Points to Consider when Establishing Drug Product Specifications for Parenteral Microspheres

Drug product specifications are a critical element of a good control strategy. Parenteral microsphere products are complex dosage forms, requiring careful development of test methods and acceptance criteria for the specifications. In particular, the in vitro release test method and acceptance criteria require rigorous scientific consideration and should be developed with an eye toward understanding the mechanisms of drug release. The final specifications need to ensure the safety, identity, strength, performance, and quality of the drug product at release and during storage through the end of its shelf-life. The specification limits are typically established based upon regulatory guidance, available data from the manufacturing process (process capability), from non-clinical, clinical, and stability studies.     

Strategies for Setting Patient-Centric Commercial Specifications for Biotherapeutic Products

Commercial specifications for a new biotherapeutic product are a critical component of the product's overall control strategy that ensures safety and efficacy. This paper describes strategies for setting commercial specifications as proposed by a consortium of industry development scientists. The specifications for some attributes are guided by compendia and regulatory guidance. For other product quality attributes (PQAs), product knowledge and the understanding of attribute criticality built throughout product development should drive specification setting. The foundation of PQA knowledge is an understanding of potential patient impact through an assessment of potency, PK, immunogenicity and safety. In addition to PQA knowledge, the ability of the manufacturing process to consistently meet specifications, typically assessed through statistical analyses, is an important consideration in the specification-setting process. Setting acceptance criteria that are unnecessarily narrow can impact the ability to supply product or prohibit consideration of future convenient dosage forms. Patient-centric specifications enable appropriate control over higher risk PQAs to ensure product quality for the patient, and flexibility for lower risk PQAs for a sustainable supply chain. This paper captures common strategic approaches for setting specifications for standard biotherapeutic products such as monoclonal antibodies and includes considerations for ensuring specifications are patient centric.     

治疗性单克隆抗体类药物分析技术及其应用

治疗性单克隆抗体(单抗)类药物是高度均一的生物大分子,抗原表位、理化性质和生物活性等方面的均一性程度高,能够通过特异性地与靶标分子结合发挥治疗作用。单抗类药物治疗过程中不良反应发生率低、患者耐受性高。单抗类药物是生物药物领域的热点和焦点,已成为现代生物制药行业中占比最大、增长最快的细分领域。根据生产技术和工艺的不同,单抗类药物发展已经经历了4代。我国最近批准上市的信迪利单抗注射液、特瑞普利单抗注射液、注射用卡瑞利珠单抗和替雷利珠单抗注射液等均属于第3代人源化单克隆抗体药物。单抗类药物分子结构复杂,容易发生二聚体、多聚体、末端氨基酸突变等不均一性变化,严重影响临床用药的安全性和有效性。对单抗类药物的原液和成品进行有效的质量控制是确保该类产品安全性和有效性的重要措施。目前,单抗类产品质量控制与分析的主要方法包括高效液相色谱(HPLC)法、酶联免疫吸附测定(ELISA)法、毛细管区带电泳(CZE)法、毛细管等电聚焦电泳(cIEF)法、成像毛细管等电聚焦电泳(iCIEF)法和十二烷基硫酸钠-毛细管电泳(CE-SDS)法等。本文就单抗类药物质量控制分析方法及应用进行综述,为相关研究及产品质量控制提供参考。     

Statistical Considerations in Setting Product Specifications

According to ICH Q6A (1999), a specification is defined as a list of tests, references to analytical procedures, and appropriate acceptance criteria, which are numerical limits, ranges, or other criteria for the tests described. For drug products, specifications usually consist of test methods and acceptance criteria for assay, impurities, pH, dissolution, moisture, and microbial limits, depending on the dosage forms. They are usually proposed by the manufacturers and subject to the regulatory approval for use. When the acceptance criteria in product specifications cannot be pre-defined based on prior knowledge, the conventional approach is to use data from a limited number of clinical batches during the clinical development phases. Often in time, such acceptance criterion is set as an interval bounded by the sample mean plus and minus two to four standard deviations. This interval may be revised with the accumulated data collected from released batches after drug approval. In this article, we describe and discuss the statistical issues of commonly used approaches in setting or revising specifications (usually tighten the limits), including reference interval, (Min, Max) method, tolerance interval, and confidence limit of percentiles. We also compare their performance in terms of the interval width and the intended coverage. Based on our study results and review experiences, we make some recommendations on how to select the appropriate statistical methods in setting product specifications to better ensure the product quality.     

FIP Guidelines for Dissolution Testing of Solid Oral Products

Dissolution testing is an important physiochemical test for the development of solid oral dosage forms, tablets, and capsules. As a quality control test, the dissolution test is used for assessment of drug product quality and is specified for batch release and regulatory stability studies. In vitro dissolution test results can often be correlated with the biopharmaceutical behavior of a product.This article provides a summary of views from major global agencies (Europe, Japan, United States), pharmacopoeias, academia, and industry. Based on available guidance and literature, this article summarizes highlights for development and validation of a suitable dissolution method, setting appropriate specifications, in vitro–in vivo comparison, and how to obtain a biowaiver.     

An Intercompany Perspective on Biopharmaceutical Drug Product Robustness Studies

The Biophorum Development Group (BPDG) is an industry-wide consortium enabling networking and sharing of best practices for the development of biopharmaceuticals. To gain a better understanding of current industry approaches for establishing biopharmaceutical drug product (DP) robustness, the BPDG-Formulation Point Share group conducted an intercompany collaboration exercise, which included a bench-marking survey and extensive group discussions around the scope, design, and execution of robustness studies. The results of this industry collaboration revealed several key common themes: (1) overall DP robustness is defined by both the formulation and the manufacturing process robustness; (2) robustness integrates the principles of quality by design (QbD); (3) DP robustness is an important factor in setting critical quality attribute control strategies and commercial specifications; (4) most companies employ robustness studies, along with prior knowledge, risk assessments, and statistics, to develop the DP design space; (5) studies are tailored to commercial development needs and the practices of each company. Three case studies further illustrate how a robustness study design for a biopharmaceutical DP balances experimental complexity, statistical power, scientific understanding, and risk assessment to provide the desired product and process knowledge. The BPDG-Formulation Point Share discusses identified industry challenges with regard to biopharmaceutical DP robustness and presents some recommendations for best practices.     

Prediction of the Hydrogen Peroxide–Induced Methionine Oxidation Propensity in Monoclonal Antibodies

Methionine oxidation in therapeutic antibodies can impact the product's stability, clinical efficacy, and safety and hence it is desirable to address the methionine oxidation liability during antibody discovery and development phase. Although the current experimental approaches can identify the oxidation-labile methionine residues, their application is limited mostly to the development phase. We demonstrate an in silico method that can be used to predict oxidation-labile residues based solely on the antibody sequence and structure information. Since antibody sequence information is available in the discovery phase, the in silico method can be applied very early on to identify the oxidation-labile methionine residues and subsequently address the oxidation liability. We believe that the in silico method for methionine oxidation liability assessment can aid in antibody discovery and development phase to address the liability in a more rational way.     

Japan-Specific Key Regulatory Aspects for Development of New Biopharmaceutical Drug Products

Japan represents the third largest pharmaceutical market in the world. Developing a new biopharmaceutical drug product for the Japanese market is a top business priority for global pharmaceutical companies while aligning with ethical drivers to treat more patients in need. Understanding Japan-specific key regulatory requirements is essential to achieve successful approvals. Understanding the full context of Japan-specific regulatory requirements/expectations is challenging to global pharmaceutical companies due to differences in language and culture. This article summarizes key Japan-specific regulatory aspects/requirements/expectations applicable to new drug development, approval, and postapproval phases. Formulation excipients should meet Japan compendial requirements with respect to the type of excipient, excipient grade, and excipient concentration. Preclinical safety assessments needed to support clinical phases I, II, and III development are summarized. Japanese regulatory authorities have taken appropriate steps to consider foreign clinical data, thereby enabling accelerated drug development and approval in Japan. Other important topics summarized in this article include: Japan new drug application-specific bracketing strategies for critical and noncritical aspects of the manufacturing process, regulatory requirements related to stability studies, release specifications and testing methods, standard processes involved in pre and postapproval inspections, management of postapproval changes, and Japan regulatory authority's consultation services available to global pharmaceutical companies.     

对EMA草药质量标准指南（第3修订版草案）的思考

草药及其产品的质量标准具有区别于化学药品或生物制品的特殊性，因此欧洲药品管理局（EMA）于2018年发布了“质量标准指南：草药物质、草药制剂和草药产品或传统草药产品的检验程序和可接受标准（第3修订版草案）”。EMA的草药及其产品的情况与我国中药有相似之处，从起始物料到成品多为活性成分未知的复杂混合物。目前我国尚未制定关于中药或中药材（饮片）质量标准相关指导原则。介绍该指南文件的主要内容，并结合中药质量监管情况进行分析，以期EMA相关质量标准制定的指导思路为制定中药质量标准提供参考。     

Equivalence Tests for Shelf Life and Average Drug Content in Stability Studies

Stability testing is a procedure frequently used in the pharmaceutical industry to estimate the shelf life of a drug. Hereby, a standard problem of interest is whether or not to pool a given number of batches to assign a single shelf life for the combined batches. In this paper, we propose two modified methods for the pooling process. One is based on the relative average drug contents of batches at a target shelf life, which basically involves specification of thresholds in relative terms, and the other is tests for the equivalence of shelf lives (using ratios of shelf lives) at a specified lower acceptance criteria of label claim. For both approaches, marginal and simultaneous confidence intervals are established. The methods will be illustrated using two different stability data. A simulation study is conducted to investigate the coverage probability of the proposed methods.     

抗体偶联药物临床前安全性评价考虑要点

抗体偶联药物（Antibody Drug Conjugate,ADC）,是通过连接子将高细胞毒性化合物连接到靶向肿瘤抗原的抗体上,利用抗体靶向识别将化合物递呈至肿瘤细胞表面,杀死肿瘤细胞。ADC药物同时具有抗体和化学药物属性,是将两者的优势结合,极大地提高了药物安全有效性。ADC药物结构复杂,在抗原识别表位、连接位点、连接子以及小分子药物各组分均存在特异性,所以在开展安全性评价研究时有一定的特殊性。本文将从动物种属选择、一般毒性研究、毒代动力学研究、组织交叉反应、免疫原性检测、安全药理研究、遗传毒性研究等方面,阐述ADC药物临床前安全性评价的考虑要点和研究策略。     

Drug targeting systems for cancer chemotherapy

Tumour specific drug targeting has been a very actively investigated area for over 2 decades. Various approaches have involved the use of drug delivery systems that can localise the anticancer agent at the tumour site without damaging the normal cells. For this purpose, various delivery systems that have been utilised are liposomes, microspheres and recently, nanoparticles. Two liposome formulations containing anticancer drugs for example, adriamycin and daunomycin are already on the market in the USA and Europe. Microspheres are also being investigated for delivering various anticancer drugs and protein/peptides for anticancer treatment, and several formulations are in Phase I/II clinical trials. Antitumour drugs have also been linked to tumour specific monoclonal antibodies via various chemical linkages. Doxorubicin was linked to a chimeric monoclonal antibody that was targeted to the Lewis Y antigen. Though this conjugate initially showed potential, it was recently dropped from Phase II clinical trials. Another approach with monoclonal antibodies has been the use of immunotoxins. Immunotoxins initially showed promise as potential anticancer agents at picomolar concentrations but several clinical and preclinical studies have not shown much promise in this regard. Drug containing liposomes and microspheres have been further linked to tumour specific monoclonal antibodies to enhance their tumour specificity. Most of the studies with immunoliposomes or targeted microspheres have not gone beyond the preclinical studies. New therapeutic approaches are presently emerging based on natural products like cytokines, peptide growth factor antagonists, antisense oligonucleotides and specific genes. These approaches need the help of delivery systems to deliver these complex molecules to tumour cells. One of the current pursued approaches is the use of cationic liposomes. Several clinical studies are undergoing with various cationic liposomes and the next few years will demonstrate the usefulness of this approach. In recent years, the problems in cancer treatment have been complicated with the emergence of resistance strains leading to resistant and cross-resistant tumour cells. Several agents have been used to overcome or reverse drug-resistance in solid tumours and it remains a highly pursued area in cancer treatment.     

Toward Shortened the Time-to-Market for Biopharmaceutical Proteins: Improved Fab Protein Expression Stability Using the Cre/lox System in a Multi-Use Clonal Cell Line

Stable gene integration and rapid selection of high-expressing clones are important when developing biopharmaceutical systems to produce a protein of interest. According to regulatory guidelines, the final production clones should be stable through multiple cell generations. To achieve long-term stable expression of Fab genes via recombinase-mediated cassette exchange (RMCE), we modified mutual configurations of the lox sequences. By inversion of the spacer orientation, we avoided the loss of the integrated gene after several dozen cycles of cell division. This feature also prevents reversible transgene integration. Although the RMCE allows us to generate transgenic lines rapidly relative to current methods, it remains difficult to obtain stable industrial cell lines for long-term culturing and for the initial development stage. In this study, we present an approach to shortening the timeline for therapeutic protein development. Our approach provides easy access to the same clonal cell line in the initial development phase, and also for the production of biopharmaceutical proteins.     

尿激酶中分子组分比2种测定方法的建立和比较研究

目的:建立尿激酶中分子组分比测定的分子排阻色谱法与十二烷基硫酸钠毛细管电泳法,并对2种方法的方法学验证与样品测定结果比较.方法:分子排阻色谱法采用TSKgel G2000SWXL色谱柱(7.8 mm ×300 mm,5 μm ),以0.1 mol· L-1磷酸二氢钠缓冲液(pH 3.0 )为流动相,流速0.5 mL ?...     

Characterization of Ring-Opening Reaction of Succinimide Linkers in ADCs

A new class of highly potent biopharmaceutical drugs, antibody-drug conjugates (ADCs), has been proven to be clinically effective to treat oncologic diseases. ADCs contain 3 major components: the monoclonal antibody, cytotoxic drug, and chemical linker. THIOMAB? drug conjugates and interchain-cysteine ADCs are common ADC platforms that apply thiol-maleimide chemistry via Michael addition to conjugate linker-drugs to cysteine residues. However, the resulting succinimide ring in the linker is susceptible to ring-opening reactions via hydrolysis, especially at high pH and elevated temperatures. Once the succinimide ring is opened, in vivo stability of the ADCs can be changed and the therapeutic activity will be altered. In this study, we investigated the impact of conjugation sites on succinimide ring opening for ADCs. A new methodology based on imaged capillary isoelectric focusing was developed to monitor the formation of succinimide ring-opened products. In addition, a reverse-phase high-performance liquid chromatography method was used to monitor site-specific ring-opening reactions. Our data confirmed that succinimide ring-opening rates in ADCs are conjugation-site dependent. With a good understanding of the conjugation site impact on final product’s stability, it is potentially feasible to modify ring-opening rates in vitro to achieve desirable in vivo stability and biological activity.     

FDA “肽类药物产品临床药理学的考虑的供企业用的指导原则草案” 及其启示

美国食品药品管理局（FDA）于2023年9月发布了“肽类药物产品临床药理学的考虑的供企业用的指导原则草案”。该指导原则描述了FDA对肽类药物产品开发方案的临床药理学的建议,包括肝损害、药物-药物相互作用评估、心电图按心率校正的QT间期（QTc）延长风险评估以及免疫原性风险及其对药动学、安全性和有效性评估的影响。详细介绍FDA该指导原则的主要内容,期望对我国肽类药物产品临床药理学研究和监管有所启示。     

Novel Central Nervous System Drug Delivery Systems

For decades, biomedical and pharmaceutical researchers have worked to devise new and more effective therapeutics to treat diseases affecting the central nervous system. The blood–brain barrier effectively protects the brain, but poses a profound challenge to drug delivery across this barrier. Many traditional drugs cannot cross the blood–brain barrier in appreciable concentrations, with less than 1% of most drugs reaching the central nervous system, leading to a lack of available treatments for many central nervous system diseases, such as stroke, neurodegenerative disorders, and brain tumors. Due to the ineffective nature of most treatments for central nervous system disorders, the development of novel drug delivery systems is an area of great interest and active research. Multiple novel strategies show promise for effective central nervous system drug delivery, giving potential for more effective and safer therapies in the future. This review outlines several novel drug delivery techniques, including intranasal drug delivery, nanoparticles, drug modifications, convection‐enhanced infusion, and ultrasound‐mediated drug delivery. It also assesses possible clinical applications, limitations, and examples of current clinical and preclinical research for each of these drug delivery approaches. Improved central nervous system drug delivery is extremely important and will allow for improved treatment of central nervous system diseases, causing improved therapies for those who are affected by central nervous system diseases.     

Anti-EGFR strategies as an incremental step for the treatment of colorectal cancer patients: moving from scientific evidence to clinical practice

The epidermal growth factor receptor (EGFR) is a 170,000 Da transmembrane glycoprotein involved in signalling pathways affecting cellular growth, differentiation and proliferation. An abnormal overexpression of the EGFR has been described in many human tumours and implicated in the development and prognosis of malignancies, thus representing not only a possible prognostic marker, but primarily a rational molecular target for a new class of anticancer agents. Several clinical trials have been reported with the use of EGFR-targeted monoclonal antibodies and tyrosine kinase inhibitors, mainly in combination with chemotherapy for advanced colorectal cancer patients. Taken together, results available so far suggest that anti-EGFR treatment strategies represent an incremental step for the the treatment of colorectal cencer patients with a manageable and acceptable toxicity profile. Nevertheless, many critical issues are yet unresolved, such as the optimal chemotherapy regimen to combine with anti-EGFR treatment and the most adequate patients setting. Moreover, the biological selection of colorectal tumours most likely to benefit from this treatment approach is still to be defined.     

FDA的《长效局部麻醉药开发供企业用指导原则草案》介绍

美国食品药品监督管理局（FDA）于2023年3月发布了《长效局部麻醉药开发的供企业用的指导原则草案》。该指导原则针对长效局部麻醉药新药申请的不同适应证和说明书的声明,尤其是术后镇痛,提出了对这类药物开发和试验设计的详细而具体的许多建议,包括一般临床药理学、人因工程学评价、试验设计、临床有效性评价、临床安全性评价和说明书的声明等诸方面。而我国目前尚没有类似的指导原则,详细介绍FDA该指导原则的主要内容,期望对我国这类药物的开发研究及其监管有所帮助。     

How Modeling and Simulation Have Enhanced Decision Making in New Drug Development

The idea of model-based drug development championed by Lewis Sheiner, in which pharmacostatistical models of drug efficacy and safety are developed from preclinical and available clinical data, offers a quantitative approach to improving drug development and development decision-making. Examples are presented that support this paradigm. The first example describes a preclinical model of behavioral activity to predict potency and time-course of response in humans and assess the potential for differentiation between compounds. This example illustrates how modeling procedures expounded by Lewis Sheiner provided the means to differentiate potency and the lag time between drug exposure and response and allow for rapid decision making and dose selection. The second example involves planning a Phase 2a dose-ranging and proof of concept trial in Alzheimer’s disease (AD). The issue was how to proceed with the study and what criteria to use for a go/no go decision. The combined knowledge of AD disease progression, and preclinical and clinical information about the drug were used to simulate various clinical trial scenarios to identify an efficient and effective Phase 2 study. A design was selected and carried out resulting in a number of important learning experiences as well as extensive financial savings. The motivation for this case in point was the “Learn-Confirm” paradigm described by Lewis Sheiner. The final example describes the use of Pharmacokinetic and Pharmacodynamic (PK/PD) modeling and simulation to confirm efficacy across doses. In the New Drug Application for gabapentin, data from two adequate and well-controlled clinical trials was submitted to the Food and Drug Administration (FDA) in support of the approval of the indication for the treatment of post-herpetic neuralgia. The clinical trial data was not replicated for each of the sought dose levels in the drug application presenting a regulatory dilemma. Exposure response analysis submitted in the New Drug Application was applied to confirm the evidence of efficacy across these dose levels. Modeling and simulation analyses showed that the two studies corroborate each other with respect to the pain relief profiles. The use of PK/PD information confirmed evidence of efficacy across the three studied doses, eliminating the need for additional clinical trials and thus supporting the approval of the product. It can be speculated that the work by Lewis Sheiner reflected in the FDA document titled “Innovation or Stagnation: Challenge and Opportunity on the Critical Path to New Medical Products” made this scientific approach to the drug approval process possible.