es not affect the lipid lowering effects of HMG-CoA reductase inhibitors or the PTH lowering effect of calcitriol.
13 NONCLINICAL TOXICOLOGY
13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility
Carcinogenicity studies were performed in mice and rats.
In the 2-year carcinogenicity study in mice, animals were given Velphoro by diet at doses of 250, 500 or 1,000 mg/kg/day. Rare but not statistically significant neoplastic adenocarcinomas were seen in the colon of male mice at doses of 500 and 1,000 mg/kg/day. For a 60 kg person, the no-observed-adverse-effect level (NOAEL) of 250 mg/kg/day represents 5 times (on a body weight basis) the maximum recommended clinical dose of 3,000 mg/day. In addition, an increased incidence of epithelial hyperplasia was seen in the colon at all dosage levels (i.e., ≥5 times the maximum recommended clinical dose) and in the cecum at the highest dosage (equivalent to 20 times the maximum recommended clinical dose). The development of adenocarcinoma in the male mice was considered not a genotoxic effect, but the result of chronic local irritation from high amounts of intraluminal Velphoro in the GI tract.
In the 2-year rat carcinogenicity study, animals were given Velphoro by diet at doses of 40, 150 or 500 mg/kg/day. No statistically significantly increased incidences of tumors were found, but there were increased incidences in epithelial hyperplasia with or without submucosal inflammation in duodenum, cecum and colon at the dose of 500 mg/kg/day (10 times the maximum recommended clinical dose).
Velphoro was not mutagenic, clastogenic or DNA damaging in vitro in the Ames bacterial reverse mutation test, or in the Chinese-hamster fibroblast chromosomal aberration test, or in vivo in the rat Comet assay or peripheral blood micronucleus test.
In rats, mating performance and fertility were unaffected by Velphoro at oral doses up to 800 mg/kg/day (16 times the maximum recommended clinical dose).
13.2 Animal Toxicity and/or Pharmacology
In pregnant rats given up to 800 mg/kg/day Velphoro by oral gavage from Days 6 to 17 post-mating, no embryo-fetal development toxicity was observed. This dose corresponds to 16 times the maximum recommended clinical dose.
In pregnant rabbits given 50, 100 or 200 mg/kg/day Velphoro by oral gavage, from Days 6 to 19 post-mating, the number of fetuses with incomplete/unossified epiphyses and metacarpals/phalanges was increased at the highest dose (corresponding to 4 times the recommended maximum clinical dose). Litter parameters were not adversely affected.
In pregnant rats given Velphoro at 100, 280, or 800 mg/kg/day by oral gavage from Day 6 post-mating to lactation Day 20, offspring body weight gain was lower at age 5-13 weeks and neuromuscular function was delayed at the dose of 800 mg/kg/day. This dose represented 16 times the maximum recommended clinical dose.
14 CLINICAL STUDIES
The ability of Velphoro to lower serum phosphorus in ESRD patients on dialysis was demonstrated in 2 randomized clinical trials: one 6-week, open-label, active-controlled (sevelamer hydrochloride), dose-finding study; and one 55-week, open-label, active-controlled (sevelamer carbonate), parallel-group, safety and efficacy study.
In clinical trials, control of serum phosphorus levels was demonstrated at doses starting from 1,000 mg (2 tablets) per day with treatment effect being observed as early as 1-2 weeks after starting Velphoro.
14.1 Fixed-dose Study
In Study-03A, 154 ES |
