Evaluation of physicochemical and functional similarity of a new CHO derived anti-EGFR antibody P-mAb to its reference medicinal product

Epidermal growth factor receptor (EGFR) is the primary target for the treatment of colorectal cancer, the third most diagnosed cancer worldwide. In recent years, regulatory changes have facilitated the approval of biosimilars aimed to bring more access to biologics to patients. However, it has also expended the requirements of non-clinical characterisation data using state-of-the-art and orthogonal methodologies to demonstrate similarity between proposed biologic and its reference medicinal product (RMP). The current study was aimed to develop a stable CHO-S cell line producing panitumumab biosimilar candidate, P-mAb, a fully human IgG2 anti-EGFR monoclonal antibody and assess its physicochemical and functional similarity with RMP, Vectibix.
The single-cell clone from stably transfected CHO-S cell pools was used for the production of P-mAb. This was followed by purification and comparative physicochemical and biological characterisation of P-mAb and RMP using SDS-PAGE, LC/MS, MALDI, MS/MS, CD spectrometry, DSF, SAXS, ITF, MTT assay and binding affinity. SAXS and MST assays are being used for first time in biosimilarity analysis of therapeutic monoclonal antibody. The results of structural and functional analysis of anti-EGFR P-mAb, produced by stable CHO-S cell line revealed high similarity between P-mAb and RMP, vectibix, thus providing the scientific basis of its potential for therapeutic applications.

Defects in an orthorhombic MoAlB MAB phase thin film grown at moderate synthesis temperature

Here, we report on atomic scale characterization of various defects in a MoAlB (MAB) phase thin film grown by DC sputtering at a synthesis temperature of 700 °C. Aberration-corrected scanning transmission electron microscopy reveals the formation of an intergrown metastable Mo3Al2B4 phase accompanied by thermally stable 90° twist boundaries, coexisting within the pristine MoAlB matrix. The concurrent formation of these structural defects in the MoAlB matrix can be rationalized based on minute differences in formation enthalpies as shown via density functional theory calculations.
The specific structural nature of both the twist boundary and compositional defect (Mo3Al2B4) in a MoAlB matrix is hitherto unreported in literature. Apart from these defects, faceted grain boundaries are observed. In the vicinity of amorphous AlOx regions, Al is deintercalated and a 2D MoB MBene phase is formed as reported before. Besides these amorphous AlOx regions, a few nanometer-sized 3D MoB clusters are found. The advancement of aberration-corrected scanning transmission electron microscopy significantly improves characterization from 1D to 3D defects which is important for thin film materials design for the moderate synthesis temperature range. The reported defects might play an important role in the formation of 2D MoB MBenes.

Immune checkpoint blockade with anti-programmed cell death 1 (PD-1) monoclonal antibody (mAb) cemiplimab: ongoing and future perspectives in rare genital cancers treatment

Cemiplimab is a highly potent, hinge-stabilized human IgG4 monoclonal antibody (mAb) targeting programmed cell death 1 (PD-1) receptor approved for patients with locally advanced or metastatic cutaneous squamous cell carcinoma (SCC) who are not candidates for curative surgery or curative radiation. Recently, the phase 3 trial EMPOWER-Cervical 1 has investigated cemiplimab in patients with recurrent/metastatic cervical cancer. At interim analysis, overall survival (OS), progression free survival (PFS) and objective response rate (ORR) in overall and SCC populations favored cemiplimab over single agent chemotherapy.Cervical SCCs are the first for incidence among Human Papilloma Virus (HPV) related neoplasms and are highly correlated (about 95%) with the viral infection. Similarly, penile and vulvar SCC may develop on chronic HPV infections or on dermatological chronic conditions (ie, lichen).
The molecular and viral similarities between external genital SCC and SCC originating from the cervical epithelium could be the rationale for using cemiplimab to treat locally advanced or metastatic penile and vulvar SCC as well. Some retrospective data have shown that cemiplimab may provide objective response and clinical benefit to some patients with penile or vulvar SCC and is overall safe to utilize in this population. Given the complexity of the immune activation and the considerable variability in tumor biology across patients and tumor types, the identification of biomarkers to warrant patient selection needs to be further explored. Ongoing clinical trials will hopefully shed light on the treatment paradigm of these rare tumors too, with special regard to the ideal combination and sequencing of immunotherapeutic strategies.

Trispecific antibodies produced from mAb 2 pairs by controlled Fab-arm exchange

Bispecific antibodies and antibody fragments are therapeutics of growing importance. They are clinically applied for effector cell engagement, enhanced targeting selectivity, addressing of multiple cellular pathways and active transfer of certain activities into difficult-to-reach compartments. These functionalities could profit from a third antigen specificity. In this work we have employed symmetrical bispecific parental antibodies of mAb2 format, which feature a novel antigen binding site in the CH2 constructs.

Custom Production of Monoclonal antibodies (immunization, ELISA Kit, fusion, screening, Cloning of up to 3 clones)

MAB-1 Alpha Diagnostics 1 10403 EUR

Anti-?-Actin (BA3R) Loading Control Monoclonal Antibody

ABP-MAB-BL002 Allele Biotech 100 ug Ask for price

Anti-DYKDDDDK (FLAG) Tag (FG4R) Monoclonal Antibody

ABP-MAB-DT006 Allele Biotech 100 ug Ask for price

Anti-ERK1 (E32) Signal Transduction Monoclonal Antibody

ABP-MAB-ES001 Allele Biotech 100 ug Ask for price

Anti-ERK1 (E19) Signal Transduction Monoclonal Antibody

ABP-MAB-ES002 Allele Biotech 100 ug Ask for price

Anti-ERK1/2 (E31R) Signal Transduction Monoclonal Antibody

ABP-MAB-ES003 Allele Biotech 100 ug Ask for price

Anti-GAPDH (GA1R) Loading Control Monoclonal Antibody

ABP-MAB-GL001 Allele Biotech 100 ug Ask for price

Anti-GST Tag (GST.B6 / G2R) Monoclonal Antibody

ABP-MAB-GT003 Allele Biotech 100 ug Ask for price

Anti-GFP (GF28R) Tag monoclonal antibody

ABP-MAB-GT007 Allele Biotech 100 ug Ask for price

Anti-His Tag (HIS.H8 / EH158) Monoclonal Antibody

ABP-MAB-HT001 Allele Biotech 100 ug Ask for price

Anti-HA Tag (HA.C5 / C10) Monoclonal Antibody

ABP-MAB-HT002 Allele Biotech 100 ug Ask for price

Anti-Myc Tag (Myc.A7 / M19) Monoclonal Antibody

ABP-MAB-MT005 Allele Biotech 100 ug Ask for price

Anti-RFP (Red Fluorescent Protein) Tag (RF5R) Monoclonal Antibody

ABP-MAB-RT008 Allele Biotech 100 ug Ask for price

Anti-V5 Tag (E10 / V4RR) Monoclonal Antibody

ABP-MAB-VT004 Allele Biotech 100 ug Ask for price

Monkey IFN-γ ELISPOT kit (mAb + mAb biot)

CT121-PB2 U-CyTech 2-plate 415 EUR

Monkey IFN-γ ELISPOT kit (mAb + mAb biot)

CT121-PB5 U-CyTech 5-plate 568 EUR

Monkey IFN-γ ELISPOT kit (mAb + mAb biot)

CT121-PR2 U-CyTech 2-plate 415 EUR

Monkey IFN-γ ELISPOT kit (mAb + mAb biot)

CT121-PR5 U-CyTech 5-plate 556 EUR

Monkey IFN-γ ELISPOT kit (mAb + mAb biot)

CT121-T2 U-CyTech 2-plate 360 EUR

Monkey IFN-γ ELISPOT kit (mAb + mAb biot)

CT121-T5 U-CyTech 5-plate 579 EUR

ACTB Mouse mAb

AC004 Abclonal 50 ul 176 EUR

ACTB Rabbit mAb

AC026 Abclonal 50 ul 204 EUR

Development of an efficient mAb quantification assay by LC-MS/MS using rapid on-bead digestion

The use of monoclonal antibody (mAb) therapeutics is increasing rapidly, but mAb concentrations vary widely between individuals and might subsequently affect mAb exposure and treatment response. Precision medicine has gained much attention in recent years, but little is known about the personalized dosage of mAb therapeutics. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been demonstrated as a selective and sensitive approach to quantify mAb therapeutics in biological samples, but current methods to quantify mAbs are usually time-consuming and require tedious sample preparation.
This study developed an efficient LC-MS/MS method using an on-bead trypsin digestion procedure at a higher digestion temperature. Five mAbs, bevacizumab, evolocumab, nivolumab, pembrolizumab, and trastuzumab, used for treating different diseases, were selected for method development. Tocilizumab was selected as the internal standard. The result of the on-bead digestion protocol was compared to the conventional low-pH elution method, and it showed better sensitivity and reproducibility for most mAbs. The optimized on-bead digestion protocol used 75 μL of digestion buffer at 60 °C for a 60 min digestion.
The calibration curve was generated from 10 to 200 μg mL-1. The accuracies at the three QC levels of the 5 mAbs were all within 94.5 ± 5.2% to 111.6 ± 3.7%. The repeatability and intermediate precision of the 5 mAbs were all lower than 6.1 and 9.5% RSD, respectively. The newly developed method was successfully applied to quantify trastuzumab in six breast cancer patients under different treatment cycles, and the concentrations ranged from 66.4 to 173.2 μg mL-1. In conclusion, the developed method is more efficient and more practical for real-world analysis of a large number of clinical samples, it could be used for routine therapeutic drug monitoring, and it could contribute to personalized mAb treatment.

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