RAT CARCINOGENICITY STUDY WITH GW501516, A
PPAR DELTA AGONIST.
L. E. G
eiger
1
, W. S. Dunsford
2
, D. J. Lewis
2
, C. Brennan
3
, K. C. Liu
3
and S. J.
Newsholme
1
.
1
Safety Assessment, GlaxoSmithKline, King of Prussia, PA,
2
Safety
Assessment, GlaxoSmithKline, Ware, United Kingdom and
3
Huntingdon Life Sciences,
Huntingdon, United Kingdom.
GW501516, a non-genotoxic PPARδ agonist, was assessed for carcinogenic poten-
tial by daily administration (oral gavage) to Han Wistar rats for a period of 104
weeks. Males were given 0, 5, 15 or 30 mg/kg/day for the first 6 weeks of the study.
For the remainder of the study males were given 0, 5, 20 or 40 mg/kg/day. Females
were given 0, 3, 10 or 20 mg/kg/day for the entire study. GW501516 produced test
article-related neoplastic findings in multiple tissues at all doses. Increased mortal-
ity was seen with females given GW501516 at all doses and uterine endometrial
adenocarcinoma contributed to death in a high proportion of these animals.
Neoplasms considered test-article related occurred in the liver (hepatocellular ade-
noma at ≥10 mg/kg/day), urinary bladder (transitional cell carcinoma in males
given 20 and 40 mg/kg/day), thyroid (follicular cell adenoma at
≥3 mg/kg/day and carcinoma in males at ≥20 mg/kg/day), tongue (squamous cell papilloma in males at 5 mg/kg/day and 40 mg/kg/day), stomach (squamous cell papilloma in males at ≥5 mg/kg/day and a female at 20 mg/kg/day, and carcinoma in a male at 40 mg/kg/day and a female at 3 mg/kg/day), skin (inverted squamous cell papilloma in males at ≥5 mg/kg/day and females at 3 or 20 mg/kg/day), Harderian glands (ade-noma in males at ≥5 mg/kg/day and adenocarcinoma in a male at 40 mg/kg/day),
testes (interstitial cell adenoma at 40 mg/kg/day), ovary (Sertoli cell adenoma at
≥10 mg/kg/day) and uterus (polyp and endometrial adenocarcinoma at≥3
mg/kg/day). Some of the tumor types observed in this study have not been reported
with either PPARα or PPARγ agonists and may reflect tumor promotion mediated though
PPARδ agonism.