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Phosphate Kinetic Modeling 2 (PKM2)

This study has been completed.
Sponsor:
Collaborator:
Renal Research Institute
Information provided by (Responsible Party):
Fresenius Medical Care North America
ClinicalTrials.gov Identifier:
NCT01252771
First received: December 1, 2010
Last updated: August 14, 2014
Last verified: June 2011
  Purpose

The study aims to investigate the concept of computer based Phosphate Kinetic Modeling (PKM) in the hemodialysis patient population. This computerized algorithm model was developed as a tool to aid physicians in controlling a hemodialysis patient's phosphate level. Once a subject consents to participate in the study, the subject's dietary phosphate intake will be estimated by the modeling program and the appropriate dose of the phosphate binder calcium acetate (PhosLo) will be recommended accordingly. If necessary, the Ca++ concentration of the dialysate will be changed to remove any excess calcium absorbed as the result of an increase in the PhosLo prescription to control phosphorus.


Condition Intervention Phase
Hyperphosphatemia
ESRD
Other: PKM Algorithm
Phase 4

Study Type: Interventional
Study Design: Endpoint Classification: Efficacy Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Phosphate Kinetic Modeling 2

Resource links provided by NLM:


Further study details as provided by Fresenius Medical Care North America:

Primary Outcome Measures:
  • change in serum phosphorus [ Time Frame: 6 months ] [ Designated as safety issue: No ]
    The primary outcome variable is the change in serum phosphorus between a baseline period and the latest value of the intervention period.


Enrollment: 81
Study Start Date: September 2010
Study Completion Date: December 2011
Primary Completion Date: September 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: PKM report and algorithm
Phosphate kinetic modeling was performed and displayed in graphical form laboratory results and an estimated phophorus protein ratio
Other: PKM Algorithm

The subject's serum calcium and phosphorus values will be input into PKM in order to determine the required PhosLo prescription. The prescription is determined as the number of gelcaps per day that must be taken by the subject.

If PKM determines the number of PhosLo gelcaps per day to be greater than or equal to the subject's current prescription, then PKM will calculate the current Ca++ and phosphate balance. Furthermore, the PKM algorithm will determine the additional number of PhosLo gelcaps needed to achieve neutral phosphate (P) balance with serum P reduced to 5.5 mg/dL.

The PKM algorithm also calculates the total P intake between dialyses and along with ePCR also calculates a Phosphorus/Protein Ratio (PPR). This ratio ranges from 8 to 14 in dialysis patients following a renal diet.


Detailed Description:

PKM consists of a set of validated and computerized algorithms to perform the following steps:

  1. Calculate calcium (Ca) and phosphorus (P) intake and absorption in individual patients as a function of the prescribed doses of Vitamin D analogues, protein catabolic rate (PCR) and dietary and binder Ca intakes.
  2. Calculate P removal between dialyses by P binders and P and Ca removal during dialysis from kinetic analysis of total P and Ca transport during dialysis based on dialyzer P and Ca transport coefficients and the levels of dialysate Ca and serum Ca and P.
  3. Thus from analysis of intake, absorption and removal the program can calculate net Ca and P balance in modeled patients.
  4. Calculate the daily dose of phosphate binder (PhosLo) required to reduce the serum P to normal in patients with hyperphosphatemia.
  5. Calculate the dialysate Ca required to achieve zero calcium balance over complete dialysis cycles - the interdialytic interval and immediately succeeding dialytic interval.
  6. The program also computes a Phosphorus-Protein ratio (PPR, the total P removed divided by PCR, mg/gm/day) which provides a quantitative index of compliance with prescribed dietary P restriction and/or the prescribed dose of binders. It is hoped that this information will be valuable to guide semi-quantitative evaluations of diet P and binder intakes in patients difficult to manage. Study subjects will bring their PhosLo pill bottles to treatments weekly. At this time the subject's dietitian will determine and record the remaining pills. The comparison of pills taken versus pilled prescribed will be performed with any data available. While weekly counts are desirable for providing more information about the consistency of a patient's compliance, a minimum of monthly counts will be sufficient. This will be done to validate the PPR range needed to accurately identify compliance with PhosLo regimen. Patients will also be instructed to bring all empty PhosLo bottles to site dietitian. The site dietitian will record pill count data in a form for each patient. The updated version of the PKM algorithm also includes computation of the dose of vitamin D analogues and cinacalcet (Sensipar). This modification of the PKM algorithm may help to better achieve neutral calcium balance, because the intestinal calcium absorption heavily depends on vitamin D levels. The computation of cinacalcet aids the control of parathyroid hormone (PTH) levels within the target range.
  Eligibility

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  1. Subject is capable of giving informed consent.
  2. Age > 18 years
  3. Thrice weekly hemodialysis with a dialysate Ca++ concentration (CdiCa) of 2.0, 2.25 or 2.5 mEq/L
  4. Stable CdiCa of either 2.0, 2.25 or 2.5 mEq/L for ≥ 4 weeks
  5. Dialysis vintage ≥ 3 months
  6. Three-month average P > 5.5 mg/dL AND 2 of 3 monthly average P >=5.8 mg/dL
  7. Patients currently prescribed calcium acetate (PhosLo) mono-therapy , sevelamer monotherapy, or a combination therapy of PhosLo plus sevelamer for phosphate binding with willingness of physician to switch to PhosLo monotherapy
  8. Fresenius Optiflux F 160, 180 or 200 dialyzer

Exclusion Criteria:

  1. Any laboratory abnormality, medical condition or psychiatric disorder which in the opinion of the investigator would put the subject's disease management at risk or may result in the subject being unable to comply with study requirements
  2. Known pregnancy
  3. Parathyroidectomy
  4. iPTH < 50 pg/mL
  5. Hospitalization in past 30 days
  6. Dialysate potassium prescription other than 2 or 3 mmol/L
  7. Serum Ca++ < 7.5 mg/dL
  8. Current vitamin D therapy using calcitriol
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01252771

Locations
United States, New York
Renal Research Insitutue
New York, New York, United States, 10128
Sponsors and Collaborators
Fresenius Medical Care North America
Renal Research Institute
Investigators
Principal Investigator: Peter Kotanko, MD Renal Research Institute
  More Information

No publications provided

Responsible Party: Fresenius Medical Care North America
ClinicalTrials.gov Identifier: NCT01252771     History of Changes
Other Study ID Numbers: 10-188
Study First Received: December 1, 2010
Last Updated: August 14, 2014
Health Authority: United States: Institutional Review Board

Keywords provided by Fresenius Medical Care North America:
phosphorus
dialysis
PhosLo

Additional relevant MeSH terms:
Hyperphosphatemia
Metabolic Diseases
Phosphorus Metabolism Disorders

ClinicalTrials.gov processed this record on November 20, 2014