Current status and future of target-based therapeutics

With the beginning of the 21st century, a new and exciting era for cancer therapy has begun with the appearance of molecular targeted drugs. Numerous drugs for chemotherapy have been discovered following careful screening of natural and synthetic components. After screening, candidate chemotherapy drugs are examined to determine if they have sufficiently cytotoxic to function as an anti-tumor therapeutic. However, the development of molecular targeted drugs is based on more logical methodologies. First, the target is determined then a search is conducted for molecules able to inhibit the target molecule. Some molecular targeting drugs, such as Glivec (Imatinib, STI571), have shown amazing effects when compared to currently used chemotherapy drugs, whereas few others have completely failed to inhibit tumor development in clinical trials. Thus, an efficient method for finding effective molecular targeted drugs is needed. An important question is whether the target molecule is responsible for tumor growth or metastasis. In addition, the clinical administration schedule must be suitable for the component used. The drugs will not be completely successful in clinical trials if any of the key points are overlooked. Translational studies are necessary for a complete evaluation of molecular targeted drugs and, based on the results observed in clinical applications, the testers must return to their basic laboratory if necessary and improve the drugs for more advanced therapy. In this review we discuss on the current and future status of molecular target drugs.     

嵌合抗原受体T细胞免疫疗法在B细胞非霍奇金淋巴瘤中的研究进展

摘要：非霍奇金淋巴瘤（NHL）是最常见的血液系统恶性肿瘤,复发难治患者预后欠佳。嵌合抗原受体T细胞免疫疗法（CAR-T）是近年来新兴的免疫治疗方法,在恶性肿瘤尤其是血液系统恶性肿瘤治疗方面取得了较多突破,尤其是给复发难治的B细胞NHL患者带来了希望。目前,美国食品药品监督管理局（FDA）已批准两款CAR-T细胞疗法tisagenlecleucel和axicabtagene ciloleucel,其他几种产品仍在临床试验中。本文就CAR-T的结构及其在常见B细胞NHL中的疗效、安全性及研究趋势做一综述。     

Consequences of double negative regulatory T cell and antigen presenting cell interaction on immune response suppression

Recent studies have indicated that regulatory T cell (Treg)-mediated suppression may depend on interactions with antigen presenting cells (APCs). TCRαβ(+)CD3(+)CD4(-)CD8(-)NK1.1(-) double-negative (DN) Tregs have been shown to be able to suppress effector T cells in vitro in mice and humans, and control various diseases in an antigen (Ag)-specific manner in murine models. Studies on DN Tregs have been focused on their suppressive effect on T cells. However, the nature of APCs that can effectively activate DN Tregs as well as the effect of DN Tregs on APCs, have not previously been studied. In this report, we investigated the interactions of DN Tregs with APCs. We found that although stimulation with na?ve allogeneic APCs could activate DN Tregs, it failed to induce proliferation of DN Tregs. Interestingly, stimulation with LPS-activated allogeneic APCs significantly augmented the proliferation of DN Tregs compared to na?ve allogeneic APCs. Importantly, the expanded DN Tregs can maintain their suppressive function. Further, DN Tregs proliferated in the presence of LPS-activated B cells in an Ag-specific fashion. Although DN Tregs were not able to down regulate the expression of CD80 or CD86 on LPS-activated B cells, they could kill activated allogeneic as well as syngeneic B cells via a perforin-dependent pathway, indicating that eliminating activated B cells may contribute to DN Treg-mediated suppression. These data provide important insights into the interactions of DN Tregs with APCs and may facilitate production of functional Ag-specific DN Tregs in a clinical setting.     

嵌合抗原受体T细胞治疗恶性肿瘤的研究进展

以嵌合抗原受体为基础的细胞免疫治疗已成为治疗恶性肿瘤的一种新策略。其主要特点是通过基因修饰获得携带识别肿瘤抗原特异性受体T细胞并赋予T细胞靶向杀伤活性的个性化治疗方法。与传统的T细胞免疫疗法相比,嵌合抗原受体可以通过增加共刺激分子信号从而增强T细胞抗肿瘤的杀伤性,并可克服肿瘤局部免疫抑制微环境和打破宿主免疫耐受状态,随着转化医学研究的不断深入,基于嵌合抗原受体的免疫治疗新策略会给肿瘤患者带来新的希望。     

肿瘤治疗的新途径：嵌合抗原受体T细胞疗法

免疫疗法已经成为癌症治疗中的重要手段。使用嵌合抗原受体（chimeric antigen receptor,CAR）修饰的T细胞治疗癌症因其显著的疗效成为了癌症治疗研究的新方向。CAR包含抗原结合部分、铰链区、跨膜结构域以及结合活化T细胞的细胞共刺激结构。对目标肿瘤的特异性清除是通过CAR-T细胞对抗原的特异性选择和共刺激信号转导,CAR-T细胞在过继后的转运、维持,以及抗肿瘤功能的保留实现的。此文对目前基于CAR-T细胞疗法的基本原理及临床应用作一阐述。     

Clinical translation of theranostic radiopharmaceuticals: Current regulatory status and recent examples

With the development of ever more radiopharmaceuticals suitable for theranostic applications, translation of novel compounds from the preclinical stage towards clinical application becomes a bottleneck for the advances in Nuclear Medicine. This review article summarizes the current regulatory framework for clinical trials with radiopharmaceuticals in the European Union, provides a general overview of the documentation required, and addresses quality, safety, and clinical aspects to be considered. By using a recent successful example of translating a theranostic peptide radioligand, namely ¹¹¹In‐CP04, which targets receptors expressed in medullary thyroid carcinoma, the pathway from the preclinical development over establishing the required pharmaceutical documentation to designing and submitting a clinical trial is reviewed. Details regarding preclinical data, generation of the documentation, and final successful application are described. This article should provide an insight in an ever more complex process to bring innovations in the field of radiopharmaceuticals into patients.     

嵌合抗原受体修饰的T细胞治疗致细胞因子释放综合征2例

目的 观察嵌合抗原受体修饰的T细胞(CAR-T细胞)治疗复发难治性B细胞血液病的不良反应,探讨细胞因子释放综合征(Cytokine-Release Syndrome CRS)有效的护理措施。方法 对2例复发难治急性B细胞白血病病人应用靶向CD19的CAR-T细胞治疗时因细胞因子释放引起的一系列不良反应、治疗和护理措施进行观察及统计。结果 2例病人在接受CAR-T细胞治疗并出现细胞因子释放综合征后,经过严密的生命体征监测,积极的治疗,全方位的生活护理和心理护理,病人症状均缓解,且白血病经骨髓细胞学检查提示完全缓解。结论 细胞因子释放综合征是CAR-T治疗中最严重并发症之一,经过临床积极干预和护理后可获得良好效果。     

嵌合抗原受体修饰T细胞治疗前列腺癌的研究进展

摘要：嵌合抗原受体修饰T细胞（CAR-T）是近年来免疫治疗的热点,在血液系统疾病的治疗中取得了显著的临床疗效。目前,CAR-T在前列腺癌（PCa）治疗的研究中也取得了较大进展,其中以前列腺特异性膜抗原（PSMA）和前列腺干细胞抗原（PSCA）为靶点的CAR-T治疗进展较快,其可显著抑制肿瘤细胞生长,一定程度地延缓疾病进展。本文综述了前列腺肿瘤相关抗原（TAA）在前列腺癌CAR-T治疗中的最新研究进展,并对CAR-T在前列腺癌治疗中的挑战予以简要探讨,以期为临床提供参考。     

靶向CD123嵌合抗原受体T细胞治疗急性髓系白血病最新进展

急性髓系白血病(acute myeloid leukemia,AML)是最常见的、死亡率最高的一类白血病。在过去的40年里,尽管人们对于AML的认识更加深入,但是与其他血液肿瘤相比,AML的治疗并没有明显的变化。CD123是AML相关抗原,高表达于白血病干细胞,低或不表达于正常造血干细胞。作为治疗AML的潜在治疗靶点,近期靶向CD123+细胞免疫治疗技术已经有了新的进展,尤其是嵌合抗原受体(chimeric antigen receptor,CAR)T细胞治疗技术发展迅速。早期研究也已经证实CD123 CAR-T细胞具有抗白血病效应,而且对正常造血系统有不同程度的影响,这也为临床治疗复发/难治AML提供了新的思路。     

Testing considerations for novel cell substrates: a regulatory perspective

The development of new products for the prevention and treatment of current as well as emerging and re-emerging diseases has led to the introduction of novel cell substrates in biologics. Examples include the demand for large-scale production of pandemic influenza vaccines and for therapeutic proteins, and the use of novel vectors for AIDS vaccines and in cancer gene therapy. A major safety issue regarding the use of novel cell substrates is adventitious agents, including viruses that may have been exogenously introduced due to cell passage history or indigenous viruses that are naturally occurring in the species of cell origin due to infection, or endogenous retroviruses that exist as a normal part of the host cell DNA. Additionally, in the case of genetically engineered cells, there is a concern for recombinant viruses that may be generated de novo involving vector virus sequences. Furthermore, potential oncogenicity of residual cellular DNA remains a theoretical safety concern related to tumorigenic cell substrates. This paper discusses safety issues related to novel cell substrates with a focus on tumorigenic cells and genetically engineered cells and presents the current testing recommendations for general cell substrate safety with details on additional assays for consideration in testing some novel cell substrates including tumorigenic cells.     

靶向CD19嵌合抗原受体T细胞体外构建、扩增及抗肿瘤活性研究

目的  探索特异性靶向CD19的嵌合抗原受体（chimeric antigen receptor, CAR）T细胞的构建与制备方法,并研究其体外杀伤靶细胞的效果。方法  通过基因合成和分子克隆手段构建anti-CD19-CAR片段并将其插入plenti6.3慢病毒载体,利用293FT悬浮细胞系包装慢病毒并转染人外周血单个核细胞来源的CD3⁺ T细胞,通过流式细胞术鉴定转染效率,并通过实时无标记细胞分析法和细胞计数试剂盒8检测anti-CD19-CAR-T细胞体外杀伤效果。结果  获得了表达抗CD19的单链抗体基因的慢病毒,病毒滴度可达3.2×10⁸ 噬斑形成单位/ml。经慢病毒转染的CD3⁺ T细胞在体外培养14 d后,细胞扩增效率达(60.2±11.5)倍,anti-CD19-CAR-T细胞阳性率达90.57%。经检测,anti-CD19-CAR-T细胞均可有效杀伤CD19⁺靶细胞。结论  建立了基于无血清悬浮细胞系的anti-CD19-CAR慢病毒包装系统,成功构建靶向CD19抗原的CAR-T细胞,能特异性杀伤CD19+肿瘤细胞。     

Current status of prediction of drug disposition and toxicity in humans using chimeric mice with humanized liver

Abstract

1.?Human-chimeric mice with humanized liver have been constructed by transplantation of human hepatocytes into several types of mice having genetic modifications that injure endogenous liver cells. Here, we focus on liver urokinase-type plasminogen activator-transgenic severe combined immunodeficiency (uPA/SCID) mice, which are the most widely used human-chimeric mice. Studies so far indicate that drug metabolism, drug transport, pharmacological effects and toxicological action in these mice are broadly similar to those in humans.

2.?Expression of various drug-metabolizing enzymes is known to be different between humans and rodents. However, the expression pattern of cytochrome P450, aldehyde oxidase and phase II enzymes in the liver of human-chimeric mice resembles that in humans, not that in the host mice.

3.?Metabolism of various drugs, including S-warfarin, zaleplon, ibuprofen, naproxen, coumarin, troglitazone and midazolam, in human-chimeric mice is mediated by human drug-metabolizing enzymes, not by host mouse enzymes, and thus resembles that in humans.

4.?Pharmacological and toxicological effects of various drugs in human-chimeric mice are also similar to those in humans.

5.?The current consensus is that chimeric mice with humanized liver are useful to predict drug metabolism catalyzed by cytochrome P450, aldehyde oxidase and phase II enzymes in humans in vivo and in vitro. Some remaining issues are discussed in this review.     

Current status of immunotherapy in B cell malignancies

Conventional treatment of hematologic malignancies mainly consists of chemotherapeutic agents or a combination of both, chemotherapy and monoclonal antibodies. Despite recent advances, chemotherapeutic treatments often remain unsatisfying due to severe side effects and incomplete long-term remission. Therefore the evaluation of novel therapeutic options is of great interest. B cell malignancies, in particularly follicular lymphomas, chronic lymphocytic leukemia and multiple myeloma, represent the most immune-responsive types of all human cancer. Several immunotherapeutic strategies are presently employed to combat these B-cell malignancies. Active immunotherapies include vaccination strategies with dendritic cells (DCs) and genetically-modified tumor cell preparations as well as DNA and protein vaccination. Most of these vaccines target the tumor-specific immunoglobulin idiotype and have already demonstrated some anti-lymphoma activity in early phase clinical trials while their definitive impact is evaluated in ongoing phase III randomized trials. In contrast to these active immunizations, T cells transduced with chimeric antigen receptors and donor leukocyte infusions (DLI) represent adoptive (passive) immunotherapies. Recent advances of gene transduction technologies enabled improvement of immunotherapeutic strategies based on genetic modification of malignant cells or adoptive T cells. Current early phase clinical trials are investigating the potential of these innovative approaches. At the moment it remains unclear if the novel immunotherapeutic strategies will be able to play a similar role in the treatment of B cell malignancies than the already established antibody-based immunotherapy.     

Anti-tumour effect of the fourth-generation chimeric antigen receptor T cells targeting CD133 against cholangiocarcinoma cells

Current treatment of cholangiocarcinoma (CCA) – a lethal bile duct cancer – is ineffective because the disease is usually diagnosed at late and advanced stage. Thus, a novel therapeutic modality is urgently required. Fourth-generation chimeric antigen receptor (CAR4) T cells was created to target CD133, a well-known cancer stem cell marker, that is highly expressed and associates with cancer progression. The anti-CD133-CAR4 T cells showed high efficacy against CD133-expressing CCA cells. Tumour cell lysis occurred in a dose- and CD133 antigen-dependent manner, and significantly higher, up to 57.59% ± 9.62 at effector to target ratio of 5:1 in a CCA cell line – KKU-213A cells, compared to mock control (p = 0.008). Similarly, significant IFN-γ (p = 0.011) and TNF-α (p = 0.002) upregulation was observed upon tumour treatment. The effectiveness of our anti-CD133-CAR4 T cells will be beneficial not only for CD133-expressing CCA, but also for other CD133-expressing tumours. This study may guide future in vivo study and clinical trials.     

嵌合抗原受体 T 细胞治疗原发性肿瘤的优势与研究进展

嵌合抗原受体 （Car） T 细胞因不仅具有较强特异性识别肿瘤抗原的特性, 还具有杀伤性、 亲和力高等优点, 因而受到较多的关注。尽管其在抗肿瘤方面发挥了很多优势, 但是仍存在不足之处, 需要进一步优化来提高其临床 应用的安全性。本研究对 Car T 细胞结构及其生物功能、 治疗流程、 应用进展以及应用风险进行综述, 为进一步在临 床开展 Car T 免疫治疗提供参考。