ICH M7“评估和控制药物中DNA反应性（致突变）杂质以限制潜在致癌风险”是一个关于药物致突变杂质的指导原则，旨在为致突变杂质的鉴定、分类、定性和控制提供一个可行的框架方案，以控制其潜在的致癌风险。自ICH M7发布以来，关于DNA反应性（致突变）杂质的指导原则已在全球范围内获得了大量的实践经验，同时也提出了对该类杂质的评估和控制做进一步明确阐述的需求。ICH于2022年5月发布了ICH M7（R2）问答，该文件旨在为ICH M7提供进一步的明确和解释，并对以下2个方面促进和提高一致性和协调性：评估和控制DNA反应性（致突变）杂质的考虑，药品开发、上市许可申请和/或药品主文件中应提供的信息。介绍ICH M7（R2）问答文件的起草背景，对其进行分析和解读，并阐述非临床审评关注点，以促进业界对该文件的理解和运用，以控制杂质的潜在致癌性风险。

ICH M7 "Assessment and Control of DNA Reactive (Mutagenic) Impurities in Pharmaceuticals to Limit Potential Carcinogenic Risk" is a guideline for mutagenic impurities in pharmaceuticals. The purpose of this guideline is to provide a practical framework that is applicable to the identification, categorization, qualification, and control of these mutagenic impurities to limit potential carcinogenic risk. Since the ICH M7 Guideline was finalized, worldwide experience with implementation of the recommendations for DNA reactive (mutagenic) impurities has given rise to requests for clarification relating to the assessment and control of DNA reactive (mutagenic) impurities. ICH M7(R2) Questions and Answers (Q&As) was approved by ICH on May 2022, and the Q&As document is intended to provide additional clarification and to promote convergence and improve harmonization of the considerations for assessment and control of DNA reactive (mutagenic) impurities and of the information that should be provided during drug development, marketing authorization applications and/or Master Files submissions. This article mainly introduces the drafting background and process of ICH M7 (R2) Q&As document, and also introduces and interprets the main content of the document, proposes some points to consider for and the non-clinical reviews, in order to promote the understanding and application of this document, and to limit potential carcinogenic risk of impurities.

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