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.     

恒河猴皮下注射聚乙二醇化重组粒细胞集落刺激因子的临床前安全性评价

目的:在恒河猴中进行皮下注射聚乙二醇化重组粒细胞集落刺激因子(PEG-G-CSF)的临床前安全性评价。方法:将恒河猴随机分为4组:对照组和低、中和高剂量PEG-G-CSF组,分别皮下注射溶媒或PEG-G-CSF(100,300和1 000μg.kg-1),每周给药1次,连续3个月,恢复期1个月。结果:各组动物的临床症状、体重、摄食量、体温、心电图和尿检各项指标均未见与给药相关的明显异常。给药组白细胞数量、分类白细胞比例出现与PEG-G-CSF药理学作用相关的明显改变。骨髓涂片镜检结果与血象改变基本一致。给药4周时,高剂量组动物血清中γ-谷氨酰转肽酶(GGT)、碱性磷酸酶(ALP)显著升高(P<0.01);PEG-G-CSF各给药组血清K+水平显著降低(P<0.01)。血液学及血清生化指标的改变在给药4周后均表现出逐渐恢复的趋势,恢复期未见明显异常。组织病理学检查发现PEG-G-CSF作用的靶器官为肝脏、脾脏和胸骨(骨髓)。给药3个月时,PEG-G-CSF各给药组抗体阳性的动物数分别为6/6,5/6,5/6。结论:恒河猴多次皮下注射PEG-G-CSF 300μg.kg-1可作为基本无毒反应剂量,100μg.kg-1为安全剂量。     

Preclinical safety evaluation of human gene therapy products

Human gene therapy products include naked DNA and viral as well as non- viral vectors containing nucleic acids. There is limited experience on the preclinical toxicity studies necessary for the safety evaluation of these products, which have been outlined in several recently released guidelines. Requirements for the preclinical safety evaluation of human gene therapy products are both specific and non-specific. All key preclinical studies should be performed in compliance with Good Laboratory Practices. Non-specific requirements are in fact common to all pharmaceutical products. Critical specific issues to be addressed are: the safety evaluation of the vector and the toxicity of the expressed protein(s), which are the two components of gene therapy products, the quality of the test article, the selection of animal species, and the verification that the administration method successfully transports the gene of interest, with the vector, to the target site(s). The treatment schedule should mimic the intended human therapeutic design. The host's immune response against the gene therapy product has to be evaluated to detect possible adverse effects and immune neutralization by antibodies. The biodistribution of the gene of interest is also essential and can be evaluated by molecular biology techniques, such as PCR. Specific confinement is required for the safe manipulation of viral vectors.      

传统中药王氏保赤丸的临床前毒理研究

王氏保赤丸是一个具有180多年应用历史的中药复方.本研究利用大鼠给药模型,对王氏保赤丸的临床前安全性进行了研究.在28天的给药实验期间,对SD大鼠进行每日1次的灌胃给药,对高、中、低剂量组而言,给药剂量分别为60 mg/kg/day、600 mg/kg/day和1500 mg/kg/day.给药结束后,进行15天的恢复...     

Preclinical safety evaluation of monoclonal antibodies

Monoclonal antibodies (mAbs) can be potent and specific therapeutics with long plasma half-lives and therefore long exposure times, which are now being clinically used to treat chronic disorders. Their recombinant design means some of their behaviours in the clinic can be determined at the design stage. However, their specific nature means a flexible approach often is required for preclinical studies and the use of novel approaches including parallel reagents and specific transgenic mice are being used. The key aspects at this level to consider are the effects on safety pharmacology and long-term immune status in the preclinical species used in order to predict to people the likely result of chronic clinical usage.     

Preclinical safety evaluation of monoclonal antibodies

Monoclonal antibodies (mAbs) are a well-established product class of biotechnology-derived pharmaceuticals for treating multiple diseases. A growing number of mAbs are being tested in clinical trials worldwide. Many of the second generation mAbs entering the clinic today are highly engineered, produced from recombinant cell lines, and present new safety challenges for regulators and industry scientists responsible for their safety evaluation. The increasing complexity of antibodies and the variety of recombinant production cell systems used for antibody manufacturing require a well thought-out approach for preclinical safety evaluation of mAbs. The focus of this chapter is to provide the reader with a basic framework for preparing a scientifically sound preclinical package for safety evaluation of therapeutic mAbs. We outline the general considerations for planning a preclinical program and the issues critical for success. We describe the types of preclinical safety studies and the timing for their conduct in relation to clinical trials. We also share some of the lessons learned about toxicity of mAbs from previous antibody development programs. A list of relevant regulatory documents issued by various government agencies and selected references to other useful texts and publications are also provided in the chapter. We believe that applying the principles described in this chapter will improve the quality and relevance of the preclinical safety data generated to support the future development of mAbs therapeutics.     

甘精胰岛素注射液的临床前安全性评价

目的 通过Beagle犬长期毒性试验及其伴随的免疫原性试验,观察甘精胰岛素注射液的毒性反应,确定未观察到临床不良反应的剂量水平（NOAEL）,为临床不良反应监测及防治提供参考。方法 健康Beagle犬40条,随机分为甘精胰岛素注射液低、中和高（0.5、1.0、2.0 IU/kg）剂量组、溶媒对照组及原研对照组（来得时,2.0 IU/kg）,每组8只动物,雌雄各半。连续sc给药30天,停药恢复16天。试验期间进行一般体征观察、进食量、体质量、肛温、全血血糖及心电图检查;测定血液学常规与凝血指标、血清生化、尿液常规等指标;进行骨髓细胞形态学检查、大体剖检检查以及组织病理学检查。采用间接ELISA法检测不同时期动物血清抗药的结合抗体;采用体外生物活性HPLC法检测产生抗药抗体的阳性血清的中和活性。结果 在给药期的第8和10天,原研对照组和高剂量组各有1只雌性动物在给药后5～6 h出现抽搐和流涎等由低血糖所致的异常症状,其中高剂量组的该异常动物于次日死亡;给药期第11天的心电图检查发现高剂量组的T波倒置比例略高于溶媒对照组（5/7 vs 1/8）,停药后恢复正常;其余存活动物的体质量、肛温、进食量、尿常规、血液学、血清生化和组织病理学等均未见毒理学意义的异常改变。免疫原性结果显示,仅有高剂量组1只雄性动物于给药期第12天产生抗药抗体,抗体滴度为1:16,阳性率为14.3%,产生结合抗体的血清样品经检测为非中和活性抗体。结论 在本试验条件下,Beagle犬sc重复给予甘精胰岛素注射液的NOAEL为1.0 IU/kg,该剂量相当于临床拟用剂量的2倍。该药在高剂量下可能对个别Beagle犬具有较弱的免疫原性。     

Preclinical safety evaluation of IFNalpha2a-NGR

IFNalpha2a-NGR is an antitumor agent of bacterial origin. The report presents the preclinical toxicity studies with IFNalpha2a-NGR in mice, rats and monkeys. The single-dose toxicity study showed no effect on general signs, body weight, food consumption, ophthalmology, hematology and clinical chemistry and necropsy analysis. In repeated-dose toxicity studies, increase in HB was noted both in rat and monkey, showed that IFNalpha2a-NGR may not cause the suppression of hematopoiesis. Decrease in AST, A/G, GLU, T-Bil in rat and AST, TP, GLO in monkey were noted, accompanied by increase in TP and GLB in rat and BUN in monkey. All the clinical chemistry changes were mild, reversible and considered to be incidental, since no related abnormal parameters or results were found. Increase in spleen and thymus organ-to-body weight ratios and decrease in menses were mild, reversible and likely related to pharmacology activity of IFNalpha2a. Ames, chromosomal aberration and bone marrow micronulecus test were conducted and the results were negative. The degree of irritation caused by various concentration of IFNalpha2a-NGR was determined to be the same as that induced by normal saline. In conclusion, preclinical safety studies that IFNalpha2a-NGR was well tolerated at pharmacologically active doses in mice, rats and monkeys.     

抗肿瘤新药临床前安全性评价

大多数药物均具有两重性,一方面能治疗疾病,另一方面又具有副反应,抗肿瘤药更是如此。因此,对新的抗肿瘤药物进行安全性评价就显得更加重要。为了更正确地评价抗肿瘤药物的安全性,特提出抗肿瘤药物临床前安全性评价的基本要求和抗肿瘤药物毒理学研究中需要讨论的一些问题。     

Preclinical safety evaluation of the benzodiazepine quazepam

7-Chloro-5-(2-fluorophenyl)-1,3-dihydro-1-(2,2,2-trifluoroethyl)-2H-1,4- benzodiazepine-2-thione (quazepam, Sch 16134, Dormalin) was evaluated for evidence of systemic toxicity, carcinogenicity and reproductive toxicity in several laboratory animal species including the hamster. Mutagenic potential was also assessed in one in vivo and three in vitro assays. In some studies, diazepam was used as a comparative control. Oral LD50 values were greater than 5000 mg/kg in the mouse and rat while i.p. LD50 values were approximately 900 and 2900 mg/kg in the mouse and rat, respectively. Studies in hamsters for 4 weeks at doses up to 500 mg/kg/d and for 51 weeks at doses up to 120 mg/kg/d demonstrated that the liver was the principal target organ in this species with the effects upon the liver related to dose and duration of dosing. Studies in the squirrel monkey for 13 and 52 weeks at doses up to 50 mg/kg/d demonstrated a transient ataxia, hypoactivity and somnolence during the initial two weeks of dosing. No unusual necropsy or microscopic observations were noted in the 13-week study. Male reproductive organs of quazepam-dosed monkeys were reduced in weight after 52 weeks. Moderate to marked impairment of spermatogenesis and higher liver weights with moderate to marked fatty change in both sexes were observed in groups given diazepam. Abrupt withdrawal of quazepam or diazepam after 52 weeks of dosing was associated at all dose levels with excitability, hyperactivity and convulsions. Two quazepam- and all diazepam-dosed monkeys died.(ABSTRACT TRUNCATED AT 250 WORDS)     

Preclinical safety evaluation of intravenously administered mixed micelles

Mixed micelles, with their main constituents lecithin and glycocholic acid, form a new principle for the parenteral administration of compounds which are poorly water-soluble. Their composition of mainly physiological substances as well as their comparatively good stability substantiate their attractivity in comparison to existing solvents. A decomposition due to physical influences such as heat or storage for several years will almost exclusively affect the lecithin component in the form of hydrolysis into free fatty acids and lysolecithin. Their toxicity was examined experimentally in various studies using both undecomposed and artificially decomposed mixed micelles. In these studies the mixed micelles were locally and systemically well tolerated and proved to be neither embryotoxic, teratogenic nor mutagenic. Only when comparatively high doses of the undecomposed mixed micelles were administered, corresponding to approximately 30 to 50 times the anticipated clinical injection volume (of e.g. diazepam mixed micelles), did some vomitus (dogs), slight liver enzyme elevation (rats and dogs), and slightly increased liver weights (dogs) occur. After repeated injections of the artificially decomposed formulation (approximately 25% of lecithin hydrolyzed to free fatty acids and lysolecithin) effects such as intravascular haemolysis, liver enzyme elevations and intrahepatic cholestasis (dogs only) were observed but only when doses exceeding a threshold of approximately 40 to 60 mg lysolecithin/kg body weight were administered. All alterations were reversible after cessation of treatment.     

Preclinical safety testing of species-specific proteins produced with recombinant DNA-technqiues

Summary Preclinical toxicity studies in animals with species-specific recombinant DNA products have now been performed for several years. An interim statement on the significance of these animal tests and their ability to predict adverse effects in humans therefore appears indicated, with the aim of deducing future testing strategies. The experience accumulated so far shows that the animal models have failed to predict adverse effects subsequently observed in man. Immunogenicity of these proteins further restricted the usefulness of standard toxicity tests. There is also increasing evidence that animal tests on the toxic potential of impurities contained in the products are markedly inferior in sensitivity to analytical and quality control methods.Thus, modified testing programs are proposed to demonstrate safety rather than target organ toxicity using rodents and small non-rodent species and restricted dosing; furthermore the study duration should be limited by the detection of immunogenic responses.Working Group Participants: K. Hoffmann, G. Schlueter, H. D. Schlumberger, E.-A. Loebbecke, Bayer AG; H. Ronneberger, Behringwerke AG; H. Stoetzer, Boehringer Ingelheim KG; R. Ziel, P. Graepel, Ciba-Geigy AG; H. H. Donaubauer, D. Mayer, Hoechst AG; K. Teelmann, E. Theiss, F. Hoffmann-La Roche & Co AG; R. Omilian-Rosso, B. Ryffel, Sandoz AG; Ch. Hohbach, H. Lehmann, M. Baumeister, L. Luetzen, Thomae GmbH     

增殖诱导配体-siRNA/类脂质体复合体的临床前安全性评价

目的考察增殖诱导配体(APRIL)-小干扰RNA(siRNA)/类脂质体复合物的毒性。方法①小鼠iv给予APRIL-siRNA/类脂质体复合物500 mg·kg-1,连续14 d称量小鼠体质量及观察死亡情况;②每只豚鼠分别于第0,7和14天左侧涂抹0.2 ml APRIL-siRNA/类脂质体复合物130 g.L-1,2,4-二硝基氯代苯10 g.L-1(阳性对照),末次接触后14 d,将各受试物0.2 ml涂于右侧,持续6 h,观察24和48 h皮肤致敏情况;③小鼠分别iv给予APRIL-siRNA/类脂质体复合物125,250和500 mg·kg-1、环磷酰胺40 mg·kg-1(阳性对照)组。间隔24 h,第2次注射后6 h处死小鼠,检测小鼠骨髓嗜多染红细胞微核率;④小鼠分别iv给予APRIL-siRNA/类脂质体复合物125,250和500 mg·kg-1、环磷酰胺(阳性对照),每天1次,连续5 d,检测小鼠精子畸形率。结果与正常对照组相比,APRIL-siRNA/类脂质体复合物500 mg·kg-1组小鼠体质量和各组织无明显变化,没有小鼠死亡,未表现急性中毒现象。APRIL-siRNA/类脂质体脂质体复合物对豚鼠皮肤无致敏性。该脂质体复合物125,250和500 mg·kg-1组小鼠骨髓嗜多染红细胞微核率分别为(1.8±1.0)‰,(1.6±0.9)‰和(2.4±1.1)‰;精子畸形率分别为(1.98±0.27)%,(1.96±0.15)%和(2.04±0.16)%,与对照组微核率(2.2±1.3)‰和精子畸形率(1.96±0.29)%无明显差异。结论在本实验剂量范围内,APRIL-siRNA/类脂质体复合物对小鼠无明显毒性。     

重组人白细胞介素10对角朊细胞增殖及产生细胞因子的影响

目的：研究重组人白细胞介素10(rhIL-10)对无血清培养的角朊细胞增殖和产生细胞因子的影响，探讨其治疗银屑病的作用机制。方法：用四甲基偶氮唑蓝比色法(MTT)测定其对细胞增殖的影响；小鼠胸腺细胞增殖法检测白细胞介素1(IL-1)；ELISA法检测白细胞介素6(IL-6)、白细胞介素8(IL-8)。结果：重组人白细胞介素10抑制角朊细胞增殖与IL-1、IL-6及IL-8的分泌，并呈剂量依赖关系。结论：重组人白细胞介素10抑制角朊细胞与细胞因子分泌，可能是治疗银屑病的作用机理之一．     

重组携带hIL-10基因的腺病毒载体的构建与鉴定

目的 构建携带人白细胞介素10(hIL-10)基因的腺病毒载体,体外细胞学鉴定其介导的基因表达.方法 以pORF-hIL10质粒为模板,PCR扩增hIL-10基因,获得hIL10 cDNA片段,酶切并插入线性化pUC19质粒,命名为pUC19-hIL10.再酶切pUC19-hIL10,插入pDC315-EGFP,置换EGFP序列,构建pDC315-hIL10.将质粒pDC315-hIL10和pDC315-EGFP分别共转染至293细胞,产生复制缺陷型重组腺病毒.pDC315-hIL10和pDC315-EGFP分别感染大鼠肝细胞,免疫学方法鉴定目的基因的表达.结果 经PCR扩增、鉴定,证明已正确构建重组腺病毒Ad5-hIL10和Ad5-EGFP.pDC315-EGFP能够在大鼠肝细胞介导EGFP的表达,使细胞呈绿色荧光反应;pDC315-hIL10能够在大鼠肝细胞介导hIL-10的表达.结论 成功构建了重组腺病毒质粒Ad5-hIL10和Ad5-EGFP,可用于IL-10基因对肝细胞损伤的保护作用的进一步研究.     

重组人白介素-10对大鼠血管平滑肌细胞增殖和细胞周期的影响

目的　观察重组人白介素 10 (rhIL 10 )分别对肿瘤坏死因子 (TNF α)和血小板源性生长因子 (PDGF BB)刺激下离体大鼠胸主动脉血管平滑肌细胞增殖和细胞周期的影响。方法　体外培养大鼠胸主动脉血管平滑肌细胞 ,采用MTS/PES法确定血管平滑肌细胞的增殖状态 ,应用流式细胞术测定细胞周期。结果　与对照组相比 ,肿瘤坏死因子和血小板源性生长因子均对血管平滑肌细胞增殖具有明显的刺激作用 (P <0 0 5 )。rhIL 10单独应用对血管平滑肌细胞生长没有影响 (P >0 0 5 )。在TNF α和血小板源性生长因子分别刺激下 ,rhIL 10均可抑制血管平滑肌细胞的生长(P <0 0 5 )。流式细胞术测定的结果显示rhIL 10分别可以使TNF α和PDGF BB作用下的VSMCs大部分处于G0 /G1期 ,与对照组相比差异有显著性 (P <0 0 1)。结论　重组人白介素 10可抑制细胞因子和生长因子诱导的血管平滑肌细胞增殖     

Preclinical safety evaluation of inhaled cyclosporine in propylene glycol.

Cyclosporine inhalation solution has the potential to improve outcomes following lung transplantation by delivering high concentrations of an immunosuppressant directly to the allograft while minimizing systemic drug exposure and associated toxicity. The objective of these studies was to evaluate the potential toxicity of aerosolized cyclosporine formulated in propylene glycol when given by inhalation route to rats and dogs for 28 days. Sprague-Dawley rats received total inhaled doses of 0 (air), 0 (vehicle, propylene glycol), 7.4, 24.3, and 53.9 mg cyclosporine/kg/day. In a separate study, beagle dogs were exposed to 0, 4.4, 7.7, and 9.7 mg cyclosporine/kg/day. Endpoints used to evaluate potential toxicity of inhaled cyclosporine were clinical observations, body weight, food consumption, respiratory functions, toxicokinetics, and clinical/anatomic pathology. Daily administration of aerosolized cyclosporine did not result in observable accumulation of cyclosporine in blood or lung tissue. Toxicokinetic analysis from the rat study showed that the exposure of cyclosporine was approximately 18 times higher in the lung tissue compared to the blood. Systemic effects were consistent with those known for cyclosporine. There was no unexpected systemic toxicity or clinically limiting local respiratory toxicity associated with inhalation exposure to cyclosporine inhalation solution at exposures up to 2.7 times the maximum human exposure in either rats or dogs. There were no respiratory or systemic effects of high doses of propylene glycol relative to air controls. These preclinical studies demonstrate the safety of aerosolized cyclosporine in propylene glycol and support its continued clinical investigation in patients undergoing allogeneic lung transplantation.     

Disposition of recombinant human interleukin-10 in subjects with various degrees of renal function.

The pharmacokinetics of intravenously administered recombinant human interleukin-10 (rHuIL-10) were evaluated in 18 subjects with creatinine clearances (Clcr) between 2.7 and 116.7 mL/min/1.73 m2. Serum samples for rHuIL-10 were obtained over a 48-hour period after a single 25 micrograms/kg i.v. bolus infusion. AUC, total body clearance (Clp), and steady-state volume of distribution (Vdss) were derived by compartmental methods. Analysis of serum concentrations showed statistically significant group differences for log-transformed AUC and original scale Clp (p < 0.01). The AUC and effective half-life increased, while the mean Clp of rHuIL-10 decreased as renal function declined. A linear relationship between AUC and Clcr as well as Clp and Clcr demonstrates that the disposition of rHuIL-10 is altered in subjects with renal insufficiency. No serious adverse events were noted.