We chose a very serious, acute model of renal insufficiency to examine the efficacy of the single IV dose of AMG 416 vs oral cinacalcet in the presence of elevated PTH and serum creatinine. Moreover, we ex amined the activity of AMG 416 in a model of chronic uremia, in rats under 56 nephrectomy so as to com pare the efficacy of AMG 416 and cinacalcet in excess of repeated dosing all through a 28 day administration time period. Solutions Test compounds AMG 416 was ready as described previously. Cinacalcet was ready from commercial tablets like a suspension in typical saline. Evaluation of AMG 416 in one Kidney one Clip rat model of acute renal dysfunction The 1K1C model was based mostly to the original model devel oped by Goldblatt. Male Sprague Dawley rats had been bought from Charles River Laborator ies, pre cannulated in the jugular and femoral veins for blood sampling and dosing, respectively.

The examine protocol was accredited by the Institutional description Animal Care and Use Committee of KAI Pharmaceuti cals, Inc. Basic anesthesia was induced and maintained by intraperitoneal injection of sodium pentobarbital. The two kidneys were exposed via laparot omy. The appropriate kidney was eliminated following ligation in the proper renal pedicle and ureter. A microvascular clip was utilized to the left renal artery for 45 min and after that re moved. Ischemia was assessed by shade alter during the af fected kidney. The abdominal incision was then closed plus the animal was allowed to recover for about 48 hrs just before dosing. Animals have been treated with both AMG 416, saline or cinacalcet. Ani mals were provided free access to food and water.

Blood samples had been taken through the kinase inhibitorVX-765 jugular cannula under anesthesia. Samples were taken at the indicated occasions and processed straight away for plasma. Evaluation of AMG 416 in 56 Nephrectomized Rats A four week, repeat dose research was performed in 56 nephrectomized male SD rats at CRL. The protocol was accredited by the IACUC of CRL. Ani mals weighed 300 g in the time on the very first surgery. During the to start with operation, 23 of one particular kidney was surgically re moved. After a a single week recovery, another kidney was eliminated, leaving the rat with 16 of its unique renal capability. Catheters were implanted in just about every jugular vein through the 2nd operation for drug administration and blood sampling. Animals were permitted to recover for 9 10 days following surgical procedure prior to dosing.

Thirty 6 animals were included during the study. Animals had been randomized to study drug based on serum creatinine and plasma PTH collected on Days three and two. Twelve animals per group received everyday adminis tration of saline or AMG 416 or cinacalcet for 28 days. Blood samples have been taken for PTH and calcium analysis before dosing and at 6 and sixteen hrs post dose on Days 7, 14, 21 and 28. Animals were sacrificed on Day thirty and blood was taken for PTH examination. Because of mortality during the examine, group sizes for PTH and Ca analysis had been seven, six and 9 for saline, cinacalcet and AMG 416, respectively. Plasma and serum examination Plasma PTH levels were quantified according for the guy ufacturers protocol using rat bioactive intact PTH ELISA kits from Immutopics Global. Raw data have been analyzed with GraphPad Prism.

When suitable, 1 way ANOVA was applied to find out stat istical significance with Bonferroni submit test analysis. Serum was obtained by permitting blood samples to clot for roughly 30 60 minutes followed by centrifugation. Creatinine concentration was deter mined according to your manufacturers protocol employing the QuantiChrom kit. Serum samples were analyzed for complete calcium content material at SRI utilizing the Roche Cobas C 501 autoanalyzer. Outcomes AMG 416 suppresses PTH in animals with severely compromised renal function To mimic the pathology of renal failure along with the associated increases in PTH that happen to be observed in ESRD individuals with chronic kidney ailment, mineral and bone disorder, AMG 416 was evaluated inside a rat model of acute renal insufficiency.