贝伐珠单抗生物类似药质量相似性评价探讨*

贝伐珠单抗是研发热度最高的生物类似药之一,在梳理国内23家贝伐珠单抗生物类似药厂家研发数据和原研厂家研究数据的基础上,结合目前国内外生物类似药相关指导原则的理念以及相关文献,从生物类似药相似性评价一般原则、贝伐珠单抗关键质量属性识别和相似性评价几个方面,对贝伐珠单抗生物类似药质量相似性的技术评价要点进行初步探讨。     

贝伐珠单抗联合化疗二线及以上治疗晚期非鳞型非小细胞肺癌的临床观察

目的：考察贝伐珠单抗联合化疗二线及以上治疗晚期非鳞型非小细胞肺癌的疗效和安全性。方法：28 例经病理组织学或细胞学证实的晚期非鳞型非小细胞肺癌患者接受贝伐珠单抗联合化疗的二线及以上治疗,其间,贝伐珠单抗所用剂量为7.5 mg ? kg -1,在化疗第1 d 静滴给予;化疗方案包括培美曲塞加或不加铂类、白蛋白结合型紫杉醇加或不加铂类及替吉奥以及吉西他滨/ 紫杉醇/ 多西紫杉醇加或不加铂类。各治疗方案每3 周为1 个周期,持续4 个周期,然后维持治疗,直至受试者不能耐受或疾病进展。按RECIST 1.1 版评价疗效,按NCI-CTC 4.0版评价不良反应。结果：28 例受试者中,无完全缓解病例,部分缓解11 例(39.3％ ),稳定16 例（57.1％ ),进展1 例(3.6％ );客观缓解率为39.3％ (11/28),疾病控制率为96.4％ (27/28);中位无进展生存期为5 个月,中位总生存期为10 个月。亚组数据分析可见,贝伐珠单抗联合化疗各方案亚组中,培美曲塞方案受试者的中位无进展生存期为6 个月,疗效最好,较其他各方案亚组有统计学差异（P=0.028）。安全性数据分析显示,与贝伐珠单抗相关的主要不良反应有Ⅰ ~ Ⅲ度高血压以及Ⅰ / Ⅱ度蛋白尿/ 出血/ 发热。结论：贝伐珠单抗联合化疗用于二线及以上治疗晚期非鳞型非小细胞肺癌的疗效较单纯化疗有一定改善,且毒副反应可耐受,对经济上可以接受的患者值得推荐使用。     

贝伐珠单抗的疗效预测研究现状

抗血管生成的贝伐珠单抗已被广泛应用于多种恶性肿瘤的治疗。但因其受益人群有限及逐渐出现的获得性耐药,也限制了其对患者总生存的改善。迫切需要寻找有效的预测贝伐珠单抗疗效的预测因子指导临床应用。人们在生物标记物、影像学方面进行了大量探索,但目前尚没有一个公认的普遍适用的临床预测指标,仍需要从多角度出发,进行进一步的基础研究及临床研究去发现和验证有效的疗效预测指标。     

LC-MS对奥马珠单抗与其生物类似物CMAB007的分析与结构特征

哮喘是当今世界威胁公共健康的最主要的慢性肺部疾病,作为治疗中重度和难治性哮喘的特效药奥马珠单抗治疗费用相对昂贵,生物类似药CMAB007的研制可以降低治疗费用。本研究用质谱分析一种奥马珠单抗生物类似药CMAB007与原研药的一致性,分别从氨基酸分析、肽图、N/C端序列,还原质谱,寡糖含量,N糖分析等层面对CMAB007和奥马珠单抗进行了系统的比对研究,为进一步临床研究打下基础。结果表明CMAB007和奥马珠单抗氨基酸序列一致,赖氨酸剪切也基本一致,带唾液酸修饰糖形和带核心岩藻糖形比例相近,高甘露糖形比例差异不大,CMAB007略低于奥马珠单抗。因此CMAB007满足生物类似药在结构比对上一致性的要求,有望成为国内首先上市的重组抗人Ig E单克隆抗体药物。     

贝伐珠单抗在肿瘤治疗中的应用研究进展

贝伐珠单抗是一种重组人源化免疫球蛋白 G1 单克隆抗体,可通过抑制血管内皮生长因子活性及抗血管生成,达到抑制肿瘤生长 的目的,目前已广泛用于结直肠癌、肺癌、卵巢癌等多种肿瘤的治疗,尤其是通过与基础化疗结合,能显著提高治疗的有效率以及延长 肿瘤患者的无进展生存期和总生存期。综述贝伐珠单抗的抗肿瘤作用机制、在不同肿瘤治疗中的应用、用于肿瘤治疗时机与疗效差异以 及不良反应和防治。     

贝伐珠单抗联合化疗治疗晚期非鳞非小细胞肺癌的临床观察

目的:观察贝伐珠单抗联合化疗对晚期非小细胞肺癌患者的疗效、安全性及影像学改变。方法:对2007年至2014年于我院治疗的晚期NSNSCLC(非鳞非小细胞肺癌non-squamous non-small cell lung cancer)患者,给予贝伐珠单抗(15 mg/kg或7.5mg/kg)联合化疗(紫杉醇175 mg/m~2,d1,卡铂AUC=5或6,d1,q3 w)6周期及贝伐珠单抗维持治疗(15 mg/kg或7.5 mg/kg,d1,q3w)。观察疗效、不良反应、肺部病灶空洞改变的情况、恶性胸腔积液的治疗效果及部分患者EGFR、KRAS基因突变状况。结果:共观察26例患者,均接受贝伐珠单抗联合化疗,17例行贝伐珠单抗维持治疗。部分缓解(partial response,PR)、疾病稳定(stable disease,SD)、疾病进展(disease progression,PD)率分别为53.8%、42.3%、3.8%。中位无进展生存期(progression free survival,PFS)为11.0个月,中位总生存期(overall survival,OS)达25.8个月。26例患者中15.4%治疗后病变发生空洞改变,空洞组的2年、3年生存率略高于无空洞组,但无统计学差异(P值分别为0.586、0.509)。13例患者伴有恶性胸腔积液,胸腔积液的疾病控制率为100%。11例患者标本可进行EGFR基因检测,敏感突变占36.4%,未突变占63.6%。对10例患者标本行KRAS基因检测,均为突变阴性。不良反应包括骨髓抑制、消化道反应、鼻衄、咯血、高血压、蛋白尿等。大多数不良反应程度较轻,可控制。结论:贝伐珠单抗联合化疗治疗晚期NSNSCLC患者疗效确切,副反应可耐受,控制恶性胸腔积液效果较好。肺部病灶空洞改变的临床意义有待进一步研究。     

西妥昔单抗和贝伐珠单抗治疗晚期结直肠癌的有效性和安全性比较

目的:比较西妥昔单抗和贝伐珠单抗治疗晚期结直肠癌的有效性和安全性。方法:选取2014年1月～2017年8月我院收治的晚期结直肠癌患者100例,根据患者入院先后顺序随机分为两组,所有患者均给予FOLFIRI方案进行化疗,A组在化疗的基础上给予贝伐珠单抗进行治疗,B组在化疗的基础上给予西妥昔单抗进行治疗。比较两组患者临床治疗的缓解率、控制率及不良反应的发生情况,对所有患者随访1年,记录并比较两组患者的无进展生存期。结果:两组患者的缓解率、控制率、恶心呕吐、头晕、延迟性腹泻、肝肾损伤、白细胞减少、血小板减少和尿蛋白的发生率相比均无统计学差异(P0.05),但B组患者骨髓抑制和皮疹的发生率显著高于A组(P0.05);两组患者的无进展生存期相比无统计学差异(P0.05)。结论:西妥昔单抗和贝伐珠单抗治疗晚期结直肠癌的临床效果相当,且不良反应较轻,以Ⅰ～Ⅱ度为主,患者均可耐受,对症治疗后均有所缓解。西妥昔单抗易引发骨髓抑制和皮疹,在临床应用过程中需注意并进行有效预防和积极处理。     

血清VEGF水平与贝伐珠单抗联合化疗治疗转移性结直肠癌患者疗效的关系研究

目的:研究血清血管内皮生长因子(VEGF)水平与贝伐珠单抗联合化疗治疗转移性结直肠癌患者疗效的关系。方法:选取2015年2月至2016年2月间我院收治的转移性结直肠癌患者80例,按照数字随机表法将患者随机分为观察组(n=40)和对照组(n=40)。对照组给予氟尿嘧啶/奥沙利铂(FOLFOX-6)方案治疗,观察组则在此基础上加用贝伐珠单抗5 mg/kg治疗,d1,两组均进行4个化疗周期,比较两组患者临床疗效及治疗前、治疗后血清VEGF水平,并分析血清VEGF与疗效的相关性。结果:观察组有效率(RR)为52.50%(21/40),高于对照组的30.00%(12/40)(P0.05)。治疗前两组患者血清VEGF水平差异无统计学意义(P0.05),治疗后两组患者血清VEGF水平均较治疗前显著降低,观察组患者血清VEGF水平显著低于对照组患者,观察组VEGF下降幅度显著高于对照组(均P0.05)。经秩相关分析显示,结直肠癌患者治疗后VEGF下降幅度与治疗疗效呈显著正相关(r=0.683,P=0.000)。结论:贝伐珠单抗联合化疗治疗转移性结直肠癌可显著降低患者血清VEGF水平,疗效更佳。     

贝伐珠单抗联合紫杉醇/卡铂方案治疗晚期非小细胞肺癌的临床疗效分析

目的:探讨贝伐珠单抗联合紫杉醇/卡铂方案治疗晚期非小细胞肺癌的临床疗效和安全性.方法:选择本研究中心入组SAiL (MO19390)研究的13例患者为研究对象,给予贝伐珠单抗15 mg/kg,化疗d1静点,以后每3周重复;联合化疗方案为175mg/m2紫杉醇,d1,卡铂AUC=6,d1,每3周重复.化疗4-6周期,贝伐珠单抗每3周应用一次直至病情进展.评价患者的不良反应、客观有效率(objective response rate,ORR)、中位无进展生存期(progression free survival,PFS)和总生存期(overall survival,OS).同时,对可取得肿瘤组织标本的患者进行回顾性EGFR和KRAS突变检测.结果:13例患者中,发生5级肺动脉栓塞1例,4级脑梗塞1例,4级蛋白尿2例,3级鼻出血1例,最常见的不良反应为鼻出血(69.2％)、蛋白尿(46.2％)、高血压(38.5％)、咯血(30.8％)、流涕(30.8％)、头晕(23.1％),大多程度较轻可以耐受.部分缓解(partial response,PR)7例(53.8％),疾病稳定(stable disease,SD)6例(46.2),总有效率53.8％,疾病控制率100％,中位PFS 7.7个月,中位OS 16.1个月.6例可进行EGFR和KRAS突变检测的患者中,1例存在EGFR 19外显子缺失突变,1例存在21外显子L858R点突变,4例未检测到EGFR敏感突变,6例患者KRAS突变均为阴性.结论:贝伐珠单抗联合紫杉醇/卡铂方案治疗中国晚期非小细胞肺癌可延长PFS和OS,患者的耐受性良好.     

贝伐珠单抗联合化疗治疗晚期结直肠癌的临床疗效

目的:探讨晚期结直肠癌采用贝伐珠单抗联合化疗的临床疗效,为临床治疗提供参考。方法:按照随机数字表法将2010年2月~2013年2月我院收治的50例晚期结直肠癌患者分为两组,观察组采用贝伐珠单抗联合奥沙利铂,卡培他滨化疗,对照组单用奥沙利铂,卡培他滨进行化疗,比较两组的临床疗效、血清肿瘤标志物浓度变化及不良反应。结果:化疗4个周期后观察组有效率为56.00%高于对照组的24.00%,差异有统计学意义(P0.01),观察组疾病控制率为84.00%高于对照组的60.00%,差异有统计学意义(P0.05);观察组治疗后的CEA、CA242、CA19-9浓度均低于对照组,差异有统计学意义(P0.01);化疗后两组不良反应主要有恶心、呕吐、食欲减低等胃肠道反应,乏力,肝功能损害,骨髓抑制,脱发,贫血以及中性粒细胞下降等,其中观察组乏力,肝功能损害发生率低于对照组,差异有统计学意义(P0.05),其余不良反应两组差异无统计学意义(P0.05)。结论:结直肠癌采用贝伐珠单抗联合化疗治疗具有近期疗效好,安全性高等特点,临床有重要参考价值。     

Assessment of structural and functional similarity of biosimilar products: Rituximab as a case study

Biosimilars are products that are similar in terms of quality, safety, and efficacy to an already licensed reference/ innovator product and are expected to offer improved affordability. The most significant source of reduction in the cost of development of a biosimilar is the reduced clinical examination that it is expected to undergo as compared to the innovator product. However, this clinical relief is predicated on the assumption that there is analytical similarity between the biosimilar and the innovator product. As a result, establishing analytical similarity is arguably the most important step towards successful development of a biosimilar. Here, we present results from an analytical similarity exercise that was performed with five biosimilars of rituximab (Ristova®, Roche), a chimeric mouse/ human monoclonal antibody biotherapeutic, that are available on the Indian market. The results show that, while the biosimilars exhibited similarity with respect to protein structure and function, there were significant differences with respect to size heterogeneity, charge heterogeneity and glycosylation pattern.     

Biosimilars: Challenges and path forward

Development of biosimilar proteins is the fastest growing sector in the biopharmaceutical industry, as patents for the top 10 best-selling biologics will expire within one decade. The world’s first biosimilar of infliximab, Remsima® (CT-P13) made by Celltrion, was approved by the Committee for Medicinal Products for Human Use (CHMP) of European Medicine Agency (EMA) in June 2013. This has ignited competition between related companies for prior occupation of the global market on blockbuster biologics. However, to achieve approval for biosimilars, developing companies face many hurdles in process development, manufacturing, analysis, clinical trials, and CMC (chemical, manufacturing and controls) documentation. Recent evolutionary progress in science, engineering, and process technology throughout the biopharmaceutical industry supports to show similarity between originator and biosimilar products. The totality of evidence has been able to demonstrate the quality, efficacy, and safety of biosimilars whereas a lack of interchangeability and international standards has to be addressed. Further understanding of the timing importance by regulatory agencies will be key to maximizing the value of biosimilars.     

Biosimilars: Key regulatory considerations and similarity assessment tools

A biosimilar drug is defined in the US Food and Drug Administration (FDA) guidance document as a biopharmaceutical that is highly similar to an already licensed biologic product (referred to as the reference product) notwithstanding minor differences in clinically inactive components and for which there are no clinically meaningful differences in purity, potency, and safety between the two products. The development of biosimilars is a challenging, multistep process. Typically, the assessment of similarity involves comprehensive structural and functional characterization throughout the development of the biosimilar in an iterative manner and, if required by the local regulatory authority, an in vivo nonclinical evaluation, all conducted with direct comparison to the reference product. In addition, comparative clinical pharmacology studies are conducted with the reference product. The approval of biosimilars is highly regulated although varied across the globe in terms of nomenclature and the precise criteria for demonstrating similarity. Despite varied regulatory requirements, differences between the proposed biosimilar and the reference product must be supported by strong scientific evidence that these differences are not clinically meaningful. This review discusses the challenges faced by pharmaceutical companies in the development of biosimilars.     

Current perspectives on biosimilars

In this work, an overview of the biosimilars market, pipeline and industry targets is discussed. Biosimilars typically have a shorter timeline for approval (8 years) compared to 12 years for innovator drugs and the development cost can be 10–20% of the innovator drug. The biosimilar pipeline is reviewed as well as the quality management system (QMS) that is needed to generate traceable, trackable data sets. One difference between developing a biosimilar compared to an originator is that a broader analytical foundation is required for biosimilars and advances made in developing analytical similarity to characterize these products are discussed. An example is presented on the decisions and considerations explored in the development of a biosimilar and includes identification of the best process parameters and methods based on cost, time, and titer. Finally factors to consider in the manufacture of a biosimilar and approaches used to achieve the target-directed development of a biosimilar are discussed.

     

Characterization and comparison of commercially available TNF receptor 2-Fc fusion protein products

Because of rapidly increasing market demand and rising cost pressure, the innovator of etanercept (Enbrel®) will inevitably face competition from biosimilar versions of the product. In this study, to elucidate the differences between the reference etanercept and its biosimilars, we characterized and compared the quality attributes of two commercially available, biosimilar TNF receptor 2-Fc fusion protein products. Biosimilar 1 showed high similarity to Enbrel® in critical quality attributes including peptide mapping, intact mass, charge variant, purity, glycosylation and bioactivity. In contrast, the intact mass and MS/MS analysis of biosimilar 2 revealed a mass difference indicative of a two amino acid residue variance in the heavy chain (Fc) sequences. Comprehensive glycosylation profiling confirmed that biosimilar 2 has significantly low sialylated N-oligosaccharides. Biosimilar 2 also displayed significant differences in charge attributes compared with the reference product. Interestingly, biosimilar 2 exhibited similar affinity and bioactivity levels compared with the reference product despite the obvious difference in primary structure and partial physiochemical properties. For a biosimilar development program, comparative analytical data can influence decisions about the type and amount of animal and clinical data needed to demonstrate biosimilarity. Because of the limited clinical experience with biosimilars at the time of their approval, a thorough knowledge surrounding biosimilars and a case-by-case approach are needed to ensure the appropriate use of these products.     

Characterization and comparison of commercially available TNF receptor 2-Fc fusion protein products

Because of rapidly increasing market demand and rising cost pressure, the innovator of etanercept (Enbrel®) will inevitably face competition from biosimilar versions of the product. In this study, to elucidate the differences between the reference etanercept and its biosimilars, we characterized and compared the quality attributes of two commercially available, biosimilar TNF receptor 2-Fc fusion protein products. Biosimilar 1 showed high similarity to Enbrel® in critical quality attributes including peptide mapping, intact mass, charge variant, purity, glycosylation and bioactivity. In contrast, the intact mass and MS/MS analysis of biosimilar 2 revealed a mass difference indicative of a two amino acid residue variance in the heavy chain (Fc) sequences. Comprehensive glycosylation profiling confirmed that biosimilar 2 has significantly low sialylated N-oligosaccharides. Biosimilar 2 also displayed significant differences in charge attributes compared with the reference product. Interestingly, biosimilar 2 exhibited similar affinity and bioactivity levels compared with the reference product despite the obvious difference in primary structure and partial physiochemical properties. For a biosimilar development program, comparative analytical data can influence decisions about the type and amount of animal and clinical data needed to demonstrate biosimilarity. Because of the limited clinical experience with biosimilars at the time of their approval, a thorough knowledge surrounding biosimilars and a case-by-case approach are needed to ensure the appropriate use of these products.     

Worldwide experience with biosimilar development

Limited access for high-quality biologics due to cost of treatment constitutes an unmet medical need in the United States (US) and other regions of the world. The term “biosimilar” is used to designate a follow-on biologic that meets extremely high standards for comparability or similarity to the originator biologic drug that is approved for use in the same indications. Use of biosimilar products has already decreased the cost of treatment in many regions of the world, and now a regulatory pathway for approval of these products has been established in the US. The Food and Drug Administration (FDA) led the world with the regulatory concept of comparability, and the European Medicines Agency (EMA) was the first to apply this to biosimilars. Patents on the more complex biologics, especially monoclonal antibodies, are now beginning to expire and biosimilar versions of these important medicines are in development. The new Biologics Price Competition and Innovation Act allows the FDA to approve biosimilars, but it also allows the FDA to lead on the formal designation of interchangeability of biosimilars with their reference products. The FDA’s approval of biosimilars is critical to facilitating patient access to high-quality biologic medicines, and will allow society to afford the truly innovative molecules currently in the global biopharmaceutical industry’s pipeline.     

Versatile characterization of glycosylation modification in CTLA4-Ig fusion proteins by liquid chromatography-mass spectrometry

CTLA4-Ig is a highly glycosylated therapeutic fusion protein that contains multiple N- and O-glycosylation sites. Glycosylation plays a vital role in protein solubility, stability, serum half-life, activity, and immunogenicity. For a CTLA4-Ig biosimilar development program, comparative analytical data, especially the glycosylation data, can influence decisions about the type and amount of animal and clinical data needed to establish biosimilarity. Because of the limited clinical experience with biosimilars before approval, a comprehensive level of knowledge about the biosimilar candidates is needed to achieve subsequent development. Liquid chromatography-mass spectrometry (LC–MS) is a versatile technique for characterizing N- and O-glycosylation modification of recombinant therapeutic proteins, including 3 levels: intact protein analysis, peptide mapping analysis, and released glycans analysis. In this report, an in-depth characterization of glycosylation of a candidate biosimilar was carried out using a systematic approach: N- and O-linked glycans were identified and electron-transfer dissociation was then used to pinpoint the 4 occupied O-glycosylation sites for the first time. As the results show, the approach provides a set of routine tools that combine accurate intact mass measurement, peptide mapping, and released glycan profiling. This approach can be used to comprehensively research a candidate biosimilar Fc-fusion protein and provides a basis for future studies addressing the similarity of CTLA4-Ig biosimilars.     

The challenge of indication extrapolation for infliximab biosimilars

A biosimilar is intended to be highly similar to a reference biologic such that any differences in quality attributes (i.e., molecular characteristics) do not affect safety or efficacy. Achieving this benchmark for biologics, especially large glycoproteins such as monoclonal antibodies, is challenging given their complex structure and manufacturing. Regulatory guidance on biosimilars issued by the U.S. Food and Drug Administration, Health Canada and European Medicines Agency indicates that, in addition to a demonstration of a high degree of similarity in quality attributes, a reduced number of nonclinical and clinical comparative studies can be sufficient for approval. Following a tiered approach, clinical studies are required to address concerns about possible clinically significant differences that remain after laboratory and nonclinical evaluations. Consequently, a critical question arises: can clinical studies that satisfy concerns regarding safety and efficacy in one condition support “indication extrapolation” to other conditions? This question will be addressed by reviewing the case of a biosimilar to infliximab that was approved recently in South Korea, Europe, and Canada for multiple indications through extrapolation. The principles discussed should also apply to biosimilars of other monoclonal antibodies that are approved to treat multiple distinct conditions.