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Biosimilar development has a well-documented foundation of product quality and extensive comparative analytics providing the bulk of the "totality of the evidence" that a proposed product is biosimilar to its reference product. This work provides a retrospective evaluation of a single critical quality attribute-high mannose glycans for monoclonal antibody biosimilars. Given the well-established conclusion that high mannose glycans can impact pharmacokinetic (PK) profile, we performed a retrospective evaluation of 21 monoclonal antibody biosimilar programs (those licensed before April 2022), their levels of glycans, and the methods used to study them. We provide herein a summary of the methods used and their relative performance. We also present a subset analysis for seven biosimilar products with levels of high mannose that differ from the corresponding reference product (and where other differences in quality attributes between the two that may influence PK profile were not observed or considered minor) and compared the PK profiles. Critically, this analysis has demonstrated that the measurement of glycan profiles is highly precise, reproducible within and across programs, and can detect differences in mannose levels, even those that do not impact PK. These results provide support that analytics rather than pharmacokinetic data may be sufficient to predict whether differences within a certain magnitude of this attribute are likely to impact PK. This work enhances the Agency's understanding of this issue allowing for better understanding of challenges faced by the biotechnology industry developing biosimilars.

This workshop report summarizes the presentations, the breakout session outcomes, and the speaker panel discussions from the PDA Biosimilars Workshop held September 27-28, 2018, in Washington, DC. This format was deliberately selected for the workshop with the expectation of delivering a post-workshop paper on current best practices and existing challenges for sponsors. The event, co-chaired by Dr. Stephan Krause (AstraZeneca Biologics) and Dr. Emanuela Lacana (CDER/FDA), was attended by 140 agency and industry representatives. The workshop was separated into three major sessions P1: Regulatory Perspective, P2: Challenges in Biosimilar Development, and P3: Demonstrating Analytical Similarity. Each of the three sessions started with agency and industry presentations. Participants then split into two concurrent roundtable discussion groups to hear the answers to questions that had been provided to all participants one week prior to the event. The sessions were recorded. This paper provides consolidated answers to specific case studies for current challenges to sponsors and agencies. In addition, the panel discussion notes following each breakout roundtable session, as well as brief talk summaries of all speakers, are provided. The first session explored the challenges encountered with submission of biosimilar marketing applications from the perspectives of regulatory agencies. Expectations for a successful submission of the chemistry, manufacturing, and controls (CMC) information were described. The second session addressed high-level technical challenges and how to avoid pitfalls frequently encountered during biosimilar candidate development, including data quality expectations, creation of the final control strategy, and strategic choices necessary for candidate selection and development. Both regulatory perspectives and industry experience were shared. The last session explored the use of statistical tools to provide meaningful contributions to the demonstration of analytical similarity. The presentations highlighted common issues and practical challenges that arise during the application of statistical tools.

Pompe disease is a lysosomal storage disorder caused by deficiency in the enzyme acid α-glucosidase (GAA). Pompe disease is characterized by the accumulation of glycogen, predominantly in muscle tissue, leading to progressive muscle weakness, loss of motor, respiratory, and, in the infantile-onset form, cardiac function. Disease progression is highly variable depending on phenotype, but premature death due to respiratory complications occurs in most patients. Beginning in 2006, approved alglucosidase alfa enzyme replacement therapies [recombinant human (rh) GAA] have been available to treat Pompe patients. Treatment of classic infantile-onset patients, who manifest the severest form of the disease, with alglucosidase alfa (Myozyme®) has led to extended survival and an evolving understanding of the pathophysiology and course of the disease. Moreover, such treatment has brought to light the role of the immune response in abrogating the efficacy of rhGAA in classic infantile-onset patients with severe genetic mutations. Thus, optimization of treatment for such patients includes development and utilization of strategies to prevent or eliminate immune responses, including modulating the immune system (prophylactic and therapeutic immune tolerance induction regimens) and engineering the enzyme to be less immunogenic and more effective. Future research is also critical for evaluating and mitigating novel disease-associated pathologies uncovered by prolonged survival of infantile-onset patients including development of novel therapeutics, and for protein design strategies to increase delivery of enzyme replacement therapy to critical target tissues. Such efforts would be greatly bolstered by further development of predictive animal models and biomarkers to facilitate clinical trials and patient management. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

The October 2015 FDA/PQRI Conference on Advancing Product Quality provided a forum for the exchange of ideas focused on drug product quality between regulatory agencies, the pharmaceutical industry, and academia. Key topics of the 2015 conference were (i) emerging regulatory initiatives; (ii) regulatory submission, assessment, and inspection; (iii) product and process development; and (iv) manufacturing, risk management, and quality assurance. Key discussion points and recommendations for each track and session have been captured. With powerful advancements in product quality encompassing regulatory, industrial, and technological elements, an era of rapidly improving pharmaceutical quality is underway. At the conference, one theme prevailed through all sessions: regulators, industry, and academia are aligned in their desire for drug product quality on behalf of the ultimate stakeholder–the patient. 3D three dimensional, ANDA abbreviated new drug application, API active pharmaceutical ingredient, ASTM American society for testing and materials, BCS biopharmaceutics classification system, BLA biological license application, CGMP current good manufacturing practice, CMA critical material attribute, CMC chemistry manufacturing and controls, CPP critical process parameters, CQA critical quality attribute, CU content uniformity, DLS dynamic light scattering, DOE design of experiment, EMA European Medicines Agency, EWG Expert Working Group, FDA Food and Drug Administration, GDUFA generic drug user fee amendments, HCl Hydrogen Chloride, ICH International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use, IND investigational new drug, IQA integrated quality assessment, IR immediate release, IR information request, ISPE International Society for Pharmaceutical Engineering, MIT Massachusetts Institute of Technology, NDA new drug application, NIPP new inspection protocols project, NIR near-infrared spectroscopy, OPQ office of pharmaceutical quality, PAI pre-approval inspection, PAT process analytical technology, PDUFA prescription drug user fee act, PHS public health service, PQRI Product Quality Research Institute, PQS pharmaceutical quality system, QbD quality by design, QMS quality management system, QRM quality risk management, QTPP quality target product profile, RPM revolutions per minute, RTRT real time release testing, SUPAC scale-up and post-approval changes, UDU uniformity of dosage units, USP U.S. Pharmacopeial Convention.

On September 16 and 17, 2014, the Food and Drug Administration (FDA) and Product Quality Research Institute (PQRI) inaugurated their Conference on Evolving Product Quality. The Conference is conceived as an annual forum in which scientists from regulatory agencies, industry, and academia may exchange viewpoints and work together to advance pharmaceutical quality. This Conference Summary Report highlights key topics of this conference, including (1) risk-based approaches to pharmaceutical development, manufacturing, regulatory assessment, and post-approval changes; (2) FDA-proposed quality metrics for products, facilities, and quality management systems; (3) performance-based quality assessment and clinically relevant specifications; (4) recent developments and implementation of continuous manufacturing processes, question-based review, and European Medicines Agency (EMA)-FDA pilot for Quality-by-Design (QbD) applications; and (5) breakthrough therapies, biosimilars, and international harmonization, focusing on ICH M7 and Q3D guidelines. The second FDA/PQRI conference on advancing product quality is planned for October 5–7, 2015.

Whether new versions of currently marketed, or de novo biological drugs, biobetters are products specifically designed to maximize clinical performance. Performance optimization may include, among other improvements, enhanced targeting and delivery, increased activity and half-life, and reduced immunogenicity. Thus, it is critical that such products are developed efficiently and quickly, to allow patients access to drugs that provide maximum clinical benefits.

The apoptosis-linked gene product, ALG-2, is a member of the family of intracellular Ca(2+)-binding proteins and a part of the apoptotic machinery controlled by T-cell receptor (TCR), Fas, and glucocorticoid signals. To explore the physiologic function of ALG-2 in T-cell development and function, we generated mice harboring a null mutation in the alg-2 gene. The alg-2 null mutant mice were viable and fertile and showed neither gross developmental abnormality nor immune dysfunction. Analyses of apoptotic responses of ALG-2-deficient T cells demonstrated that ALG-2 deficiency failed to block apoptosis induced by TCR, Fas, or dexamethasone signals. These findings indicate that ALG-2 is physiologically dispensable for apoptotic responses induced by the above signaling pathways and suggest that other functionally redundant proteins might exist in mammalian cells.

A series of evidences suggests that enhanced susceptibility to programmed cell death (PCD) is a major pathogenetic factor in Alzheimer's disease (AD). We investigated this issue, analyzing amyloid beta-protein (A beta) production in a model of neuronal PCD, induced by staurosporine in a murine neuroblastoma cell line. When PCD was induced, a 280-290% secreted A beta occurred, in spite of a 20% metabolism and an unchanged A betaPP expression. The increased intracellular A beta reactivity largely colocalized with a marker of ER. Inhibition of caspases blocked the cleavage at the C-terminus of beta PP, but only partially rescued A beta overproduction caused by staurosporine treatment. Our findings suggest that PCD fosters the physiological pathways of A beta production characteristic of neuronal cells, and they confirm the theory that unbalance of PCD is a central event in AD pathogenesis. Moreover, our data indicate that still unidentified cellular mechanisms, other than caspases activation, are responsible of the specific alteration of A betaPP processing during PCD.

Sphingosine kinase catalyzes the phosphorylation of sphingosine to form sphingosine 1-phosphate (SPP), a novel lipid mediator with both intra- and extracellular functions. Based on sequence identity to murine sphingosine kinase (mSPHK1a), we cloned and characterized the first human sphingosine kinase (hSPHK1). The open reading frame of hSPHK1 encodes a 384 amino acid protein with 85% identity and 92% similarity to mSPHK1a at the amino acid level. Similar to mSPHK1a, when HEK293 cells were transfected with hSPHK1, there were marked increases in sphingosine kinase activity resulting in elevated SPP levels. hSPHK1 also specifically phosphorylated D-erythro-sphingosine and to a lesser extent sphinganine, but not other lipids, such as D,L-threo-dihydrosphingosine, N,N-dimethylsphingosine, diacylglycerol, ceramide, or phosphatidylinositol. Northern analysis revealed that hSPHK1 was widely expressed with highest levels in adult liver, kidney, heart and skeletal muscle. Thus, hSPHK1 belongs to a highly conserved unique lipid kinase family that regulates diverse biological functions.

Programmed cell death is a process required for the normal development of an organism. One of the best understood apoptotic pathways occurs in T lymphocytes and is mediated by Fas/Fas ligand (FasL) interaction. During studies of apoptosis induced by T cell-receptor engagement, we identified ALG-4F , a truncated transcript that prevents T cell-receptor-induced FasL upregulation and cell death. Overexpression of full-length ALG-4 induced transcription of FasL and, consequently, apoptosis. These results indicate that ALG-4 is necessary and sufficient for FasL expression. Fas/FasL interaction initiates cell death in many other systems, and its dysregulation is a mechanism by which several pathologic conditions arise. Understanding the molecular mechanisms of FasL regulation could be very useful in elucidating how these diseases develop and in identifying potential therapeutic targets.

ALG-3, a truncated mouse homologue of the chromosome 1 familial Alzheimer's disease gene PS2, rescues T hybridoma 3DO cells from T-cell receptor-induced apoptosis by inhibiting Fas ligand induction and Fas signaling. Here we show that ALG-3 transfected 3DO cells express a COOH-terminal PS2 polypeptide. Overexpression of PS2 in ALG-3 transfected 3DO cells reconstitutes sensitivity to receptor-induced cell death, suggesting that the artificial PS2 polypeptide functions as a dominant negative mutant of PS2. ALG-3 and antisense PS2 protect PC12 cells from glutamate-induced apoptosis but not from death induced by hydrogen peroxide or the free radical MPP+. Thus, the PS2 gene is required for some forms of cell death in diverse cell types, and its function is opposed by ALG-3.

The lysophospholipids, lysophosphatidic acid, sphingosine-1-phosphate, and sphingosylphosphorylcholine (SPC), are bioactive lipid molecules that regulate diverse biological processes. Although the specific G protein-coupled receptors for lysophosphatidic acid and sphingosine-1-phosphate have been well-characterized, much less is known of the SPC receptors. It has been reported that ovarian cancer G protein-coupled receptor 1 (OGR1) is a high affinity receptor for SPC, and its closely related homologue GPR4 is a high affinity receptor for SPC with low affinity for lysophosphatidylcholine (LPC). However, in a functional assay to examine the specificity of ligand binding, we found that neither SPC nor LPC, or other related lysophospholipids, induced internalization of GPR4 from the plasma membrane. In agreement, these lysolipids also did not induce translocation of beta-arrestin2-GFP from the cytosol to the plasma membrane in GPR4 expressing cells. However, when these cells were cotransfected with G protein-coupled receptor kinase 2, in the absence of added ligands, beta-arrestin2-GFP accumulated in cytoplasmic vesicles, reminiscent of vesicular labeling usually observed after agonist stimulation of GPCRs. In addition, neither SPC nor LPC stimulated the binding of GTPgammaS to membranes prepared from GPR4 expressing cells and did not activate ERK1/2. Surprisingly, enforced expression of GPR4 inhibited activation of ERK1/2 induced by several stimuli, including SPC, sphingosine-1-phosphate, and even EGF. Collectively, our results suggest that SPC and LPC are not the ligands for GPR4 and that this receptor may constitutively inhibit ERK1/2 activation.

Programmed cell death (PCD) is a normal event under genetic control that regulates the life span of different cell types in multicellular organisms. Among other physiological processes, PCD plays a pivotal role in the regulation of the immune system. Using a functional selection strategy we have isolated and characterized genes involved in T-cell receptor-induced apoptosis. One, ALG-2 , is a Ca 2+ -binding protein that participates in regulatory events that occur late in the apoptotic program, where several death signals converge. Another, ALG-3 , is a mouse homologue of the chromosome 1 familial Alzheimer's disease gene PS2 . ALG-3 codes for a truncated PS2 polypeptide that antagonizes the apoptotic role of PS2. A PS2 mutation associated with Alzheimer's disease generates a molecule with enhanced apoptotic activity indicating that it might accelerate the process of neurodegeneration that occurs in this disease.

Two apoptosis-linked genes, named ALG-2 and ALG-3, were identified by means of a functional selection strategy. ALG-2 codes for a Ca(2+)-binding protein required for T cell receptor-, Fas-, and glucocorticoid-induced cell death. ALG-3, a partial complementary DNA that is homologous to the familial Alzheimer's disease gene STM2, rescues a T cell hybridoma from T cell receptor- and Fas-induced apoptosis. These findings suggest that ALG-2 may mediate Ca(2+)-regulated signals along the death pathway and that cell death may play a role in Alzheimer's disease.

Overexpression of the familial Alzheimer's disease gene Presenilin 2 (PS2) in nerve growth factor-differentiated PC12 cells increased apoptosis induced by trophic factor withdrawal or beta-amyloid. Transfection of antisense PS2 conferred protection against apoptosis induced by trophic withdrawal in nerve growth factor-differentiated or amyloid precursor protein-expressing PC12 cells. The apoptotic cell death induced by PS2 protein was sensitive to pertussis toxin, suggesting that heterotrimeric GTP-binding proteins are involved. A PS2 mutation associated with familial Alzheimer's disease was found to generate a molecule with enhanced basal apoptotic activity. This gain of function might accelerate the process of neurodegeneration that occurs in Alzheimer's disease, leading to the earlier age of onset characteristic of familial Alzheimer's disease.