Development of therapeutic antibodies for the treatment of diseases

Therapeutic opportunities to manage COVID-19/SARS-CoV-2 infection: Present and future

A severe form of respiratory disease - COVID-19, caused by SARS-CoV-2 infection, has evolved into a pandemic resulting in significant morbidity and mortality. The unabated spread of the disease is due to lack of vaccine and effective therapeutic agents against this novel virus. Hence, the situation demands an immediate need to explore all the plausible therapeutic and prophylactic strategies that can be made available to stem the spread of the disease. Towards this effort, the current review outlines the key aspects of the pathobiology associated with the morbidity and mortality in COVID-19 patients, which includes a viral response phase and an exaggerated host response phase. The review also summarizes therapeutic agents that are currently being explored along with those with potential for consideration. The broad groups of therapeutic agents discussed include those that: (i) block viral entry to host cells, (ii) block viral replication and survival in host cells, and (iii) dampen exaggerated host immune response. The various kinds of pharmaceutical prophylactic options that may be followed to prevent COVID-19 have also been discussed.

Developing therapeutic monoclonal antibodies at pandemic pace

The time from discovery to proof-of-concept trials could be reduced to 5–6 months from a traditional timeline of 10–12 months.

Molecular Interaction Characterization Strategies for the Development of New Biotherapeutic Antibody Modalities

The characterization of target binding interactions is critical at each stage of antibody therapeutic development. During early development, it is important to design fit-for-purpose in vitro molecular interaction characterization (MIC) assays that accurately determine the binding kinetics and the affinity of therapeutic antibodies for their targets. Such information enables PK/PD (pharmacokinetics/pharmacodynamics) modeling, estimation of dosing regimens, and assessment of potency. While binding kinetics and affinities seem to be readily obtained, there is little discussion in the literature on how the information should be generated and used in a systematic manner along with other approaches to enable key drug development decisions. The introduction of new antibody modalities poses unique challenges to the development of MIC assays and further increases the need to discuss the impact of developing context-appropriate MIC assays to enable key decision making for these programs. In this paper, we discuss for the first time the challenges encountered when developing MIC assays supporting new antibody modalities. Additionally, through the presentation of several real case studies, we provide strategies to overcome these challenges to enable investigational new drug (IND) filings.

Development of an intensified fed-batch production platform with doubled titers using N-1 perfusion seed for cell culture manufacturing

The goal of cell culture process intensification is to increase volumetric productivity, generally by increasing viable cell density (VCD), cell specific productivity or production bioreactor utilization in manufacturing. In our previous study, process intensification in fed-batch production with higher titer or shorter duration was demonstrated by increasing the inoculation seeding density (SD) from ~ 0.6 (Process A) to 3–6 × 106 cells/mL (Process B) in combination with media enrichment. In this study, we further increased SD to 10–20 × 106 cells/mL (Process C) using perfusion N-1 seed cultures, which increased titers already at industrially relevant levels by 100% in 10–14 day bioreactor durations for four different mAb-expressing CHO cell lines. Redesigned basal and feed media were critical for maintaining higher VCD and cell specific productivity during the entire production duration, while medium enrichment, feeding strategies and temperature shift optimization to accommodate high VCDs were also important. The intensified Process C was successfully scaled up in 500-L bioreactors for 3 of the 4 mAbs, and quality attributes were similar to the corresponding Process A or Process B at 1000-L scale. The fed-batch process intensification strategies developed in this study could be applied for manufacturing of other mAbs using CHO and other host cells.

Phage Display Derived Monoclonal Antibodies: From Bench to Bedside

Monoclonal antibodies (mAbs) have become one of the most important classes of biopharmaceutical products, and they continue to dominate the universe of biopharmaceutical markets in terms of approval and sales. They are the most profitable single product class, where they represent six of the top ten selling drugs. At the beginning of the 1990s, an in vitro antibody selection technology known as antibody phage display was developed by John McCafferty and Sir. Gregory Winter that enabled the discovery of human antibodies for diverse applications, particularly antibody-based drugs. They created combinatorial antibody libraries on filamentous phage to be utilized for generating antigen specific antibodies in a matter of weeks. Since then, more than 70 phage-derived antibodies entered clinical studies and 14 of them have been approved. These antibodies are indicated for cancer, and non-cancer medical conditions, such as inflammatory, optical, infectious, or immunological diseases. This review will illustrate the utility of phage display as a powerful platform for therapeutic antibodies discovery and describe in detail all the approved mAbs derived from phage display.

Protein A-mesoporous silica composites for chromatographic purification of immunoglobulin G

Protein A-mesoporous silica composites were synthesized by covalently coupling protein A with installed carbonyl imidazole moieties inside the column and used for the chromatographic purification of immunoglobulin G.

Potent neutralization of SARS-CoV-2 by human antibody heavy-chain variable domains isolated from a large library with a new stable scaffold

Effective therapies are urgently needed for COVID-19. Here we describe the identification of a new stable human immunoglobulin G1 heavy-chain variable (VH) domain scaffold that was used for the construction of a large library, lCAT6, of engineered human VHs. This library was panned against the receptor-binding domain (RBD) of the SARS-CoV-2 spike (S) glycoprotein. Two VH domains (VH ab6 and VH m397) were selected and fused to Fc for increased half-life in circulation. The VH-Fc ab6 and m397 specifically neutralized SARS-CoV-2 with high potencies (50% neutralization at 0.35 µg/ml and 1.5 µg/ml, respectively) as measured by two independent replication-competent virus neutralization assays. Ab6 and m397 competed with ACE2 for binding to RBD, suggesting a competitive mechanism of virus neutralization. These VH domains may have potential applications for prophylaxis and therapy of COVID-19 alone or in combination, as well as for diagnosis and as tools for research.