Clinical safety of biosimilar recombinant human erythropoietins

Introduction: A "biosimilar" or "similar biological medicinal product" is a biological agent that is similar in terms of quality, safety, and efficacy to an authorized reference biological medicine. Since the expiration of the epoetin alfa patent in Europe, three agents have received marketing authorization from the European Medicines Agency: Binocrit (epoetin alfa; aka Abseamed and Epoetin Alfa Hexal), Retacrit (epoetin zeta; aka Silapo), and Eporatio (epoetin theta; aka Biopoin and Ratioepo). Areas covered: Using the EMA dossiers and journal publications, this article reviews clinical safety data for these products, with emphasis on serious/severe adverse events and a special consideration of immunogenicity, venous thromboembolism, and mortality. Expert opinion: A review of the available safety evidence shows that all three agents discussed have similar safety profiles. None were statistically higher on safety parameters to what is known about ESA as a class, when stratified by population. As with ESAs in general, immunogenicity, venous thromboembolism, and mortality are all concerns. What is known about ESAs regarding safety can be extended to biosimilar erythropoietins. Since biosimilars are unique, complex biological molecules, safety profiles may evolve from common to differentiated, once long-term product-specific safety data are available. Large-sample, long-term, observational studies of real-world practice will provide the heterogeneity and statistical power to demonstrate product-specific effectiveness and safety profiles. Statistically, out of the commercially available formulations of the three products reviewed, no single product is less or more safe.     

Non-clinical vaccine safety assessment

As vaccines are undoubtedly classified as pharmaceuticals, they have to be submitted to strict non-clinical safety evaluation. The context of their prophylactic use requires that every effort is made to ensure their safe use. Their safety evaluation is complex as they act through a multistage mechanism in which the vaccine by itself acts as a pro-drug, antibodies and activated lymphocytes being the actual effectors. Therefore, several potential toxicities must be considered: direct toxicity of the test article, toxicity linked to the pharmacodynamic activity of the vaccine, activation of pre-existing disorders, toxicity of contaminants and impurities and other adverse reactions due to interaction between the various components. Guidelines dealing with vaccines include general guidelines applicable to all pharmaceuticals, such as ICH S6, and also more specific documents which allow some flexibility in study design. Among the various studies, if single-dose studies are generally part of the quality control test battery, repeated dose studies are pivotal. The animal model and treatment schedule selection and the parameters investigated are critical for the relevance of this safety assessment. Immunological and safety pharmacology parameters should be adapted to the specific properties of vaccines and added to this type of study. Vaccines intended for pregnant women or women of child-bearing age require embryo-fetal and post-natal studies with an adapted design to obtain appropriate fetal and maternal exposure during gestation with continuation into the post-natal period. Tests exist to detect hypersensitivity or autoimmune reactions, but require further validation. In addition to this tailor-made approach, any adjuvant or active component added to the vaccine formulation necessitate their own assessment using studies routinely performed for new drugs. From this review, vaccine toxicology would appear to be a separate discipline on its own whose predictivity will be increased by new method development.     

Epoetin: human recombinant erythropoietin

The chemistry, pharmacology, pharmacokinetics, clinical uses and efficacy, adverse effects, drug interactions, dosage and administration, and formulary considerations of epoetin are described. Erythropoietin, a glycoprotein hormone primarily synthesized in the kidney, is the chief regulator of red blood cell production. Erythropoietin concentrations increase in response to a hypoxic state, resulting in increased red blood cell formation, accelerated hemoglobin production, and premature movement of reticulocytes into the circulation. The human gene responsible for the production of erythropoietin recently was cloned, and the recombinant product--epoetin--has been made available through mass production. The apparent volume of distribution of i.v. epoetin approximates the assumed plasma volume both in healthy volunteers and in patients with chronic renal failure. Little is known about the metabolism and route of elimination of epoetin and erythropoietin. Epoetin recently was approved by the FDA for treatment of anemia associated with chronic renal failure. Clinical trials in patients receiving hemodialysis or peritoneal dialysis and in predialysis patients with renal dysfunction demonstrate epoetin's efficacy. Other potential indications include augmentation of blood production in patients enrolled in autologous blood donation programs and treatment of anemias associated with rheumatoid arthritis, sickle cell disease, acquired immunodeficiency syndrome, cancer, and premature birth. The most frequent adverse effect associated with epoetin therapy is the worsening or development of hypertension. Other adverse effects include thrombocytosis, hyperkalemia, rise in serum urea concentration, iron deficiency, and flu-like symptoms. No drug interactions with epoetin have been reported in humans. The recommended starting epoetin dosage in patients with chronic renal failure is 50-100 IU/kg three times weekly. Epoetin is available only as an injection for i.v. or s.c. administration. Epoetin provides a new therapeutic approach to the treatment of anemia associated with chronic renal failure in hemodialysis, peritoneal dialysis, and predialysis patients. Benefits of epoetin therapy include reduced need for blood transfusions, the amelioration of anemic symptoms, and an improved quality of life.     

Genotoxicity studies on HM10760A,recombinant human erythropoietin conjugated to globin fragment

HM10760A is a recombinant human erythropoietin chemically conjugated to the N-terminus of human immunoglobulin Fc fragment through a polyethylene glycol linker. HM10760A was shown to have a relatively long half-life, compared with unconjugated recombinant erythropoietin. In this study, the genotoxicity of HM10760A was investigated by using a test battery of three different methods. In the Ames assay, five strains (TA100, TA1535, TA98, TA1537, and Escherichia coli WP2 uvrA) were tested at six concentrations of 3.13, 6.25, 12.5, 25, 50, and 100?μg/plate. HM10760A did not increase the number of revertant colonies in any tester strains with and without metabolic activation by rat-liver S9 mix. Subsequently, in vitro chromosomal aberration test, using Chinese hamster lung cells, were conducted at the concentrations of 25, 50, and 100?μg/mL. HM10760A did not induce chromosomal aberrations either in the short-period (6 hours) test with or without rat-liver S9 mix or in the continuous-treatment (24 hours) test. In the in vivo bone marrow micronucleus assay using the male ICR (imprinting control region) mouse, HM10760A was subcutaneously administered twice at 24-hour intervals at doses of 0, 150, 300, and 600?μg/kg. HM10760A produced a slight, but statistically significant, increase in the frequency of micronucleated polychromatic erythrocytes at 600?μg/kg. However, no biological significance was assumed, because this value was within the historical control range. From these findings obtained from the genotoxicity assays performed in this study, it appears unlikely that HM10760A acts as a genotoxic agent in vitro and in vivo.     

Preparation of iodine labeled recombinant human erythropoietin

125I-labelled recombinant human erythropoietin (125I-rh-EPO; CAS for EPO: 11096-26-7) was prepared by using iodo-gen (1,3,4,6-tetrachloro-3,6-diphenylglycouril), which showed a similar immunoreactivity to anti rh-EPO anti-rabbit serum and a similar pharmacokinetics with that of non-labeled rh-EPO.     

Comparative pharmacokinetics and distribution of human urinary erythropoietin and recombinant human erythropoietin in rats.

Comparative pharmacokinetic and distribution studies of human recombinant erythropoietin (rh-EPO, Epoch, CAS 11096-26-7) and human urinary erythropoietin (u-EPO) were performed in rats. The pharmacokinetic parameters following intravenous administration of rh-EPO were similar to those of u-EPO. With respect to the concentrations of radioactivity in the liver reflecting uptakes of asialoglycoprotein, there were no differences in the concentrations between 125I-rh-EPO and 125I-u-EPO. The concentrations of radioactivity in the target organs, i.e., bone marrow and spleen in rats given 125I-rh-EPO were very similar to those of rats given 125I-u-EPO. These facts are most likely to reflect the similarity in pharmacological action.     

冻干人用狂犬病疫苗(MRC-5细胞)非临床安全性研究

目的 对冻干人用狂犬病疫苗(MRC-5细胞)进行全身主动过敏试验、肌肉刺激性、单次给药毒性和溶血性评价,以考察其安全性.方法 本研究起止时间为2014年3月至2016年10月.按照确定的工艺和质量标准,使用人二倍体细胞MRC-5培养狂犬病固定毒株,灭活、纯化后制备冻干人用狂犬病疫苗,质量检定合格后,用于开展全面的动物毒...     

大剂量重组人促红细胞生成素治疗腹透患者贫血的临床疗效

目的 :观察重组人促红细胞生成素 (r HuEPO) 1万U ,qw ,在改善腹透患者贫血的有效性及其药物不良反应。方法 :从上海 3家医院的腹透患者中选择透析稳定的贫血患者 4 8例 ,给予r HuEPO 1万U ,sc ,qw ,疗程 6mo ,期间如Hb快速上升至 10 0g·L-1,减量至每 2wk 1次或更少。分别于给药前和给药后wk 2、4、8、12、16、2 0、2 4 ,测定Hb、RBC和血细胞比容 (HCT)观察疗效。结果 :①治疗贫血的总有效率达 89 6 % ,其中显效率 75 % ,Hb从治疗后wk 4起显著上升 (P =0 0 0 2 1) ;② 7例患者因Hb在wk 8达较高水平〔Hb(94 9± 16 9)g·L-1,HCT(2 8 2± 5 1) %〕 ,用药剂量维持在每 10～ 14d 1万U ,16wk后复查发现HCT仍维持在 (2 8 6± 3 8) % (P >0 0 5 ) ;③平均动脉压总体稳定 (从用药前 99 8mmHg至治疗 2 4wk时 10 1 9mmHg,P >0 0 5 )。 1例患者因头痛、BP上升而退出研究。结论 :r HuEPO 1万U ,qw ,能明显改善腹膜透析患者的贫血 ,使用安全。对于Hb已达较高水平的腹透患者可以选用更长间隔的给药方式     

大剂量重组人促红细胞生成素治疗血透患者肾性贫血的疗效与安全性

目的观察大剂量重组人促红细胞生成素(rHuEPO)治疗维持性血透患者肾性贫血的有效性和安全性.方法选择2002年2-8月期间在上海市24个血透中心的203例(男104例,女99例)血透肾性贫血患者,予rHuEPO 1万U,qw,sc,当Hb迅速升至100 g·L-1时可酌情减量至每2wk1次,甚至更少,观察20～24wk.共185例完成验证,按初始Hb(Hb0)分为A组(50g·L-1≤Hb0＜70 g·L-1),B组(70 g·L-1≤Hb0＜90g·L-1)和C组(Hb0≥90g·L-1);又按透析龄分为a组(＜3mo),b组(≥3mo,＜60mo)和c组(≥60mo).结果治疗后A,B和C组的Hb均有增加,各组的有效率分别为67.5%,85.7%和89.8%,平均有效率为81.6%;各透析龄组的Hb也有增加趋势.16例患者于wk4～12将rHuEPO减量为每2wk1次,Hb并无显著降低.验证过程中有16例患者发生22次药物不良事件,主要表现为高血压、头痛等,但与rHuEPO相关程度较低.结论大剂量rHuE-PO可有效纠正血透患者肾性贫血,且具有较高的安全性.     

早产儿注射促红细胞生成素对贫血的防治效果及护理

目的观察重组人类促红细胞生成素（recombinant human erythropoietin,rh—EPO）对早产儿贫血的防治效果。方法将早产后在我科住院的胎龄小于34周,体质量低于2000g的新生儿50例,按入院顺序随机分成两组,治疗组25例,对照组25例。两组患儿入院后常规给予保暖,维持体温、血糖、血压等内环境稳定,营养支持等处理,必要时输血。治疗组于生后第7天开始给予重组人类促红细胞生成素200IU／（kg·d）,皮下注射,每周3次,共4周。对照组仅用常规治疗。分别于生后第1、2、3、4、5周抽取外周静脉血,检测并比较不同时间两组早产儿的血红蛋白（haemoglobin,Hb）、网织红细胞（reticulocyte,Ret）和血细胞比容（hematocrit,HCT）。结果两组早产儿出生后血红蛋白均下降,但治疗组下降缓慢,治疗结束后两组差异非常显著（P〈0．01）;治疗组治疗后网织红细胞计数和血细胞比容较对照组明显升高（P〈0．01）;治疗结束后两组网织红细胞计数差异缩小（P〉0．05）,但血细胞比容差异仍显著（P〈0．01）;治疗组的输血率（8％）较对照组的输血率（32％）明显减少（P〈0．05）。结论重组人类促红细胞生成素可以有效的防治早产儿贫血,减少输血。     

溶瘤病毒类药物非临床安全性评价的实践与思考

在肿瘤基因治疗领域,具有自我复制、能选择性杀伤肿瘤细胞的溶瘤病毒已成为抗肿瘤治疗的有效武器之一。针对该类具有复制能力(条件复制性)的基因治疗产品,要按照基因治疗药物临床前评价思路,针对复制型病毒的特点,进行个性化的非临床安全性实验设计,除了一般生物制品的毒理学指标研究外,还要关注以病毒脱落为内容的水平传播,以及以生殖细胞系为内容的垂直传播研究。     

重组人促红细胞生成素在肿瘤相关性贫血中的应用

贫血是肿瘤患者的常见合并症, 既往治疗肿瘤相关性贫血多用输血,存在诸多缺点及风险.近年来重组人促红细胞生成素在肿瘤相关性贫血中的应用日益受到重视.现简述重组人促红细胞生成素的药物类别、适应证、用法用量、临床应用、缺点、不良反应、使用现状及应用限制等.     

Pharmacokinetics of recombinant human erythropoietin in chronic haemodialysis patients

Single dose intravenous and subcutaneous pharmacokinetics of recombinant human erythropoietin (rhEPO) has been determined in 6 chronic haemodialysis patients. Four patients, all on maintenance therapy with rhEPO, were consecutively treated both intravenously and subcutaneously with injections of rhEPO in a dose of 50 U/kg. Two previously untreated patients received 150 U/kg of rhEPO intravenously and subcutaneously. After intravenous injection of 50 U/kg of rhEPO a mean serum half-life value of 5.4 +/- 0.9 hr was found. The corresponding half-life after injection of 150 U/kg was 7.6 hr. The peak concentration of serum EPO after subcutaneous injection was 12.5-20 times lower than the corresponding intravenous Cmax. After administration of 150 U/kg subcutaneously the absorption of EPO was monitored to completion at 120 hr. The complete bioavailability of subcutaneous rhEPO after injection of 150 U/kg was 31.7%. Whether this low and protracted subcutaneous absorption of rhEPO is accounted for by either impeded absorption or partial skin degradation of rhEPO is not known.     

左卡尼汀联合重组人促红细胞生成素治疗肾性贫血

目的：观察左卡尼汀与重组人促红细胞生成素联合应用治疗肾性贫血患者临床疗效。方法：将62例尿毒症维持性血液透析中的肾性贫血患者随机分成治疗组及对照组,各31例,观察治疗3个月。两组患者都静脉注射重组人促红细胞生成素,每周100～150U/kg。治疗组于血液透析后静脉注射左卡尼汀1.0g,每周3次。结果：治疗组Hb、Hct提升水平显著高于对照组（P〈0.05）。结论：对血液透析的肾性贫血患者左卡尼汀能显著提高重组人促红细胞生成素的疗效。     

SDS-PAGE法测定重组人红细胞生成素糖基化程度

目的建立重组人红细胞生成素 (rhEPO)糖基化程度的测定方法。方法利用聚糖酶部分酶解rhEPO ,通过SDS PAGE电泳分离酶解片段 ,鉴定rhEPO的的糖基化程度。结果rhEPON 聚糖酶部分酶解的电泳图谱 ,可以明确指示N 连接糖基化程度。结论此法可以用于rhEPO的常规质量控制     

Clinical pharmacokinetics of epoetin (recombinant human erythropoietin)

Epoetin (recombinant human erythropoietin, EPO) is of proven benefit in the treatment of renal anaemia, and preliminary reports suggest that it may have a role in the management of other anaemic conditions. Pharmacokinetic and therapeutic studies have examined the use of epoetin administered intravenously, intraperitoneally and subcutaneously, and there is accumulating evidence that the last route has several advantages. After intravenous administration, epoetin is distributed in a volume comparable to the plasma volume, and plasma concentrations decay monoexponentially with a half-life of between 4 and 12 hours. Administration of epoetin in peritoneal dialysis fluid results in detectable concentrations in the bloodstream after 1 to 2 hours, and peak concentrations of the order of 2 to 4% of those obtained with the same intravenous dose are found after approximately 12 hours. The bioavailability of epoetin administered intraperitoneally in dialysis fluid is about 3 to 8%, but this may be increased by injecting the drug into a dry peritoneal cavity. Subcutaneous administration results in peak concentrations at about 18 hours which are 5 to 10% of those found after the same intravenous dose. The bioavailability of subcutaneous epoetin is about 20 to 30% and detectable serum concentrations are still present 4 days after administration, in contrast to intravenous administration after which concentrations have returned to baseline within 2 to 3 days. Remarkably little is known about the metabolic fate of either erythropoietin or epoetin. In addition, there is much controversy surrounding the relative roles of the kidney and liver in the catabolism of epoetin. About 3 to 10% of epoetin is excreted unchanged in the urine. In common with other glycoproteins, the carbohydrate residues which constitute 40% of its molecular size are essential for maintaining the stability of epoetin in circulation. Desialated epoetin, although biologically active in vitro, is cleared very rapidly from plasma with resultant loss of activity. Further work is required, however, in identifying the pathways of metabolism and elimination of this glycoprotein hormone.     

Pharmacokinetics and pharmacodynamics of recombinant human erythropoietin in rats

The pharmacokinetics and pharmacodynamics of recombinant human erythropoietin (rh-EPO; CAS for EPO: 11096-26-7) after repeated intravenous and subcutaneous administrations in rats were studied. Administration of rh-EPO by both routes caused significant increases in hematocrit. The pharmacokinetics of rh-EPO after intravenous and subcutaneous administration exhibited nonlinearity. The pharmacodynamics of rh-EPO was analyzed using the maximum effect (Emax) and sigmoid maximum effect (sigmoid Emax) models. Both models involved the assumption that rh-EPO in plasma would stimulate the proliferation of erythroid progenitor cells. Akaike's information criterion for the Emax model was lower than that for the sigmoid Emax model, suggesting that the Emax model might be an optimal model. The rh-EPO concentration at which the effect is half of the maximum was 0.383 ng/ml. This pharmacodynamic analysis suggests that the maintenance of effective plasma concentration might be important for the efficacy of rh-EPO.     

Comparative pharmacokinetics, safety, and tolerability after subcutaneous administration of recombinant human erythropoietin formulated with different stabilizers

This report summarizes the results of two double-blind, single-center, randomized studies that used a two-period crossover design. The objective of these two studies was to compare the safety, tolerability, pharmacokinetics, and pain score at the subcutaneous (sc) injection site of a phosphate-buffered recombinant human erythropoietin (EPREX, epoetin alfa, r-HuEPO) formulated with a new stabilizer (glycine and Polysorbate 80) with the commercially available EPREX formulations, which uses human serum albumin (HSA) as the stabilizer. Twenty-four healthy male volunteers were enrolled in each of the two studies. In the first study, subjects received a single 150 IU/kg sc dose of r-HuEPO using the 2000 IU/mL (2K) phosphate-buffered formulation with or without the new stabilizer (12 subjects/group). In the second study, subjects received a single 750 IU/kg sc dose of r-HuEPO using the 40 000 IU/mL (40K) phosphate-buffered formulation with or without the new stabilizer (12 subjects/group). In each study, r-HuEPO was administered over two separate dosing periods, each separated with a 28-day washout period. There were no significant differences in AUC and C(max) for either strength of r-HuEPO formulated with or without the new stabilizer, indicating that the absorption and disposition characteristics of the two formulations were similar after sc administration. Both r-HuEPO strengths with and without the new stabilizer were safe and well tolerated; the safety and tolerability profiles of both formulations for each r-HuEPO concentration were comparable. There were no statistically significant differences in pain score for either strength of r-HuEPO with and without the new stabilizer. It was concluded that the two phosphate-buffered r-HuEPO concentrations formulated with and without the new stabilizer are pharmacokinetically equivalent.     

Preclinical safety of recombinant human thrombin

Recombinant human thrombin (rhThrombin) is being developed as an alternative to thrombin products purified from pooled human or bovine plasma, which are currently marketed for topical hemostasis. Preclinical studies of rhThrombin were conducted prior to its evaluation as a topical adjunct to surgical hemostasis in clinical trials. No overt clinical pathology or signs were observed in cynomolgus monkeys following implantation of a gelatin sponge containing either rhThrombin or bovine thrombin to a surgical liver wound, and similar gross and microscopic wound healing characteristics were observed over an eight-week recovery period with either compound. Repeated subcutaneous injections of rhThrombin or bovine thrombin to cynomolgus monkeys produced no treatment-related effects. Whereas no monkeys demonstrated anti-rhThrombin antibody seroconversion, specific anti-bovine antibodies were detected in all tested monkeys exposed to bovine thrombin. Addition of rhThrombin or bovine thrombin to mouse fibroblast cells resulted in expected detachment and shape change. Topical application of rhThrombin to rabbits did not cause irritation to the eye, normal skin, or abraded skin. These studies showed that topical, subcutaneous, or implanted rhThrombin was minimally immunogenic, safe, and well tolerated in nonclinical models, and supported the clinical evaluation of rhThrombin in a variety of surgical settings.     

聚乙二醇修饰对重组人促红细胞生成素在大鼠体内药代动力学的影响

目的:研究聚乙二醇修饰对重组人促红细胞生成素在大鼠体内药代动力学的影响。方法:大鼠随机分成3组,分别单次皮下注射5μg·kg-1氨基葡萄糖-聚乙二醇-EPO(G-PEG-EPO)、甲氧基-聚乙二醇-EPO(M-PEG-EPO)和未经修饰的EPO原液后采集血样,采用酶联免疫吸附分析(ELISA)测定大鼠血浆样品中的EPO浓度。结果:给药后,与EPO相比,M-PEG-EPO,G-PEG-EPO较EPO吸收过程缓慢,峰浓度Cmax水平显著降低,代谢清除相对缓慢,末端消除相半衰期t1/2明显延长。而M-PEG-EPO,G-PEG-EPO的药代动力学参数除AUC0～inf和Cls外均无统计学差异。结论:聚乙二醇修饰能显著延长EPO在大鼠的末端消除相半衰期,G-PEG-EPO和M-PEG-EPO在大鼠的药代动力学性质相似。