EMEA基因毒性杂质限度指引

1、20060628 EMEA/CHMP/QWP/251344/2006基因毒性杂质限度指南(中英文对照)London, 28 June 2006CPMP/SWP/5199/02EMEA/CHMP/QWP/251344/2006The European Agency for the Evaluation of Medicinal Products欧洲共同体药物评审委员会(EMEA)COMMITTEE FOR MEDICINAL PRODUCTS FOR HUMAN USE人用约品委员会(CHMP)GUIDLINE ON THE LIMITS OF GENOTOXIC IMPURITIES基因毒性杂

2、质限度指南DESCUSSION IN THE SAFETY WORKING P/平安工作组之内的讨论XRTJJune 2002-October 2002TRANSMISSION TO CPMPCPM赧递December 2002RELEASE FOR CONSULTATION专家讨论December 2002DEADLINE FOR COMMENTS建议收集最后期限March 2003DISCUSSIONN THESAFETYVORKINPARTYKNtQUALITY WORKING PARTY平安工作组和质量工作组之间的讨论D June 2003-February 2004TRANSMISS

3、ION TO CPMPMarch 2004转移给CPMPRE-RELEASE FOR CONSULTATIONJune 2004再次放行给参谋团DEADLINE FOR COMMENTSDecember 2004收集意见的最后期限DISCUSSION THESAFETYWORKINPARTAND February 2005-May 2006QUALITY WORKING PARTY平安工作组和质量工作组之间的讨论ADOPTION BY CHMP28 June 2006被CHM睬用DATE FOR COMING INTO EFFECT01January 2007生效日期KEYWORDS Impu

4、rities; Genotoxicity; Threshold of toxicological关键词concern (TTC); Structure activity relationship (SAR)GUIDLINE ON THE LIMITS OF GENOTOXIC IMPURITIES基因毒性杂质限度指南TABLE OF CONTENTS 录EXECUTIVE SUMMARY 摘要31. INTRODUCTION绍32. SCOPE 范围33. LEGAL BASIS 法律依 据34. TOXICOLOGICAL BACKGROUND 学背景45. RECOMMENDATION议4

5、5.1 Genotoxic CompoundSWith Sufficient Evidence for a Threshold-Related Mechanism具有充分证据证实其阈值相关机理的基因毒性化合物45.2 Genotoxic Compounds Without Sufficient Evidence for a Threshold-Related Mechanism不具备充分证据支持其阈值相关机理的基因毒性化合物55.2.1 Pharmaceutical Assessment 药学评 价.55.2.2 Toxicological Assessment毒理学评价.55.2.3 App

6、lication of a Threshold of Toxicological Concern毒理学担忧阈值应用55.3 Decision Tree for Assessment of Acceptability of Genotoxic Impurities基因毒性杂质可接受性评价决策树7REFERENCE爹考文献8EXECUTIVE SUMMARY 摘要The toxicological assessment of genotoxic impurities and the determination of acceptable limits for such impurities in

7、active substances is a difficult issue and not addressed in sufficient detail in the existing ICH Q3X guidances. The data set usually available for genotoxic impurities is quite variable and is the main factor that dictates the process used for the assessment of acceptable limits. In the absence of

8、data usually needed for the application of one of the established risk assessment methods, i.e. data from carcinogenicity long-term studies or data providing evidence for a threshold mechanismof genotoxicity, implementation of a generally applicable approach as defined by the Threshold of Toxicologi

9、cal Concern (TTC) is proposed.A TTC value of 1.5 仙 g/day intake of a genotoxic impurity is considered to be associated with an acceptable risk (excess cancer risk of <1 in 100,000 over a lifetime) for most pharmaceuticals. From this threshold value, a permitted level in the active substance can b

10、e calculated based on the expected daily dose. Higher limits maybe justified under certain conditions such as short-term exposure periods.基因毒性杂质的毒理学评估和这些杂质在活性药物中的可接受标准的测定是一件困难的 事情,并且在现有的ICH Q3X指南中也没有详细的规定.现有的关于基因毒性杂质的相关数 据是容易变化的,也是对杂质可接受标准如何进行评价的主要影响因素.如果缺少风险评估 方法所需要的数据,比方,致癌作用的长期研究数据,或为基因毒性的阀值提供证据的

11、数据, 一般建议使用一般通用的被定义为毒理学关注的阈值(TTQ的方法.一个“ 1.5仙g/day的TTC值,即相当于每天摄入1.5 pg的基因毒性杂质,被认为对于大多数药品来说是可以接 受的风险(一生中致癌的风险小于十万分之1).根据这个阀值,可以根据这个预期的每日摄 入量计算出活性药物中可接受的杂质水平.较高的临界值可以在特定的条件下,如短期暴露 周期等,进行推算.1. INTRODUCTION 介绍A general concept of qualification of impurities is described in the guidelines for active substa

12、nces (Q3A, Impurities in New Active Substances) or medicinal products (Q3B, Impurities in New Medicinal Products), whereby qualification is defined as the process of acquiring and evaluating data that establishes the biological safety of an individual impurity or a given impurity profile at the leve

13、l(s) specified. In the case of impurities with a genotoxic potential, determination of acceptable dose levels is generally considered as a particularly critical issue, which is not specifically covered by the existing guidelines.在原料药(Q3A和药物制剂(Q3B的杂质指导原那么中,杂质限度确定的依据包括各个 杂质的生物平安性数据或杂质在某特定含量水平的研究概况.而对于

14、遗传毒性杂质限度确实定,通常都认为是特别关键的问题,但目前尚无相关的指导原那么.2. SCOPE 范围This Guideline describes a general framework and practical approaches on how to deal with genotoxic impurities in new active substances. It also relates to new applications for existing active substances, where assessment of the route of synthesis,

15、process control and impurity profile does not provide reasonable assurance that no new or higher levels of genotoxic impurities are introduced as compared to products currently authorised in the EU containing the same active substance. The samealso applies to variations to existing Marketing Authori

16、sations pertaining to the synthesis. The guideline does, however, not need to be applied retrospectively to authorised products unless there is a specific cause for concern.本指导原那么阐述了如何处理新原料药中遗传毒性杂质的一般框架和实际方法.该指导原 那么也适用于已有原料药的新申请,如果其合成路线、过程限制和杂质研究尚无法保证不会产 生新的或更高含量的遗传毒性杂质(与EU目前批准的相同原料药相比).该指导原那么同样适用于已

17、上市原料药有关合成方面的补充申请.除非有特殊原因,本指导原那么不适用于已上市 的产品.In the current context the classification of a compound(impurity) as genotoxic in general meansthat there are positive findings in established in vitro or in vivo genotoxicity tests with the main focus on DNA reactive substances that have a potential for di

18、rect DNA damage. Isolated in vitro findings may be assessed for in vivo relevance in adequate follow-up testing. In the absence of such information in vitro genotoxicants are usually considered as presumptive in vivo mutagens and carcinogens.目前对于基因毒性杂质的分类主要是指：在以DN版应物质为主要研究对象的体内体外试验中,如果发现它们对DNAt潜在的破坏

19、性,那可称之为基因毒性.如果有足够的后续试 验,可由单独的体外试验结果,对它的体内关联性进行评估.在缺乏这样的信息时,体外基 因毒性物质经常被考虑为假定的体内诱变剂和致癌剂.3. LEGAL BASIS法规依据This guideline has to be read in conjunction with Directive 2001/83/EC (as amended) and all relevant CHMP Guidance documents with special emphasis on:在阅读该指南时有必要参考“ Directive 2001/83/EC以及相关的CHMP旨南

20、文件,特别 是以下几个指南：Impurities Testing Guideline: Impurities in New Drug Substances (CPMP/ICH/2737/99, ICHQ3A(R)Note for Guidance on Impurities in New Drug Products (CPMP/ICH/2738/99, ICHQ3B (R)Note for Guidance on Impurities: Residual Solvents (CPMP/ICH/283/95)Note for Guidance on Genotoxicity: Guidance

21、on Specific Aspects of Regulatory Genotoxicity Tests for Pharmaceuticals (CPMP/ICH/141/95, ICHS2A)Note for Guidance on Genotoxicity: A Standard Battery for Genotoxicity Testing of Pharmaceuticals (CPMP/ICH/174/95, ICHS2B)4. TOXICOLOGICAL BACKGROUND里学背景According to current regulatory practice it is a

22、ssumedthat (in vivo) genotoxic compounds have the potential to damage DNA at any level of exposure and that such damage may lead/contribute to tumour development. Thus for genotoxic carcinogens it is prudent to assume that there is no discernible threshold and that any level of exposure carries a ri

23、sk.根据目前的研究实践,具有(体内)遗传毒性的化合物在任何暴露量下都有可能对DNA产生损伤,而这种损伤可能会引发月中瘤.因此,对于遗传毒性致癌物质,应谨慎认为不存在 明确的阈值,任何暴露量下都存在风险.However, the existence of mechanisms leading to biologically meaningful threshold effects is increasingly acknowledged also for genotoxic events. This holds true in particular for compounds interact

24、ing with non-DNA targets and also for potential mutagens, which are rapidly detoxified before coming into contact with critical targets. The regulatory approach to such chemicals can be based on the identification of a critical no-observed-effect level (NOEL) and use of uncertainty factors.然而,对于一些遗传

25、毒性事件,其产生生物学意义的阈值效应的机理正越来越为人所了 解.对于非DNA巴点的化合物和潜在致突变剂更是如此,由于它们在与关键靶点接触前就已 经去毒化了.对于这些化合物,研究的根底可以是确定关键的未观察到影响的剂量( NOEL 和米用不确定因子.Even for compounds which are able to react with the DNA molecule, extrapolation in a linear manner from effects in high-dose studies to very low level (human) exposure may not

26、be justified due to several protective mechanisms operating effectively at low doses. However, at present it is extremely difficult to experimentally prove the existence of threshold for the genotoxicity of a given mutagen. Thus, in the absence of appropriate evidence supporting the existence of a t

27、hreshold for a genotoxic compound making it difficult to define a safe dose it is necessary to adopt a concept of a level of exposure that carries an acceptable risk.即使对能与DN协子发生反响的化合物,由于低剂量时有多种有效的保护机制存在,而 不能将高剂量下的影响以线性方式外推到很低的(人)暴露水平.不过,目前要用实验方法 证实某诱变剂的遗传毒性阈值仍然非常困难.所以,在缺乏恰当的证据支持遗传毒性阈值存 在的情况下,确定平安剂量很

28、困难,因此非常有必要采用一个可接受风险的暴露水平概念.5. RECOMMENDATIONS®.As stated in the Q3A guideline, actual and potential impurities most likely to arise during synthesis, purification and storage of the new drug substance should be identified, based on a sound scientific appraisal of the chemical reactions involved

29、 in the synthesis, impurities associated with raw materials that could contribute to the impurity profile of the new drug substance, and possible degradation products. This discussion can be limited to those impurities that might reasonably be expected based on knowledge of the chemical reactions an

30、d conditions involved. Guided by existing genotoxicity data or the presence of structural alerts, potential genotoxic impurities should be identified. When a potential impurity contains structural alerts, additional genotoxicity testing of the impurity, typically in a bacterial reverse mutation assa

31、y, should be considered Dobo et al.2006, M u ller et al. 2006. While according to the Q3A guideline such studies canusually be conducted on the drug substance containing the impurity to be controlled, studies using isolated impurities are much more appropriate for this purpose and highly recommended

32、.正如Q3A旨导原那么所述,根据合理的化学反响机理分析,在新的原料药合成、纯化和贮 存过程中很有可能产生实际的和潜在的杂质.依据现有的“可能引起遗传毒性的结构数据库,潜在的遗传毒性杂质应能被确认.如果潜在的杂质含有可引起遗传毒性的结构单元,该 杂质应考虑进行遗传毒性试验一般是细菌回复突变试验Dobo等,2006.虽然Q3A旨导原那么认为这些研究采用含有那些需限制杂质的原料药进行是可行的,但用别离出来的杂质进行这些研究更恰当,也是高度推荐的方法.For determination of acceptable levels of exposure to genotoxic carcinogens

33、considerations of possible mechanisms of action and of the dose-response relationship are important components. Based on the above considerations genotoxic impurities may be distinguished into the following two classes:根据以上论述,遗传毒性杂质可以归纳成以下两类：-Genotoxic compounds with sufficient experimental evidence

34、 for a threshold-related mechanism有充分阈值相关机理证据实验的遗传毒性化合物-Genotoxic compounds without sufficient experimental evidence for a threshold-related mechanism无充分阈值相关机理证据实验的遗传毒性化合物5.1 Genotoxic Compounds With Sufficient Evidence for a Threshold-Related Mechanism具有充分证据证实其阈值相关机理的基因毒性化合物Examples of mechanisms o

35、f genotoxicity that may be demonstrated to lead to non-linear or thresholded dose-response relationships include interaction with the spindle apparatus of cell division leading to aneuploidy, topoisomerase inhibition, inhibition of DNAsynthesis, overloading of defence mechanisms, metabolic overload

36、and physiological perturbations (e.g. induction of erythropoeisis, hyper- or hypothermia).非线性或阈值明确的剂量效应关系的遗传毒性机理包括：与细胞分化过程中纺锤体相互 作用；拓扑异构酶抑制；DN的成抑制；过度的防御机制；代谢过度和生理性干扰(如诱导 红血球生成,高体温和低体温).For (classes of) compounds with clear evidence for a thresholded genotoxicity, exposure levels which are without ap

37、preciable risk of genotoxicity can be established according to the procedure as outlined for class 2 solvents in the Q3c Note for Guidance on Impurities: Residual Solvents. This approach calculates a" PermittedDaily Exposure (PDE), which is derived from the NOEL,or the lowestobserved effect lev

38、el (LOEL) in the most relevant (animal) study using "uncertainty factors " (UF).有明确遗传毒性阈值的化合物,不产生遗传毒性风险的暴露水平可以被确定,方法可参 照Q3c杂质指导原那么中二类溶剂的限度确定方法.该方法可计算“每日最大允许暴露量 (PDE,数据来源于“不确定因数动物研究中的 NOEL(未观察到效果的最低水平)或观察到效果的最低水平(LOEL.5.2 Genotoxic Compounds Without Sufficient Evidence for a Threshold-Relat

39、ed Mechanism不具备充分证据支持其阈值相关机理的基因毒性化合物The assessment of acceptability of genotoxic impurities for which no threshold mechanisms are identified should include both pharmaceutical and toxicological evaluations. In general, pharmaceutical measurements should be guided by a policy of controlling levels to

40、“as low as reasonably practicable (ALARP principle),where avoiding is not possible. Levels considered being consistent with the ALARP principle following pharmaceutical assessment should be assessed for acceptability from a toxicological point of view (see decision tree & following sections).对于此

41、类遗传毒性杂质,研究应包括药学和毒理学评估.总之,如果杂质无法防止,药 学方面的限制应遵循“合理可行的最低限量原那么(ALARPM那么).符合ALARPM那么的杂质水平再经毒理学方面的进一步评估,以验证其合理性(见决策树和以下章节).5.2.1 Pharmaceutical Assessment 药学评价A specific discussion as part of the overall discussion on impurities (see Q3A(R) should be provided in the application with regard to impurities w

42、ith potential genotoxicity.申请材料应提供关于潜在遗传毒性杂质的特别讨论资料(见Q3A(R)oA rationale of the proposed formulation/manufacturing strategy should be provided based on available formulation options and technologies. The applicant should highlight, within the chemical process and impurity profile of active substance,

43、 all chemical substances, used as reagents or present as intermediates, or side-products, known as genotoxic and/or carcinogenic (e.g. alkylating agents).需要根据现在的配方选择和技术,提供证实所选的配方/生产策略合理性的证据.申请人 应在合成工艺和杂质研究局部重点指出所有的化学物质,包括用到的试剂、中间体、副产物,哪些是遗传毒性和/或致癌性物质(如烷化剂).More generally, reacting substances and sub

44、stan ces which show “alerting structure “ in terms of genotoxicity which are not shared with the active substance should be considered (see e.g. Dobo et al. 2006). Potential alternatives which do not lead to genotoxic residues in the final product, should be used if available.值得关注的是,虽然有些含有“可能引起遗传毒性的

45、结构(alerting structure )的反响试剂与最终活性物质并没有共同结构,但也要考虑它们的遗传毒性(see e.g. Doboet al.2006). o如果有可能,应该对它们进行一些替代研究,以使最终产品中不会引入基因毒性残 留.A justification needs to be provided that no viable alternative exists, including alternative routes of synthesis or formulations, different starting materials. This might for in

46、stance include cases where the structure, which is responsible for the genotoxic and/or carcinogenic potential is equivalent to that needed in chemical synthesis (e.g. alkylation reactions).需要提供充分的论证来说明没有可行的替代方法存在,包括可替代的合成路线或配方, 不同的起始物料等.比方,应证实具有遗传毒性和/或致癌性的结构在化学合成中(如烷化反响)是必需的.If a genotoxic impurity

47、 is considered to be unavoidable in a drug substance, technical efforts (e.g. purification steps) should be undertaken to reduce the content of the genotoxic residues in the final product in compliance with safetyneeds or to a level as low as reasonably practicable (see safety assessment). Data on c

48、hemical stability of reactive intermediates, reactants, and other components should be included in this assessment.如果遗传毒性杂质在原料中不可防止,那么应该采取适当的技术(如纯化步骤)降低该杂 质的含量,以满足平安性要求,或符合“合理可行的最低限量原那么(见平安评估).药学评估还应包括反响中间体、反响物和其它组件等的化学稳定性研究.Detection and/or quantification of these residues should be done by state-o

49、f-the-art analytical techniques.应该使用比拟先进的分析检测技术来检测和量化这些残留的杂质.5.2.2 Toxicological Assessment毒理学评价The impossibility of defining a safe exposure level (zero risk concept) for genotoxic carcinogens without a threshold and the realization that complete elimination of genotoxic impurities from drug substa

50、nces is often unachievable, requires implementation of a concept of an acceptable risk level, i.e. an estimate of daily humanexposure at and below which there is a negligible risk to humanhealth.鉴于在没有明确阈值的前提下定义平安暴露水平(零风险)是不可能的,且从原料药中 完全除去遗传毒性杂质经常是很难做到的,所以有必要提出一个“可接受风险水平(acceptable risk level )的概念,比方

51、估算一个“每日最大暴露量值,低于该暴露量 时就可以忽略其对人体健康的风险.Procedures for the derivation of acceptable risk levels are considered in the Appendix 3 of the Q3c Note for Guidance on Impurities: Residual Solvents for Class 1 solvents. However, these approaches require availability of adequate data from long-term carcinogeni

52、city studies.对于可接受风险水平的推导过程请参见Q3c(杂质指南注释：一类溶液残留)中的附件三.然而,应用这些方法必须有足够多的长期致癌性研究数据.In most cases of toxicological assessment of genotoxic impurities only limited data from in vitro studies with the impurity (e.g. Amestest, chromosomal aberration test) are available and thus established approaches to de

53、termine acceptable intake levels cannot be applied. Calculation of“safety multiples “ from in vitro dat a(e.g. Amestest) are considered inappropriate for justification of acceptable limits.Moreover, negative carcinogenicity and genotoxicity data with the drug substance containing the impurity at low

54、 ppm levels do not provide sufficient assurance for setting acceptable limits for the impurity due to the lack of sensitivity of this testing approach. Even potent mutagens and carcinogens are most likely to remain undetected whentested as part of the drug substance, i.e. at very low exposure levels

55、.A pragmatic approach is therefore needed which recognises that the presence of very low levels of genotoxic impurities is not associated with an unacceptable risk.大多数情况下,遗传毒性杂质的毒理学评估只是局限于杂质的体外研究如Ames试验,染色体畸变试验,但这些方法并不适用于确定杂质可接受的摄入水平.也就是说,根据体 外数据如Ames试验计算杂质白“平安倍数safety multiples 、进而确定可接受 的限度,是不适宜的.止

56、匕外,用含有较低ppm级杂质水平的原料药研究其致癌性和遗传 毒性,即使得出阴性结果也缺乏以保证该杂质限度的合理性,由于这种试验方法缺少必要的 灵敏度.有些具有很强致突变性和致癌性物质与原料药一起进行试验时,由于在非常低的暴 露水平情况下,很有可能由于低于检测限而无法检出.所以,如果熟悉到含量非常低的遗传 毒性杂质不存在“不可接受的风险 unacceptable risk ,那么可以采取实用的方法来控 制该杂质.5.2.3 Application of a Threshold of Toxicological Concern毒理学相关的阈值应用A threshold of toxicologic

57、al concern (TTC) has been developed to define a common exposure level for any unstudied chemical that will not pose a risk of significant carcinogenicity or other toxic effects (Munro et al. 1999, Kroes and Kozianowski2002). This TTC value was estimated to be 1.5g g/person/day. The TTC, originallyde

58、veloped as a "threshold of regulation " at the FDA for food contact materials (Rulis 1989, FDA1995) was established based on the analysis of 343 carcinogens from a carcinogenic potency database (Gold et al. 1984) and was repeatedly confirmed by evaluations expanding the database to more than 700 carcinogens (Munro 1990, Cheeseman et al. 1999, Kroes et al. 2004). The probability distribution of carcinogenic potencies has been used to derive an estimate of a daily exposure level (n g/person) of most carcinogens which wo