|
|
- A novel humanized Chi3l1 blocking antibody attenuates
acetaminophen-induced liver injury in mice
Pages: 1 - 12
Abstract: AbstractAcetaminophen (APAP) overdose is a leading cause of acute liver injury in the USA. The chitinase 3-like-1 (Chi3l1) protein contributes to APAP-induced liver injury (AILI) by promoting hepatic platelet recruitment. Here, we report the development of a Chi3l1-targeting antibody as a potential therapy for AILI. By immunizing a rabbit successively with the human and mouse Chi3l1 proteins, we isolated cross-reactive monoclonal antibodies (mAbs) from single memory B cells. One of the human and mouse Chi3l1 cross-reactive mAbs was humanized and characterized in both in vitro and in vivo biophysical and biological assays. X-ray crystallographic analysis of the lead antibody C59 in complex with the human Chi3l1 protein revealed that the kappa light contributes to majority of the antibody–antigen interaction; and that C59 binds to the 4α-5β loop and 4α-helix of Chi3l1, which is a functional epitope and hotspot for the development of Chi3l1 blocking antibodies. We humanized the C59 antibody by complementarity-determining region grafting and kappa chain framework region reverse mutations. The humanized C59 antibody exhibited similar efficacy as the parental rabbit antibody C59 in attenuating AILI in vivo. Our findings validate Chi3l1 as a potential drug target for AILI and provide proof of concept of developing Chi3l1 blocking antibody as a therapy for the treatment of AILI.
PubDate: Mon, 07 Nov 2022 00:00:00 GMT
DOI: 10.1093/abt/tbac027
Issue No: Vol. 6, No. 1 (2022)
- Developability assessment at early-stage discovery to enable development
of antibody-derived therapeutics
Pages: 13 - 29
Abstract: AbstractDevelopability refers to the likelihood that an antibody candidate will become a manufacturable, safe and efficacious drug. Although the safety and efficacy of a drug candidate will be well considered by sponsors and regulatory agencies, developability in the narrow sense can be defined as the likelihood that an antibody candidate will go smoothly through the chemistry, manufacturing and control (CMC) process at a reasonable cost and within a reasonable timeline. Developability in this sense is the focus of this review. To lower the risk that an antibody candidate with poor developability will move to the CMC stage, the candidate’s developability-related properties should be screened, assessed and optimized as early as possible. Assessment of developability at the early discovery stage should be performed in a rapid and high-throughput manner while consuming small amounts of testing materials. In addition to monoclonal antibodies, bispecific antibodies, multispecific antibodies and antibody-drug conjugates, as the derivatives of monoclonal antibodies, should also be assessed for developability. Moreover, we propose that the criterion of developability is relative: expected clinical indication, and the dosage and administration route of the antibody could affect this criterion. We also recommend a general screening process during the early discovery stage of antibody-derived therapeutics. With the advance of artificial intelligence-aided prediction of protein structures and features, computational tools can be used to predict, screen and optimize the developability of antibody candidates and greatly reduce the risk of moving a suboptimal candidate to the development stage.
PubDate: Fri, 11 Nov 2022 00:00:00 GMT
DOI: 10.1093/abt/tbac029
Issue No: Vol. 6, No. 1 (2022)
- Ceramic hydroxyapatite chromatography plays a critical role in bispecific
antibody purification process for impurity removal
Pages: 30 - 37
Abstract: AbstractBackgroundSignificant challenges exist in downstream purification of bispecific antibodies (BsAbs) due to the complexity of BsAb architecture. A unique panel of mispaired species can result in a higher level of product-related impurities. In addition to process-related impurities such as host cell proteins (HCPs) and residual DNA (resDNA), these product-related impurities must be separated from the targeted BsAb product to achieve high purity. Therefore, development of an efficient and robust chromatography purification process is essential to ensure the safety, quality, purity and efficacy of BsAb products that consequently meet regulatory requirements for clinical trials and commercialization.MethodsWe have developed a robust downstream BsAb process consisting of a mixed-mode ceramic hydroxyapatite (CHT) chromatography step, which offers unique separation capabilities tailored to BsAbs, and assessed impurity clearance.ResultsWe demonstrate that the CHT chromatography column provides additional clearance of low molecular weight (LMW) and high molecular weight (HMW) species that cannot be separated by other chromatography columns such as ion exchange for a particular BsAb, resulting in ≥98% CE-SDS (non-reduced) purity. Moreover, through Polysorbate-80 (PS-80) spiking and LC–MS HCP assessments, we reveal complete clearance of potential PS-80-degrading HCP populations in the CHT eluate product pool.ConclusionsIn summary, these results demonstrate that CHT mixed-mode chromatography plays an important role in separation of product- and process-related impurities in the BsAb downstream process.
PubDate: Sat, 19 Nov 2022 00:00:00 GMT
DOI: 10.1093/abt/tbac030
Issue No: Vol. 6, No. 1 (2022)
- Preclinical evaluation of IAP0971, a novel immunocytokine that binds
specifically to PD1 and fuses IL15/IL15Rα complex
Pages: 38 - 48
Abstract: AbstractBackgroundCurrently, cytokine therapy for cancer has demonstrated efficacy in certain diseases but is generally accompanied by severe toxicity. The field of antibody-cytokine fusion proteins (immunocytokines) arose to target these effector molecules to the tumor microenvironment to expand the therapeutic window of cytokine therapy. Therefore, we have developed a novel immunocytokine that binds specifically to programmed death 1 (PD1) and fuses IL15/IL15Rα complex (referred to as IAP0971) for cancer immunotherapy.MethodsWe report here the making of IAP0971, a novel immunocytokine that binds specifically to PD1 and fuses IL15/IL15Rα complex, and preclinical characterization including pharmacology, pharmacodynamics, pharmacokinetics and toxicology, and discuss its potential as a novel agent for treating patients with advanced malignant tumors.ResultsIAP0971 bound to human IL2/15Rβ proteins specifically and blocked PD1/PDL1 signaling transduction pathway. IAP0971 promoted the proliferation of CD8 + T cells and natural killer T (NKT) cells, and further activated NK cells to kill tumor cells validated by in vitro assays. In an hPD1 knock-in mouse model, IAP0971 showed potent anti-tumor activity. Preclinical studies in non-human primates following single or repeated dosing of IAP0971 showed favorable pharmacokinetics and well-tolerated toxicology profile.ConclusionIAP0971 has demonstrated a favorable safety profile and potent anti-tumor activities in vivo. A Phase I/IIa clinical trial to evaluate the safety, tolerability and preliminary efficacy of IAP0971 in patients with advanced malignant tumors is on-going (NCT05396391).
PubDate: Thu, 17 Nov 2022 00:00:00 GMT
DOI: 10.1093/abt/tbac031
Issue No: Vol. 6, No. 1 (2022)
- Comparative Assessment of the Binding and Neutralisation Activity of
Bispecific Antibodies Against SARS-CoV-2 Variants
Pages: 49 - 58
Abstract: AbstractBackgroundNeutralising antibodies against SARS-CoV-2 are a vital component in the fight against COVID-19 pandemic, having the potential of both therapeutic and prophylactic applications. Bispecific antibodies (BsAbs) against SARS-CoV-2 are particularly promising, given their ability to bind simultaneously to two distinct sites of the receptor-binding domain (RBD) of the viral spike protein. Such antibodies are complex molecules associated with multi-faceted mechanisms of action that require appropriate bioassays to ensure product quality and manufacturing consistency.MethodsWe developed procedures for biolayer interferometry (BLI) and a cell-based virus neutralisation assay, the focus reduction neutralisation test (FRNT). Using both assays, we tested a panel of five BsAbs against different spike variants (Ancestral, Delta and Omicron) to evaluate the use of these analytical methods in assessing binding and neutralisation activities of anti-SARS-CoV-2 therapeutics.ResultsWe found comparable trends between BLI-derived binding affinity and FRNT-based virus neutralisation activity. Antibodies that displayed high binding affinity against a variant were often followed by potent neutralisation at lower concentrations, whereas those with low binding affinity also demonstrated reduced neutralisation activity.ConclusionThe results support the utility of BLI and FRNT assays in measuring variant-specific binding and virus neutralisation activity of anti-SARS-CoV-2 antibodies.
PubDate: Thu, 29 Dec 2022 00:00:00 GMT
DOI: 10.1093/abt/tbac032
Issue No: Vol. 6, No. 1 (2022)
|
Open Access journal
