Nicotinamide Versus Sevelamer Hydrochloride on Phosphatemia Control on Chronic Hemodialysed Patients

The comparison between nicotinamide and sevelamer aims to demonstrate, in chronic hemodialysed patients, the non-inferiority of nicotinamide in terms of control of the phosphatemia. Secondary objectives is to compare the two treatments in terms of efficiency in other biological parameters, vascular calcification and bone mass loss and on the clinical and biological tolerance and finally to explore the roles of metabolites of nicotinamide.

This is a multicenter randomized open study with 2 treatment arms (nicotinamide / Sevelamer).

Laboratories who will dose biochemical parameters and PTH, ignore which treatment is received by patients.

The team which will measure bone density and the radiologist or rheumatologist who will appreciate centrally calcification and deformity of the vertebrae, ignore which treatment is received by patients.

Therefore it's a Randomized Prospective Blinded Outcome Endpoint.

Pre-recruitment period (3 to 6 months) with basic medication

* Repletion of vitamin D (p 25 OHD between 30 and 50 ng / ml) (if required by supplementation Dedrogyl weekly by the dialysis nurse)
* Bath dialysis to 1.50 mmol / l calcium (1.75 mmol / l if hemodiafiltration), 32 mmol bicarbonate and 0.5 mmol / l magnesium - Support to provide a dietary protein intake with 1.2 g / kg / d and assessment of contributions of Ca and PO4
* Use of CaCO3 taken with meals rich in phosphorus (morning, noon and evening) without
* In case of hyperkalemia, Calcium Sorbisterit® will preferably be used instead of KAYEXALATE®. This process exposes the worsening effect of hyperphosphatemia increasing calcium malabsorption and therefore the negative calcium balance in renal failure.
* Statin therapy, fibrate or ezetimibe if necessary, but with stable dose

This treatment will be monitored on the following parameters:

* Biochemical weekly Predialytic (midweek): creatinine, urea, PO4, Ca, protein, Na, K, bicarbonate, glucose, uric acid
* Additional monthly balance: PTH intact, Mg, albumin, CRP
* Each 4 months update: lipid profile (fasting or not, but always at the same time, 25 OH D, complete blood count (CBC), AST-ALT, total alkaline phosphatase, gamma-GT, PKC, glycated hemoglobin (HbA1C) )

Recruitment (180 patients):

* Obtaining informed consent
* Perform a bone density by DXA third of the radius (cortical bone), radius ultradistal (trabecular bone), femoral neck bone (mixed), whole body and lumbar spine profile radiography.
* Lumbar and dorsal radiography (frontal and profile) for research and vertebral measurement of aortic calcification by the Framingham score) + pelvis radiography (frontal) and 2 hands radiography (frontal) searching vascular calcification, Looser's streaks and subperiosteal resorption.
* Freezing at -80 ° C (4 tubes of 1 ml of serum)for centralized analysis:PTH, 25 OHD, CTX, PAO. All samples will be sent for laboratory analysis of Biochemistry University Hospital of Amiens at the end of the study.

For this, 10 ml of blood will be collected with a dry tube then centrifuged 15 minutes, 4000-5000 rpm at room temperature within 30 minutes after collection. Then, aliquot 1ml into 4 polypropylene tubes being careful not to take the fibrin.

* Freezing at -80 ° C in a tube of 2.5 ml of plasma to be assayed later the metabolites of nicotinamide. These samples will only be achieved if patients accept and mark the second part of the consent. The tubes are then stored in the biological resource center, CHU Amiens for further research and for an indefinite period.

The nicotinamide metabolites measured in this study will annex the Met2PY (N-methyl-2-pyridone-5-carboxamide), the Met4PY (N-methyl-4-pyridone-3-carboxamide) and NAD (nicotinamide adenine dinucleotide).

6 ml of EDTA whole blood will be collected, then centrifuged 15 minutes, 4000-5000 rpm at room temperature within 30 minutes after collection. Then, 2.5 ml aliquot in 1 polypropylene tube.

* Then a heparinized blood sample of 2.5 ml will be frozen at -80 °C for determination of nicotinamide. All samples will be sent for analysis at CERBA at the end of the study.

Randomization will be done by the minimization technic with stratification factors: center, duration of dialysis and taking lipid lowering therapy. Randomization will be performed remotely via a website.

Follow-up of one year:

* Period titration nicotinamide or sevelamer to control serum phosphorus in 4 weeks, with stable doses of CaCO3
* Increased nicotinamide 500 mg up to 4 tablets: 0-1-0, 0-1-1, 1-1-1, 1-2-1
* Increased sevelamer 800 mg up to 12 tablets: 0-2-2 ; 2-4-4 ; 4-4-4 ; 2-5-5
* Maintenance period of 5 months with assessment of maintenance doses of Renagel (sevelamer) or Nicobion (nicotinamide) or during the last 3 months.
* After these 6 months:
* Freezing -80 ° C, 4 tubes of 1 ml of serum centralized reviews PTH, 25 OHD, CTX, PAO (as mentioned above).
* Freezing -80 ° C in a tube of 2.5 ml of plasma to be assayed later the metabolites of nicotinamide (as mentioned above).
* Freezing -80 ° C with a heparinized blood sample of 2.5 ml for determination of nicotinamide (as mentioned above).
* Second randomization via a website, patients with intact PTH\> 300 pg / ml after 6 months of Nicobion ® and Renagel ®. Randomization 75-150 pg / ml or 150-300 mg / ml will be made by the minimization technic with stratification factors: the center and the type of Hypophosphatemia PTH will be reduced by introducing cinacalcet ® by increments of 30 mg every 3 weeks to 180 mg / day (given with meals 24 hours before the next dialysis). Increase of Cinacalcet ® will be stopped when PTH is \<250 pg / ml for arm 150-300pg/ml or \<125 per arm 75-150 pg / ml.

Once corrected calcemia \<2.25 mmol / l, doses of CaCO3 will be increased; if the maximum tolerable of CaCO3 on the tract map does not prevent hypocalcemia (\<2.10 mmol / l), the calcium bath will be increased to 1.75 mmol / l CaCO3 decreased and, if necessary adjustment of nicotinamide / Sevelamer to maintain PO4 between 1.30 and 1.60 mmol / l.

* During the first 6 months of administration of sevelamer, weekly, monthly and quarterly reports will be done. Regarding PTH assay will be performed, every 3 weeks during the titration of cinacalcet.
* A lumbar and dorsal radiography (frontal and profile), a pelvis radiography (face) and 2 hands radiography (front) will be conducted at the end of follow-up period.
* Bone densitometry will be performed at the end of the study (same camera - same site).
* Case report form: tolerance, serious adverse events, compliance, cardiovascular events (myocardial infarction, PAO, stroke, arteritis, vascular intervention),deaths and fractures during the follow-up study.
* Freezing -80 ° C to 4 tubes of 1 ml of serum centralized reviews PTH, 25 OHD, CTX, PAO at the end of the study (as mentioned above).
* Freezing -80 ° C in a tube of 2.5 ml of plasma to be assayed later the metabolites of nicotinamide at the end of the study (as mentioned above).
* Freezing at -80 ° C with a heparinized blood sample of 2.5 ml for determination of nicotinamide at the end of the study (as mentioned above).

Analytical Methodology

Eligibility Criteria:
Inclusion Criteria:

* Women or men over 18 years
* Chronic hemodialysis (since more than 3 months)
* Hyperphosphatemia controlled with only CaCO3
* PO4 \> 1,60 mmol/l, PCa \< 2,37 mmol/l
* patient able to understand and sign informed consent form

Exclusion Criteria:

* PTH \< 60 ou \> 800 pg/ml (PTX)
* Aluminium intoxication (aluminium level in blood \> 0,5 µmol/l)
* Score of aortic calcifications ≥ 20 (max 24)
* Characterized intolerance with Renagel and/or Nicobion
* Pregnant woman
* Autoimmune disease
* Patient known to have a bad drug compliance
* Blood tests abnormality (thrombopenia \<150 000, serum albumin \<30g)
* Hepatic tests abnormality
* Transplant probably within 6 months
* Patient who will need transplantation within 6 month
* Patients receiving chemotherapy
* Patients having a loss of dry weight of 3 kg in 3 months or 6 kg in 6 months.