years with Stage 5 chronic kidney disease receiving maintenance haemodialysis and with intact parathyroid hormone (iPTH) 300-800 pg/mL, calcium 8.4-10.0 mg/dL (2.09-2.49 mmol/L) and phosphorus ≤6.5 mg/dL (2.09 mmol/L) were randomized within two strata defined by the mode of paricalcitol administration to treatment with paricalcitol- (intra-venous, US and Russian sites, IV stratum; oral, non-US and non-Russian sites, oral stratum) or cinacalcet-centred therapy. The primary endpoint is the proportion of patients in each treatment group who achieve a mean iPTH value of 150-300 pg/mL during Weeks 21-28 of treatment. Assuming efficacy response rates of 36 and 66% for cinacalcet and paricalcitol, respectively, and a 20% discontinuation rate, 124 subjects in each stratum were estimated to provide 81% power to detect a 30% absolute difference in the primary endpoint.
  
  
  RESULTS
  Of 746 patients screened, 272 (mean age, 63 years; mean iPTH, 509 pg/mL) were randomized. Mean duration of haemodialysis at baseline was 3.7 years. Comorbidities included hypertension (90.4%), Type 2 diabetes (40.4%), congestive heart failure (17.3%), coronary artery disease (34.6%) and gastrointestinal disorders (75%).
  
  
  CONCLUSIONS
  The study participants are representative of a multinational cohort of patients on haemodialysis with elevated iPTH. The study results will provide valuable information on the best available treatment of SHPT in patients on haemodialysis.
authors.affiliation: Division of Nephrology, Klinikum Coburg, Coburg, Germany. markus.ketteler@klinikum-coburg.de
authors.forename: Markus
authors.initials: M
authors.lastname: Ketteler
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Martin
authors.forename: Mario
authors.initials: M
authors.lastname: Cozzolino
authors.forename: David
authors.initials: D
authors.lastname: Goldsmith
authors.forename: Amit
authors.initials: A
authors.lastname: Sharma
authors.forename: Samina
authors.initials: S
authors.lastname: Khan
authors.forename: Emily
authors.initials: E
authors.lastname: Dumas
authors.forename: Michael
authors.initials: M
authors.lastname: Amdahl
authors.forename: Steven
authors.initials: S
authors.lastname: Marx
authors.forename: Paul
authors.initials: P
authors.lastname: Audhya
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D050071:Bone Density Conservation Agents / Q000009:adverse effects / Q000627:therapeutic use; D057966:Calcimimetic Agents / Q000009:adverse effects / Q000627:therapeutic use; D000069449:Cinacalcet; D015331:Cohort Studies; D019468:Disease Management; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D004872:Ergocalciferols / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000188:drug therapy*; D007674:Kidney Diseases / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009281:Naphthalenes / Q000009:adverse effects / Q000627:therapeutic use*; D017410:Practice Guidelines as Topic; D006435:Renal Dialysis; D016896:Treatment Outcome; D014807:Vitamin D / Q000627:therapeutic use*
chemical_list: D050071:Bone Density Conservation Agents; D057966:Calcimimetic Agents; D004872:Ergocalciferols; D009281:Naphthalenes; D014807:Vitamin D; C084656:paricalcitol; D000069449:Cinacalcet