Impact on Pharmaceutical Development of the New Addendum to Testing for Carcinogenicity of Pharmaceuticals Within the ICH S1B(R1) Guideline

Explore the transformative changes in pharmaceutical carcinogenicity testing through this keynote presentation delivered by Dr. Frank Sistare, former Scientific Associate Vice President at Merck and Rapporteur of the ICH S1 Carcinogenicity Expert Working Group. Discover how the new addendum to the ICH S1B(R1) Guideline revolutionizes approaches to evaluating carcinogenic potential in small molecule pharmaceuticals by introducing an integrative, mechanism-based Weight of Evidence (WoE) approach that reduces animal testing while maintaining patient safety standards. Learn about the significant updates from the original 1997 guidance, including when 2-year rat studies are now required versus optional, clarifications on high dose identification for rasH2-Tg studies with new plasma exposure ratio-based options, and how these changes align with 3Rs principles for animal welfare. Understand the practical implications for drug development programs, including earlier implementation of mechanism-based carcinogenicity risk assessment, potential timeline changes for safety assessment and marketing approval when 2-year rat studies are not required, and decision-making considerations between 2-year standard mouse studies versus 6-month rasH2 studies. Gain insights into the scientific advances, retrospective analyses, and international prospective studies that support these regulatory updates, and examine real-world applications of how this guidance will impact pharmaceutical development strategies moving forward.