Nonclinical Development of Novel Biologics, Biosimilars, Vaccines and Specialty Biologics

Lisa M. Plitnick, Danuta Herzyk, Lisa Plitnick, Danuta Herzyk, Lisa M. Plitnick

• Publisher: Academic Press
• Year: 2013
• ISBN:
  9780123948236
• Topic: Medicine
• Subtopic: Toxicology

Nonclinical Development of Novel Biologics, Biosimilars, Vaccines and Specialty Biologics is a complete reference devoted to the nonclinical safety assessment of novel biopharmaceuticals, biosimilars, vaccines, cell and gene therapies and blood products. This book compares and contrasts these types of biologics with one another and with small molecule drugs, while incorporating the most current and essential international regulatory documents. Each section discusses a different type of biologic, as well as early characterization strategies, principles of study design, preclinical pharmacokinetics and pharmacodynamics and preclinical assays. An edited book that is authored by leading experts in the field, this comprehensive reference provides critical insights to all researchers involved in early through late stage biologics.

• Provides in-depth coverage of the process of nonclinical safety assessment and comprehensive reviews of each type of biopharmaceutical
• Contains the most pertinent international regulatory guidance documents for nonclinical evaluation
• Covers early de-risking strategies and designs of safety assessment programs for novel biopharmaceuticals and vaccines, as well as follow-on biologics or "biosimilars"
• A multi-authored book with chapters written by qualified experts in their respective fields

Section I

Development of Biopharmaceuticals Defined as Novel Biologics

Chapter 1 Overview of Biopharmaceuticals and Comparison with Small-molecule Drug Development

Chapter 2 Regulatory Guidelines and their Application in the Nonclinical Evaluation of Biological Medicines

Chapter 3 Early De-risking Strategy for Novel Biotherapeutics

Chapter 4 Novel Biopharmaceuticals

Chapter 1

Overview of Biopharmaceuticals and Comparison with Small-molecule Drug Development

Theresa Reynolds, Christina de Zafra, Amy Kim and Thomas R. Gelzleichter, Department of Safety Assessment, Genentech, Inc., South San Francisco, CA, USA

Introduction

Therapeutic proteins have been an important component of medical practice since the late nineteenth century, when the protective properties of passive immunization were discovered in blood transferred from pathogen-infected animals [1,2]. This important discovery was quickly followed by early twentieth century success with pancreatic extracts in the treatment of diabetes mellitus [3]. Recombinant DNA technology enabled the mass production of proteins and antibodies using living cells (bacterial, yeast, plant, insect, or mammalian) using well-defined bioprocess methods. The resulting products have a defined specificity and uniformity, which is a vast improvement over previous methods of extraction and purification of proteins from human or animal blood and tissues. Recombinant DNA-derived medicinal products are often interchangeably referred to as “biopharmaceuticals,” “biotherapeutics,” “biologicals,” or “biologics.”

This chapter introduces the various classes of therapeutics that are produced using recombinant DNA technology, and provides background on the history and evolution of therapeutic hormones, enzymes, cytokines, and monoclonal antibodies from an early understanding of their value in the treatment of disease to present day production of genetically engineered human proteins and novel constructs designed to improve uniformity, safety, efficacy, or duration of effect. The introduction of these products to the medical armamentarium heralded the beginning of the biotechnology industry and revolutionized medicine.

In order to bring these new medicines to patients, some specific considerations and different approaches compared to those previously established for small-molecule drugs were needed to characterize the safety profile of biopharmaceuticals. A comparative review highlighting similarities and differences in the development of biopharmaceuticals and small-molecule drugs is included in this chapter.

History and Evolution of Biopharmaceuticals

The First Protein Therapeutics

In the 1920s and 1930s, prior to the advent of prophylactic vaccines, “serum therapy,” derived from pathogen-infected animals, was employed to treat a variety of infectious diseases including diphtheria, scarlet fever, pneumococcal pneumonia, and meningococcal meningitis [4,5]. Despite relative success in the management of bacterial infections, systemic administration of a heterologous (non-human), mixture of immunoglobulins (Igs) resulted in high risk to patients for immunological toxicities such as allergic or anaphylactoid reactions. Improvements in sanitation and hygiene had a positive impact on both primary infection and contagion, and the discovery and development of antibiotics in the 1930s and 1940s provided a highly effective treatment alternative, which quickly became the standard of care for bacterial infections. As a consequence, the use of animal sera for passive immunization was reserved for toxin-mediated afflictions due to diphtheria, tetanus, botulism, and venomous bites [4–6].

Immunoglobulin preparations derived from human placenta and plasma have been in clinical use since the early to mid-1940s when gamma globulin injections were used for prevention or treatment of viral diseases. Intravenous immunoglobulin (IVIG) infusion continues to be a mainstay of treatment for antibody deficiency disorders and autoimmune and inflammatory conditions such as idiopathic thrombocytopenic purpura and Kawasaki syndrome [7]. In addition, hyperimmune IgG preparations (HIG) purified from the plasma of human donors that have been exposed to viruses such as respiratory syncytial virus (RSV), cytomegalovirus (CMV), or human immunodeficiency virus (HIV) continue to provide therapeutic or prophylactic benefit to vulnerable populations [8–11].

Early therapeutic proteins in clinical use were likewise derived initially from animal, and subsequently from human sources. The identification and purification of insulin from bovine pancreas in 1922 provided glucose control for diabetes patients who had no real treatment options [3]. Clotting factor VIII for hemophilia was initially derived from human plasma, β-glucocerebrosidase for Gaucher’s disease was initially purified from human placenta [12], and human growth hormone was derived from the pituitary of human cadavers [13]. Each of these products would later be replaced by homogeneous and well-characterized protein therapeutics produced through recombinant DNA technology.

Biopharmaceuticals Produced by Recombinant DNA Technology

In 1978, human insulin was produced through genetic engineering [14,15], and in 1982 it became the first biotechnology product to receive US Food and Drug Administration (FDA) approval [16]. The cloning and expression of human insulin ushered in the age of biotechnology and this achievement was rapidly followed by the cloning and expression of human growth hormone [17], leading to US FDA approval in 1985, followed by approval of interferon alphas 2a and 2b in 1986 [16]. The production of large quantities of a single human protein improved patient access to life-saving treatment and reduced the risk of pathogen transmission, or an immune reaction to other animal or human proteins that were present in the product. The tragic consequences of unwitting hepatitis C and HIV transmission to hemophiliacs treated with plasma-derived clotting products in the 1980s lent urgency to the development of a recombinant factor VIII [18,19], as well as the development of screening tools for the blood supply [20].

Alongside gene identification, cloning, and protein expression, Köhler and Milstein’s [21] development of the technology to produce antibodies against a defined target stands as a watershed moment in biotechnology. The fusion of long-lived murine myeloma cells to murine spleen cells from an immunized donor to form a hybridoma capable of secreting antigen-specific antibodies enabled production of monoclonal antibodies as targeted therapeutics for a wide variety of diseases.

Technical developments in the production of antibody therapeutics are reflected in the chronology of marketing approvals. In 1986, muromonab-CD3 (OKT3^®) was approved for use in acute transplant rejection. OKT3^® is a wholly murine monoclonal antibody that was purified from a hybridoma generated via the fusion of a murine myeloma cell and a B cell from mice immunized with human CD3 [22,23]. To create the next generation of monoclonal antibodies, genes encoding the variable region of antibodies produced by murine hybridoma cell lines were ligated to the genes encoding the constant region of human IgG and transfected into murine myeloma [24,25], and later into immortalized mammalian cells [26–28] to produce chimeric antibodies with a defined specificity. Abciximab (Reopro^®) is an antibody fragment (Fab) composed of the binding region only, eliminating the Fc portion, and was the first chimeric biotherapeutic to be approved for human use (1994), followed by the chimeric anti-CD20 antibody rituximab (Rituxan^®) in 1997 [16].

Humanized monoclonal antibodies (mAbs) are produced by transplanting only the rodent residues required for antigen binding onto a human IgG framework. Daclilzumab (Zenapax^®) was the first humanized mAb to be approved for human use in 1997, followed by palivizumab (Synagis^®) and trastuzumab (Herceptin^®) in 1998 [16]. Fully human antibodies can be produced by phage display, where an antigen of interest is screened against a library of diverse human immunoglobulin variable region segments [29,30]. This technology was used to produce adalimumab (Humira^®), the first fully human mAb granted marketing approval by the US FDA [31].

Following on the success of recombinant protein replacement therapies, recombinant proteins expanded into cancer with the 1986 marketing approval of recombinant interferon alphas 2a and 2b (Roferon A^®, Intron A^®, respectively), for the treatment of hairy cell leukemia, a subtype of chronic lymphoid leukemia that affected just 2% of all US leukemia patients at that time [32]. Because of the higher costs of producing biopharmaceutical products relative to small-molecule pharmaceuticals and because proteins require parenteral administration, biopharmaceuticals were niche products in the early years, indicated as replacement therapy, acute treatment for life-threatening indications, or for difficult-to-treat disease areas refractory to the standard of care such as cancer [16,30]. As the underlying mechanisms of disease were elucidated and positive patient outcomes with acceptable benefit/risk profiles emerged with biopharmaceuticals, their use was expanded into chronic diseases, including autoimmune disorders such as asthma, multiple sclerosis, and rheumatoid arthritis [16,31,33].

Recombinant DNA technology made it possible to produce therapeutic human proteins at a large scale with greater purity, homogeneity, stability, and predictable potency than had been available from protein products extracted from animal and human blood and tissues. The state of the art has evolved from one of reduction—purifying a single protein from large quantities of complex, heterogeneous human or animal protein mixture—to a model of controlled expansion: cloning a gene encoding a protein of interest into a prokaryotic or eukaryotic cell and selectively expressing large quantities of a single human protein. This has the advantage of eliminating the need for sources of human plasma (with attendant concerns over pathogenic agents), while improving protein yields and product uniformity.

The Emergence of Novel Constructs

Technological advances in protein and antibody engineering have provided the tools to design biopharmaceuticals with attributes to improve systemic exposure, efficacy, product stability, and safety. For example, site-directed mutagenesis was used to engineer recombinant hemoglobin with the oxygen affinity and stable tetrameric structure necessary for efficient oxygen dissociation to tissues without the renal damage caused by smaller constructs [34,35]. Human insulin has been similarly engineered to improve half-life [36,37] and to reduce aggregation for improved onset of activity [38]. Conjugation of therapeutic proteins to inert polymers such as polyethylene glycol (PEG) to prolong plasma half-life, reduce frequency of administration, and enhance efficacy has provided PEGylated treatment options such as interferon alpha-2a (Pegasys^®), interferon alpha-2b (PegIntron A^®, ViraferonPeg^®), and GM-CSF (Neulasta^®). More recent forms of protein engineering include the creation of fusion proteins such as Ontak^® (denileukin diftitox; recombinant IL-2 + diphtheria toxin), Enbrel^® (etanercept; recombinant TNF receptor + IgG Fc), and Amevive^® (alefacept; LFA-3 + IgG Fc) [31].

Modification of the glycosylation sites of proteins produced in mammalian cells can confer distinct properties. Hyperglycosylation of erythropoietin to produce Aranesp^® (darbepoetin alfa) improved pharmacokinetic properties [39], while afucosylation of mAbs has been shown to enhance binding to FcγRIII and improve effector functions such as antibody-dependent cellular cytotoxicity (ADCC) [40,41]. Other structural alterations to IgGs include amino acid substitutions to the complement component C1q-binding sites to increase complement-dependent cytotoxicity (CDC) activity [42], FcRn mutations to improve plasma half-life through antibody recycling and prevention of lysosomal degradation [43], and modification of hinge regions to positively or negatively modulate both ADCC and CDC effector functions [44].

As of 2010, over 200 biopharmaceuticals have been approved for human use, with clinical indications spanning cancer, autoimmune disorders, metabolic imbalances, and infectious disease [31,45,46]. In the 30 years since recombinant human insulin was first expressed in the laboratory, recombinant D...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Dedication
• Preface
• Contributors
• Acknowledgments
• Section I: Development of Biopharmaceuticals Defined as Novel Biologics
• Section II: Development of Biosimilars
• Section III: Vaccines
• Section IV: Specialty Biologics and Indications
• Color Plates
• Index