This guidance is intended to assist sponsors in designing trials to support marketing approval of drugs and biological products for the treatment of high-risk early-stage breast cancer in the neoadjuvant (preoperative) setting. The main focus of the guidance is to discuss the use of pathological complete response (pCR) in high-risk early-stage breast cancer as a potential endpoint to support approval under the accelerated approval regulations (21 CFR part 314, subpart H, for new drug applications and 21 CFR part 601, subpart E, for biologics license applications). The objectives of the guidance are to:
• Describe acceptable definitions of pCR for regulatory purposes
• Briefly summarize what is currently known about the relationship between pCR and prognosis
• Describe trial designs and patient populations in which pCR may be accepted as reasonably likely to predict clinical benefit
• Provide guidance regarding trial designs to verify clinical benefit in support of traditional approval