mAb Discovery Research Articles

BioNTech to Acquire MAB Discovery's Antibody Generation Unit, Building on Six-Year Collaboration

BioNTech to Acquire MAB Discovery's Antibody Generation Unit, Building on Six-Year Collaboration

A Sortase A Programmable Phage Display Format for Improved Panning of Fab Antibody Libraries

Phage display of combinatorial antibody libraries is a versatile tool in the field of antibody engineering, with diverse applications including monoclonal antibody (mAb) discovery, affinity maturation, and humanization. To improve the selection efficiency of antibody libraries, we developed a new phagemid display system that addresses the complication of bald phage propagation. The phagemid facilitates the biotinylation of fragment of antigen binding (Fab) antibody fragments displayed on phage via Sortase A catalysis and the subsequent enrichment of Fab-displaying phage during selections. In multiple contexts, this selection approach improved the enrichment of target-reactive mAbs by depleting background phage. Panels of cancer cell line-reactive mAbs with high diversity and specificity were isolated from a naïve chimeric rabbit/human Fab library using this approach, highlighting its potential to accelerate antibody engineering efforts and to empower concerted antibody drug and target discovery.

Abstract 5764: Discovery of therapeutic human monoclonal antibody combinations using microfluidics and molecular genomics

Abstract Monoclonal antibodies (mAbs) have proven to be extremely effective immuno-oncology therapeutics that lead to previously unseen durable responses in melanoma, bladder cancer, RCC, lung cancer, and other malignancies. Most mAb therapeutics, including current anti-PD-1 drugs, were discovered by mouse immunization followed by hybridoma isolation. Unfortunately, mouse hybridomas are highly inefficient, capturing only about 0.1% of the total B-cell diversity in immunized mice. As a result, discovery programs that use mouse hybridomas often struggle to find high-affinity, developable antibodies against certain challenging targets, even when using humanized mice. We have developed a novel method for mouse mAb discovery that leverages microfluidics, multiplex PCR, yeast single chain variable fragment (scFv) display, and fluorescence-activated cell sorting (FACS). Our technology is significantly faster and more comprehensive than conventional hybridoma screening. We recently embarked on a discovery campaign for 17 immuno-oncology targets, including PD-1, CTLA-4, GITR, and OX40. We injected chimeric humanized mice (Trianni) with antigen twice weekly for three weeks. Lymph nodes, splenocytes, and bone marrow were removed from the mice and made into single-cell suspensions. We then isolated B cells using negative selection magnetic beads, and used microfluidics to process >4 million cells per mouse, generating DNA libraries that keep single cell heavy and light chain immunoglobulin (Ig) pairing intact. We built yeast scFv libraries for each of the 17 antigen-specific B cell repertoires with a C-terminal c-myc tag. To select scFv-expressing cells that bind to antigen, biotinylated antigen was added to the yeast cells at 7-250nM and then stained with fluorescent streptavidin. We then flow sorted for the top double-positive cells (c-myc+/antigen+). Finally, we deep sequenced the libraries of enriched high-affinity scFvs, which yielded the sequences for >2,000 candidate scFv binders. Hundreds of these candidate scFvs were engineered into full-length mAb constructs and expressed transiently in Chinese hamster ovary (CHO) cells. To develop candidates for clinical use, we performed assays for binding kinetics, cell surface antigen binding, in vitro T-cell activation, and epitope binning. Candidates that are high affinity, bind cell surface antigen, and induce immune cell activation are now being tested in combinations for in vitro and in vivo efficacy. Combinations that have significantly better in vitro and in vivo efficacy than benchmark checkpoint inhibitors currently on the market will be moved forward into clinical studies. Citation Format: David S. Johnson, Adam S. Adler, Rena Mizrahi, Carter Keller. Discovery of therapeutic human monoclonal antibody combinations using microfluidics and molecular genomics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5764.

Analysis of the effect of promoter type and skin pretreatment on antigen expression and antibody response after gene gun-based immunization.

Monoclonal antibodies (mAbs) have enabled numerous basic research discoveries and therapeutic approaches for many protein classes. However, there still exist a number of target classes, such as multi-pass membrane proteins, for which antibody discovery is difficult, due in part to lack of high quality, recombinant protein. Here we describe the impact of several parameters on antigen expression and the development of mAbs against human claudin 4 (CLDN4), a potential multi-indication cancer target. Using gene gun-based DNA delivery and bioluminescence imaging, we optimize promoter type by comparing expression profiles of four robust in vivo promoters. In addition, we observe that most vectors rapidly lose expression, ultimately reaching almost background levels by three days post-delivery. Recognizing this limitation, we next explored skin pretreatment strategies as an orthogonal method to further boost the efficiency of mAb generation. We show that SDS pretreatment can boost antigen expression, but fails to significantly increase mAb discovery efficiency. In contrast, we find that sandpaper pretreatment yields 5-fold more FACS+ anti-CLDN4 hybridomas, without impacting antigen expression. Our findings coupled with other strategies to improve DNA immunizations should improve the success of mAb discovery against other challenging targets and enable the generation of critical research tools and therapeutic candidates.

Human monoclonal antibodies as candidate therapeutics against emerging viruses.

The emergence of new pathogens, such as severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV), and Ebola virus, poses serious challenges to global public health and highlights the urgent need for novel antiviral approaches. Monoclonal antibodies (mAbs) have been successfully used to treat various diseases, particularly cancer and immunological disorders. Antigen-specific mAbs have been isolated using several different approaches, including hybridoma, transgenic mice, phage display, yeast display, and single B-cell isolation. Consequently, an increasing number of mAbs, which exhibit high potency against emerging viruses in vitro and in animal models of infection, have been developed. In this paper, we summarize historical trends and recent developments in mAb discovery, compare the advantages and disadvantages of various approaches to mAb production, and discuss the potential use of such strategies for the development of antivirals against emerging diseases. We also review the application of recently developed human mAbs against SARS-CoV, MERS-CoV, and Ebola virus and discuss prospects for the development of mAbs as therapeutic agents against emerging viral diseases.

High-throughput screening of hybridoma supernatants using multiplexed fluorescent cell barcoding on live cells

With current available assay formats using either immobilized protein (ELISA, enzyme-linked immunosorbent assay) or immunostaining of fixed cells for primary monoclonal antibody (mAb) screening, researchers often fail to identify and characterize antibodies that recognize the native conformation of cell-surface antigens. Therefore, screening using live cells has become an integral and important step contributing to the successful identification of therapeutic antibody candidates. Thus the need for developing high-throughput screening (HTS) technologies using live cells has become a major priority for therapeutic mAb discovery and development.We have developed a novel technique called Multiplexed Fluorescent Cell Barcoding (MFCB), a flow cytometry-based method based upon the Fluorescent Cell Barcoding (FCB) technique and the Luminex fluorescent bead array system, but is applicable to high-through mAb screens on live cells. Using this technique in our system, we can simultaneously identify or characterize the antibody-antigen binding of up to nine unique fluorescent labeled cell populations in the time that it would normally take to process a single population. This has significantly reduced the amount of time needed for the identification of potential lead candidates.This new technology enables investigators to conduct large-scale primary hybridoma screens using flow cytometry. This in turn has allowed us to screen antibodies more efficiently than before and streamline identification and characterization of lead molecules.

Strategies for Selecting Membrane Protein-Specific Antibodies using Phage Display with Cell-Based Panning.

Membrane proteins are attractive targets for monoclonal antibody (mAb) discovery and development. Although several approved mAbs against membrane proteins have been isolated from phage antibody libraries, the process is challenging, as it requires the presentation of a correctly folded protein to screen the antibody library. Cell-based panning could represent the optimal method for antibody discovery against membrane proteins, since it allows for presentation in their natural conformation along with the appropriate post-translational modifications. Nevertheless, screening antibodies against a desired antigen, within a selected cell line, may be difficult due to the abundance of irrelevant organic molecules, which can potentially obscure the antigen of interest. This review will provide a comprehensive overview of the different cell-based phage panning strategies, with an emphasis placed on the optimisation of four critical panning conditions: cell surface antigen presentation, non-specific binding events, incubation time, and temperature and recovery of phage binders.

A method for the isolation and characterization of functional murine monoclonal antibodies by single B cell cloning

Monoclonal antibody technologies have enabled dramatic advances in immunology, the study of infectious disease, and modern medicine over the past 40years. However, many monoclonal antibody discovery procedures are labor- and time-intensive, low efficiency, and expensive. Here we describe an optimized mAb discovery platform for the rapid and efficient isolation, cloning and characterization of monoclonal antibodies in murine systems. In this platform, antigen-binding splenic B cells from immunized mice are isolated by FACS and cocultured with CD40L positive cells to induce proliferation and mAb production. After 12days of coculture, cell culture supernatants are screened for antigen, and IgG positivity and RNA is isolated for reverse-transcription. Positive-well cDNA is then amplified by PCR and the resulting amplicons can be cloned into ligation-independent expression vectors, which are then used directly to transfect HEK293 cells for recombinant antibody production. After 4days of growth, conditioned medium can be screened using biolayer interferometry for antigen binding and affinity measurements. Using this method, we were able to isolate six unique, functional monoclonal antibodies against an antigen of the human malaria parasite Plasmodium falciparum. Importantly, this method incorporates several important advances that circumvent the need for single-cell PCR, restriction cloning, and large scale protein production, and can be applied to a wide array of protein antigens.

Development of Anti-IL-1R3 Monoclonal Antibodies for Treating Cancer and IL-1 Family-Mediated Inflammation

IL-1R3 is the co-receptor required for signaling of IL-1β, IL-1α, IL-33 and IL-36α, β and γ. The naturally occurring IL-1 receptor antagonist (anakinra), is used to block IL-1β, and IL-1α and clinical trials have demonstrated a reduction in progression to multiple myeloma as well as increased overall survival in stage IV pancreatic cancer using anakinra. In addition, a monoclonal antibody that targets IL-1α increases overall survival in metastatic colorectal cancer. However, blocking IL-1R3 would reduce not only IL-1β and IL-1α but also IL-33 as well as IL-36α, β and γ. The data described below reveal the broad efficacy of anti-IL-1R3.In the present studies, monoclonal humanized anti-IL-1R3 antibodies were studied in the mixed leukocyte reaction (MLR), in peripheral mononuclear cells (PBMC) stimulated with LPS, heat-killed Candida albicans or anti-CD3/antiCD28 as well as in THP-1 cells, a cell line derived from a patient with acute myeloid leukemia (AML). In the MLR, anti-IL-1R3 at 5 µg/mL reduced IFNγ by 81% and IL-6 by 48% compared to 36% by anakinra. In LPS-stimulated PBMCs, IL-6 was reduced by 40% and 58% with anakinra and anti-IL-1R3 respectively. Using heat-killed Candida, the suppression of IL-6 production by anti-IL-1R3 was up to 70%, comparable to anakinra. Immuno-stimulation using anti-CD3/CD28 resulted in a similar inhibition capacity for anakinra (42%) and anti-IL-1R3 (45%) on IL-6 production also. Since neutralizing anti-IL-1α antibodies have increased overall survival in metastatic colorectal cancer, we also measured the effect of anti-IL-1R3 on intracellular levels of IL-1α. In PBMCs stimulated with LPS, the levels of IL-1α were reduced by 35% in cells cultured with anakinra at 10 µg/mL and by 66% in cells exposed to anti-IL-1R3 at same concentration. Activating PBMCs with anti-CD3/anti-CD28 led to a reduction in IL-1α by anakinra of 17%, whereas anti-IL-1R3 suppressed by 29%. We next examined the effect on THP-1 cells as a model for blocking IL-1 family members in AML. THP-1 were differentiated with phorbol myristate acetate (PMA) for 3 hours, washed and subsequently rested for 3 days. The cells were then stimulated with LPS for 3 hours and anti-IL-1R3 was added for 1 hour followed by inflammasome activation with ATP. The reduction in secretion of IL-1β was here 30% at 5 µg/mL of anti-IL-1R3.Collectively, these studies indicate that antibody blockade of IL-1R3 is effective in reducing cytokines from primary cells using in-vitro models of organ rejection, infection and immunostimulation. In THP-1 cells, the reduction in inflammasome-dependent IL-1β suggests that anti-IL-1R3 can be used to treat acute myeloid leukemia, or progression to multiple myeloma. Since anti-IL-1R3 inhibits the signaling through IL-1R1, both IL-1α and IL-1β are targeted by this antibody. Suggesting a future role for this antibody in not only AML, but also other cancer types dominated by IL-1 mediated inflammation, such as metastatic colorectal and pancreatic cancer. DisclosuresFischer:MAB Discovery GmbH: Employment. Pollyea:Ariad: Other: advisory board; Pfizer: Other: advisory board, Research Funding; Glycomimetics: Other: DSMB member; Alexion: Other: advisory board; Celgene: Other: advisory board, Research Funding.

Coupling enrichment methods with proteomics for understanding and treating disease.

Owing to recent advances in proteomics analytical methods and bioinformatics capabilities there is a growing trend toward using these capabilities for the development of drugs to treat human disease, including target and drug evaluation, understanding mechanisms of drug action, and biomarker discovery. Currently, the genetic sequences of many major organisms are available, which have helped greatly in characterizing proteomes in model animal systems and humans. Through proteomics, global profiles of different disease states can be characterized (e.g. changes in types and relative levels as well as changes in PTMs such as glycosylation or phosphorylation). Although intracellular proteomics can provide a broad overview of physiology of cells and tissues, it has been difficult to quantify the low abundance proteins which can be important for understanding the diseased states and treatment progression. For this reason, there is increasing interest in coupling comparative proteomics methods with subcellular fractionation and enrichment techniques for membranes, nucleus, phosphoproteome, glycoproteome as well as low abundance serum proteins. In this review, we will provide examples of where the utilization of different proteomics-coupled enrichment techniques has aided target and biomarker discovery, understanding the drug targeting mechanism, and mAb discovery. Taken together, these improvements will help to provide a better understanding of the pathophysiology of various diseases including cancer, autoimmunity, inflammation, cardiovascular disease, and neurological conditions, and in the design and development of better medicines for treating these afflictions.

A Dual-Mode Surface Display System for the Maturation and Production of Monoclonal Antibodies in Glyco-Engineered Pichia pastoris

State-of-the-art monoclonal antibody (mAb) discovery methods that utilize surface display techniques in prokaryotic and eukaryotic cells require multiple steps of reformatting and switching of hosts to transition from display to expression. This results in a separation between antibody affinity maturation and full-length mAb production platforms. Here, we report for the first time, a method in Glyco-engineered Pichia pastoris that enables simultaneous surface display and secretion of full-length mAb molecules with human-like N-glycans using the same yeast cell. This paradigm takes advantage of homo-dimerization of the Fc portion of an IgG molecule to a surface-anchored "bait" Fc, which results in targeting functional “half” IgGs to the cell wall of Pichia pastoris without interfering with the secretion of full length mAb. We show the utility of this method in isolating high affinity, well-expressed anti-PCSK9 leads from a designed library that was created by mating yeasts containing either light chain or heavy chain IgG libraries. Coupled with Glyco-engineered Pichia pastoris , this method provides a powerful tool for the discovery and production of therapeutic human mAbs in the same host thus improving drug developability and potentially shortening the discovery time cycle.

Monoclonal antibodies to transmembrane proteins (P4022)

Abstract Transmembrane proteins, including multipass transmembrane proteins like GPCRs and ion channels, are important targets for therapeutic monoclonal antibody (mab) discovery. Therapeutic antibodies to this class of proteins are generally targeted to extracellular domains displayed on the surfaces of living cells. Challenges associated with developing antibodies to this class of targets are small numbers of extracellular amino acids, membrane-dependent protein conformation, difficulty in expression at high levels, high amino acid sequence homology of human and mouse proteins, and post-translational modifications. DNA immunization strategies with full-length constructs and high throughput flow cytometry screening of mab binding to transfected and control cells was used to generate and identify large numbers of mabs to CXCR4 and ADORA2A (GPCRs) and CD20. Panels of mabs were generated for all 3 targets with low numbers of hybridoma fusions. For each target the mab gene sequences were shown to be unique and contain levels of somatic hypermutation comparable to existing benchmark therapeutic antibodies. Functional assays including apoptosis and receptor modulation (calcium flux and cAMP modulation) further demonstrated that the technical approach generated diverse panels of antibodies that exhibit functional activity as good or better than existing benchmark therapeutic antibodies.

Abstract 4325: Monoclonal antibodies to transmembrane proteins.

Abstract Transmembrane proteins, including multipass transmembrane proteins like GPCRs and ion channels, are important targets for therapeutic monoclonal antibody (mab) discovery. Therapeutic antibodies to this class of proteins are generally targeted to extracellular domains displayed on the surfaces of living cells. Challenges associated with developing antibodies to this class of targets are small numbers of extracellular amino acids, membrane-dependent protein conformation, difficulty in expression at high levels, high amino acid sequence homology of human and mouse proteins, and post-translational modifications. DNA immunization strategies with full-length constructs and high throughput flow cytometry screening of mab binding to transfected and control cells was used to generate and identify large numbers of mabs to CXCR4 and ADORA2A (GPCRs) and CD20 (a tetraspan membrane protein). Panels of mabs were generated for all 3 targets with low numbers of hybridoma fusions. For each target the mab gene sequences were shown to be unique and contain levels of somatic hypermutation comparable to existing benchmark therapeutic antibodies. Epitope mapping with mutant proteins identified diverse patterns of reactivity including known and novel specificities. Functional assays including apoptosis and receptor modulation (calcium flux and cAMP modulation) further demonstrated that the technical approach generated diverse panels of antibodies that exhibit functional activity as good or better than existing benchmark therapeutic antibodies Citation Format: Michael C. Brown, Ross Chambers, Dale V. Onisk, Tony R. Joaquim, Lewis J. Stafford, Klaus Lindpaintner, Daniel Keter, James W. Stave. Monoclonal antibodies to transmembrane proteins. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4325. doi:10.1158/1538-7445.AM2013-4325

Development of an Fc-Enhanced Anti–B7-H3 Monoclonal Antibody with Potent Antitumor Activity

The goal of this research was to harness a monoclonal antibody (mAb) discovery platform to identify cell-surface antigens highly expressed on cancer and develop, through Fc optimization, potent mAb therapies toward these tumor-specific antigens. Fifty independent mAbs targeting the cell-surface immunoregulatory B7-H3 protein were obtained through independent intact cell-based immunizations using human tissue progenitor cells, cancer cell lines, or cell lines displaying cancer stem cell properties. Binding studies revealed this natively reactive B7-H3 mAb panel to bind a range of independent B7-H3 epitopes. Immunohistochemical analyses showed that a subset displayed strong reactivity to a broad range of human cancers while exhibiting limited binding to normal human tissues. A B7-H3 mAb displaying exquisite tumor/normal differential binding was selected for humanization and incorporation of an Fc domain modified to enhance effector-mediated antitumor function via increased affinity for the activating receptor CD16A and decreased binding to the inhibitory receptor CD32B. MGA271, the resulting engineered anti-B7-H3 mAb, mediates potent antibody-dependent cellular cytotoxicity against a broad range of tumor cell types. Furthermore, in human CD16A-bearing transgenic mice, MGA271 exhibited potent antitumor activity in B7-H3-expressing xenograft models of renal cell and bladder carcinoma. Toxicology studies carried out in cynomolgus monkeys revealed no significant test article-related safety findings. This data supports evaluation of MGA271 clinical utility in B7-H3-expressing cancer, while validating a combination of a nontarget biased approach of intact cell immunizations and immunohistochemistry to identify novel cancer antigens with Fc-based mAb engineering to enable potent antitumor activity.

Identification of broadly protective human antibodies toPseudomonas aeruginosaexopolysaccharide Psl by phenotypic screening

Pseudomonas aeruginosa is a leading cause of hospital-associated infections in the seriously ill, and the primary agent of chronic lung infections in cystic fibrosis patients. A major obstacle to effective control of P. aeruginosa infections is its intrinsic resistance to most antibiotic classes, which results from chromosomally encoded drug-efflux systems and multiple acquired resistance mechanisms selected by years of aggressive antibiotic therapy. These factors demand new strategies and drugs to prevent and treat P. aeruginosa infections. Herein, we describe a monoclonal antibody (mAb) selection strategy on whole P. aeruginosa cells using single-chain variable fragment phage libraries derived from healthy individuals and patients convalescing from P. aeruginosa infections. This approach enabled identification of mAbs that bind three distinct epitopes on the product of the Psl. This exopolysaccharide is important for P. aeruginosa attachment to mammalian cells, and for the formation and maintenance of biofilms produced by nonmucoid and mucoid P. aeruginosa isolates. Functional screens revealed that mAbs to one epitope exhibit superior activity in opsonophagocytic killing and cell attachment assays, and confer significant protection in multiple animal models. Our results indicate that Psl is an accessible serotype-independent surface feature and promising novel protective antigen for preventing P. aeruginosa infections. Furthermore, our mAb discovery strategy holds promise for application to other bacterial pathogens.

Antibody Discovery Ex Vivo Accelerated by the LacO/LacI Regulatory Network

Monoclonal antibodies (mAbs) can be potent and highly specific therapeutics, diagnostics and research reagents. Nonetheless, mAb discovery using current in vivo or in vitro approaches can be costly and time-consuming, with no guarantee of success. We have established a platform for rapid discovery and optimization of mAbs ex vivo. This DTLacO platform derives from a chicken B cell line that has been engineered to enable rapid selection and seamless maturation of high affinity mAbs. We have validated the DTLacO platform by generation of high affinity and specific mAbs to five cell surface targets, the receptor tyrosine kinases VEGFR2 and TIE2, the glycoprotein TROP2, the small TNF receptor family member FN14, and the G protein-coupled receptor FZD10. mAb discovery is rapid and humanization is straightforward, establishing the utility of the DTLacO platform for identification of mAbs for therapeutic and other applications.

Detecting Antibodies Secreted by Trapped Cells Using Extraordinary Optical Transmission

Isolation of monoclonal (M-) antibodies (Abs) from Ab-secreting cells (ASCs) is impeded by difficulties in identifying the minority of ASCs secreting Ab(s) of interest. We present a novel label-free system that traps ASCs into biocompatible microwells and detects the binding of secreted Ab(s), to a surface-immobilized antigen (Ag), as induced shifts in the extraordinary optical transmission (EOT) spectra through milled nanohole arrays. In this paper, a biotinylated target Ag (Bio-HA and Bio-2F5) is exposed to varying known MAb concentrations (17/9 and 2F5). The mean EOT shift in response to MAb concentration is similar in shape to specific MAb-Ag binding as seen in an ELISA. In another experiment, hybridoma cells secreting 17/9 MAb are trapped in wells inset into poly(dimethyl siloxane) (PDMS) (5-20 cells/trap), to which the nanohole arrays of Bio-HA “Sample” and Bio-2F5 “Ag Control” slides are aligned. Simultaneously, a Bio-HA “Media Control” slide is exposed to MAb-free media. The mean “Sample” shift (3.2 ±0.1 nm) is distinguished from the mean “Ag Control” shift (1.2 ±0.4 nm), but indistinguishable from the mean “Media Control” shift (3.6 ±0.3 nm). We have made significant progress in detecting Ab(s) secreted from trapped ASCs. With further development, our device could identify ASCs of interest rapidly, streamlining therapeutic MAb discovery.

Monoclonal antibodies: a morphing landscape for therapeutics

AbstractThe concept of using antibodies as therapeutics to cure human diseases was postulated nearly 100 years ago by Paul Ehrlich and subsequently enabled by the discovery of hybridoma technology by Kohler and Milstein in 1975. While the use of monoclonal antibodies (mAbs) as drugs that can specifically target a disease‐associated antigen is compelling, it has taken a quarter century for these molecules to be adopted as bona fide therapeutic agents. Despite their slow pursuit in drug development during the pioneering years, it is now estimated that there are nearly 500 mAb‐based therapies in development. Major factors that have influenced the acceptance of monoclonal antibodies as therapeutics include their drug safety profiles, technological advancements for facilitating mAb discovery and development, and market success. Early on, it was demonstrated that antibodies could elicit clinical benefit by antagonizing a specific antigen without the common side effects that are prevalent with small chemical entities due to their nonspecific effects on homeostatic biochemical pathways. In addition, the significant technological advances that the biotechnology industry has established for developing and producing monoclonal antibodies at commercial scale in a more efficient and cost‐effective manner has broadly enabled their use as therapeutics. However, despite the beneficial pharmacologic advantages and technological advances, it has been the sheer market success that monoclonal antibody products have achieved over the past few years that has propelled their vast pursuit by the biopharmaceutical industry in light of their value‐creating potential. Here we provide an overview of the monoclonal antibody industry and discuss evolving technologies and strategies that are being pursued to overcome challenges in the changing marketplace. Drug Dev. Res. 67:781–789, 2006. © 2007 Wiley‐Liss, Inc.