The rasH2 mouse model for assessing carcinogenic potential of pharmaceuticals

Area of Science:

• Pharmacology
• Toxicology
• Oncology

Background:

• The transgenic rasH2 mouse is a model for carcinogenicity testing.
• Limited data exists for drug candidates in rasH2 mice, hindering its widespread adoption.
• This study addresses the data gap by analyzing 10 pharmaceutical candidates.

Purpose of the Study:

• To evaluate the carcinogenicity of 10 pharmaceutical candidates in the rasH2 mouse model.
• To compare rasH2 mouse findings with traditional 2-year Sprague-Dawley rat bioassays.
• To assess the relevance of rasH2 mouse findings to human carcinogenicity.

Main Methods:

• Conducted 6-month carcinogenicity studies in rasH2 mice for 10 drug candidates.
• Compared rasH2 mouse results with concurrent 2-year Sprague-Dawley rat carcinogenicity studies.
• Analyzed specific tumor types and incidences in both species.

Main Results:

• Only 2 of 10 compounds were positive for carcinogenicity in rasH2 mice.
• Positive rasH2 findings (sunitinib, bazedoxifene) correlated with positive rat study outcomes.
• RasH2 mice showed fewer rodent-specific neoplasms compared to rats, suggesting higher human relevance.

Conclusions:

• The rasH2 mouse model demonstrates a lower incidence of rodent-specific neoplasms than rats.
• Positive carcinogenicity findings in rasH2 mice are generally mirrored in rat studies.
• The rasH2 model shows promise for pharmaceutical carcinogenicity testing with potentially greater human relevance.