Development of therapeutic antibodies for the treatment of diseases

Abstract

Since the first monoclonal antibody drug, muromonab-CD3, was approved for marketing in 1986, 165 antibody drugs have been approved or are under regulatory review worldwide. With the approval of new drugs for treating a wide range of diseases, including cancer and autoimmune and metabolic disorders, the therapeutic antibody drug market has experienced explosive growth. Monoclonal antibodies have been sought after by many biopharmaceutical companies and scientific research institutes due to their high specificity, strong targeting abilities, low toxicity, side effects, and high development success rate. The related industries and markets are growing rapidly, and therapeutic antibodies are one of the most important research and development areas in the field of biology and medicine. In recent years, great progress has been made in the key technologies and theoretical innovations provided by therapeutic antibodies, including antibody-drug conjugates, antibody-conjugated nuclides, bispecific antibodies, nanobodies, and other antibody analogs. Additionally, therapeutic antibodies can be combined with technologies used in other fields to create new cross-fields, such as chimeric antigen receptor T cells (CAR-T), CAR-natural killer cells (CAR-NK), and other cell therapy. This review summarizes the latest approved or in regulatory review therapeutic antibodies that have been approved or that are under regulatory review worldwide, as well as clinical research on these approaches and their development, and outlines antibody discovery strategies that have emerged during the development of therapeutic antibodies, such as hybridoma technology, phage display, preparation of fully human antibody from transgenic mice, single B-cell antibody technology, and artificial intelligence-assisted antibody discovery.

Keywords: AI-assisted antibody discovery; Antibody drugs; Immunotherapy; Phage display libraries; Single B-cell; Transgenic mice.

Fig. 1

Primary indications for antibody therapeutics are approved across the globe and in late-stage clinical studies sponsored by commercial firms. a Primary indications for antibody therapeutics are approved across the globe. Immune-mediated disorders category includes asthma, systemic lupus erythematosus, rheumatoid arthritis, etc.; the genetic disorders are Muckle-Wells syndrome, X-linked hypophosphatemia, hereditary angioedema attacks, and homozygous familial hypercholesterolemia. Figure based on data publicly available (www.antibodysociety.org/antibody-therapeutics-product-data/.) as of July 1, 2022, total = 165. b Primary indications for antibody therapeutics in late-stage clinical studies. “Late-stage” is defined as pivotal Phase II, Phase II/III, or Phase III studies. Immune-mediated disorders category includes allergy and asthma; respiratory includes chronic obstructive pulmonary disease. Figure based on data publicly available (www.antibodysociety.org/antibody-therapeutics-product-data/.) as of May 1, 2022, total = 145

Fig. 2

Targets for antibody therapeutics approved or in regulatory review globally for diseases. a targets for cancer and b targets for non-cancer. TSLP, thymic stromal lymphopoietin. Figure based on data publicly available (www.antibodysociety.org/antibody-therapeutics-product-data/.) as of July 1, 2022, total = 165

Fig. 3

Histogram of the number of mAbs for the top ten targets and R&D companies. a The top ten targets of mAbs approved to market for use from 2021. Data were collected from January 1, 2021, to August 1, 2022. b The top ten institutions and the distribution of their drug R&D stages. R&D, research and development. Figure based on data publicly available as of August 1, 2022, and available at https://pharmsnap.zhihuiya.com/

Fig. 4

Timeline of historical bispecific antibody developments and first approval for market. This timeline demonstrates key points in the development of bispecific antibodies. BiKEs, bispecific killer engagers; DVD-Ig, dual-variable-domain immunoglobulin

Fig. 5

Schematic overview of mAb, ADC, BsAb, and antibody fragments (Fab, scFv, VHH). a Antibody humanization from the murine antibody (green domain) to human antibody (orange domain) and associated suffixes. The chimeric mAb: the variable region is of murine origin, and the rest of the chain is of human origin. Humanized mAb: only includes the hypervariable segment of murine origin. CH: domains of the constant region of the heavy chain; CL: constant domain of the light chain; VH: variable domain of the heavy chain; VL: variable domain of the light chain. b Original antibody includes variable regions, also called VH and VL (red domain), and the constant region (blue domain). ADC comprises a mAb connected to a cytotoxic payload via an appropriate linker. BsAb consists of two linked antigen-binding fragments (red and gray domains) with two major formats: IgG-like BsAb and non-IgG-like BsAb; Fab consists of the light chain (VL + CL) and the domains of the heavy chain (VH and CH1). scFv is composed of the VH and VL joined by a short flexible polypeptide linker. VHH only contains one heavy chain variable region

Fig. 6

Technologies for the development of therapeutic antibodies. a Mouse hybridoma technique. Mice are immunized with desired antigens to induce high immune titers. Myeloma cells and harvested splenocytes are fused to produce hybridomas that persist in secreting antibodies. A chimeric or humanized antibody is then created after the screening has been completed. b Phage display. A library of human antibodies is constructed and fused to the gene that encodes the pIII coat protein on the surface of the phage. After binding the target antigen of bio-panning, positive phage clones are screened and then DNA sequences are analyzed to construct and express human IgG. c Transgenic mouse. The mice are genetically engineered to contain one or more human immunoglobulin loci which are capable of undergoing gene rearrangement and gene conversion in the transgenic mice to produce diversified human immunoglobulins. Then the fully human antibody screen approach is similar to the mouse hybridoma technique. d The single B-cell technique. From infected or immunization donors, PBMCs are prepared for the isolation of suitable B cells by flow cytometry. Following the RT-PCR, VH and VL information of each B cell informs the generation of human mAbs