title: Regulatory Forum commentary: alternative mouse models for future cancer risk assessment.
abstract: International regulatory and pharmaceutical industry scientists are discussing revision of the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) S1 guidance on rodent carcinogenicity assessment of small molecule pharmaceuticals. A weight-of-evidence approach is proposed to determine the need for rodent carcinogenicity studies. For compounds with high human cancer risk, the product may be labeled appropriately without conducting rodent carcinogenicity studies. For compounds with minimal cancer risk, only a 6-month transgenic mouse study (rasH2 mouse or p53+/- mouse) or a 2-year mouse study would be needed. If rodent carcinogenicity testing may add significant value to cancer risk assessment, a 2-year rat study and either a 6-month transgenic mouse or a 2-year mouse study is appropriate. In many cases, therefore, one rodent carcinogenicity study could be sufficient. The rasH2 model predicts neoplastic findings relevant to human cancer risk assessment as well as 2-year rodent models, produces fewer irrelevant neoplastic outcomes, and often will be preferable to a 2-year rodent study. Before revising ICH S1 guidance, a prospective evaluation will be conducted to test the proposed weight-of-evidence approach. This evaluation offers an opportunity for a secondary analysis comparing the value of alternative mouse models and 2-year rodent studies in the proposed ICH S1 weight-of-evidence approach for human cancer risk assessment.
authors: Pfizer, Inc., Cambridge, Massachusetts, USA dan.g.morton@pfizer.com.
authors: Daniel
authors: D
authors: Morton
authors: Merck & Co., West Point, Pennsylvania, USA.
authors: Frank D
authors: FD
authors: Sistare
authors: Pfizer, Inc., Groton, Connecticut, USA.
authors: Prashant R
authors: PR
authors: Nambiar
authors: Novartis Pharmaceutical Corporation, East Hanover, New Jersey, USA.
authors: Oliver C
authors: OC
authors: Turner
authors: Pfizer, Inc., Cambridge, Massachusetts, USA.
authors: Zaher
authors: Z
authors: Radi
authors: Eisai, Inc., Woodcliff Lake, New Jersey, USA.
authors: Nancy
authors: N
authors: Bower
mesh_terms: D000818:Animals; D015197:Carcinogenicity Tests / Q000592:standards*; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical; D004345:Drug Industry; D064420:Drug-Related Side Effects and Adverse Reactions; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D009369:Neoplasms / Q000188:drug therapy*; D018570:Risk Assessment
keywords: ICH S1; carcinogenicity; mouse; p53+/−; pharmaceutical; rasH2; rat; regulatory guidance; rodent