According to Research and Markets, the global market for Fc and glycoengineered antibodies is projected to be worth US$38.8 billion in 2024. Over the next decade, the growth in opportunities for drug developers is expected to be driven by an increasing patient population and rising demand for these advanced antibody therapies.
Glycoengineering, the process of modifying glycan structures on proteins to enhance their functions, plays a crucial role in improving antibody efficacy. It is particularly significant for modifying the N-glycans on the Fc domain of immunoglobulin G (IgG), which influence key immune responses. This field has advanced significantly, with strategies such as mammalian cell expression system engineering, chemo-enzymatic techniques, and yeast-based approaches enabling precise glycan remodeling. These methods improve the homogeneity of glycans, simplifying the study of structure-activity relationships and enhancing therapeutic efficacy while minimizing side effects. Additionally, glycoengineering has been pivotal in developing antibody-drug conjugates (ADCs), offering new opportunities to optimize IgG-based therapies.
DOI:10.1146/annurev-biochem-062917-012911
On April 30, 2024, China’s NMPA (National Medical Products Administration) approved Benmelstobart (Andewei, TQB2450), a humanized anti-PD-L1 IgG1κ monoclonal antibody that was Fc engineered to reduce effector function (D265A) by Chia Tai Tianqing Pharmaceutical Group Co., Ltd. Other glycoengineered antibodies that were previously approved include AstraZeneca’s Benralizumab (Fasenra), Genentech’s Obinutuzumab (Gazyva), Incyte’s Tafasitamab (Monjuvi), and Amgen’s Inebilizumab (Uplizna).
A recent review highlights the role of glycosylation in monoclonal antibodies (mAbs) for cancer therapy, emphasizing its impact on efficacy, safety, and pharmacokinetics. Combining genetic and metabolic glycoengineering has enabled precise tuning of glycoprofiles, improving antibody-dependent cell-mediated cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and target specificity. Advances in combinatory glycoengineering, such as afucosylation and glycan modifications, have optimized therapeutic outcomes in clinical trials, including immune checkpoint therapies targeting PD-1/PD-L1 glycosylation. Emerging strategies and high-tech tools for glycan detection and analysis promise to revolutionize biotherapeutics, enabling the production of safer, customized glycoproteins with enhanced efficacy.
Various strategies for glycoengineering antibodies have been developed, including from a recent paper describing EndoSz-D234M, a mutant endo-β-N-acetylglucosaminidase, as a platform for enhancing the therapeutic efficacy of mAbs through improved transglycosylation activity. It remodels diverse glycans on mAbs, producing homogeneous antibodies with 3–26-fold increased ADCC activity. High-resolution crystal structures of EndoSz-D234M, including its complex with a G2S2-oxazoline intermediate, reveal the "oxa-hole," a critical structural feature stabilizing intermediates and catalyzing transglycosylation. Key interactions, such as hydrogen bonding in the oxa-hole and contributions from loop structures, elucidate the mechanism of substrate selectivity and activity. Mutational analyses confirm the roles of specific residues, offering insights for further engineering to improve antibody-specific glycosynthesis.
DOI: 10.1021/jacsau.4c00004
Enhanced Functionality
A recent study introduces αPD-1-(iRGD)2, a glycoengineered PD-1 antibody-iRGD peptide conjugate, as a novel immunotherapy for cancer. By combining enhanced tumor penetration with dual targeting of tumor cells and PD-1+ T cells, αPD-1-(iRGD)2 activates and amplifies tumor-specific T cells while maintaining biosafety. In mouse models, it effectively reduced tumor growth, remodeled the tumor microenvironment (TME), and expanded a subset of CD8+ tumor-infiltrating lymphocytes (TILs) expressing stem and memory-associated genes like Tcf7 and Il7r. Unlike traditional BiTEs and scFv-based therapeutics, αPD-1-(iRGD)2 offers improved solubility, stability, and circulation half-life, addressing the challenges of poor drug uptake and immune infiltration in solid tumors. This platform exemplifies a promising therapeutic innovation for cancer immunotherapy, combining antibody functionality with targeted peptide delivery to overcome limitations of current approaches.
Meanwhile, another study developed glycoengineered rice cell lines using CRISPR/Cas9 to eliminate plant-specific N-glycans and produce trastuzumab (TMab) with enhanced efficacy. The resulting P-TMab showed improved anti-cancer effects, including stronger inhibition of BT-474 cancer cell proliferation, enhanced binding to the FcγRIIIa-F158 variant, and greater antibody-dependent cellular cytotoxicity (ADCC) than TMab. P-TMab also demonstrated better tumor uptake and less liver accumulation in xenograft assays.
DOI:10.1016/j.xcrm.2024.101590
On another focus, this study presents a novel strategy for the direct glycosylation analysis of intact monoclonal antibodies (mAbs) by combining two mass spectrometry (MS) techniques: direct infusion ESI MS for intact glycoform analysis and MALDI-in-source decay (ISD) FT-ICR MS for direct glycan analysis. This combined approach provides profiles glycosylation in mAbs without the slightly more time-consuming enzymatic treatments or separation techniques. The MALDI-ISD MS method can give insights into glycosylation micro-heterogeneity, detecting glycans such as Man5 and G0 that were otherwise missed in intact protein analysis. It provides complementary information to traditional methods, enabling the rapid comparison of glycoforms and enhancing the analysis of glycoengineered mAbs.
The antibody industry is increasingly focused on glycoengineering as a strategy to improve therapeutic efficacy and specificity. Recent collaborations, such as the one between OBI Pharma and GlyTech, Inc., highlight the growing emphasis on glycan production for antibody-drug conjugates (ADCs). As glycosylation plays a significant role in enhancing antibody-dependent cellular cytotoxicity (ADCC) and optimizing pharmacokinetics, companies are investing in advanced technologies to control glycosylation patterns. The integration of high-throughput glycosylation profiling and gene editing is expected to further accelerate the development of next-generation antibodies, offering more effective treatments for oncology and other therapeutic areas. The industry's push toward glycoengineering, supported by strategic collaborations and technological advancements, underscores the importance of glycan optimization in the future of antibody therapeutics.
