ABSTRACT
The in vitro transcribed (IVT) mRNA technology has progressed rapidly and the application of mRNA vaccines in the COVID-19 pandemic made it become the most talked-about topic. Compared with protein drugs, IVT mRNA has a lower cost; it can be modular produced and its sequence can be modified easily, so it has a broad application prospect. However, due to its short history, mRNA drugs face the problem of lacking sufficient clinical data, and there is no quality control standard for mRNA drugs except mRNA vaccines. We overview the sequence design, delivery vectors, administration, application prospect and safety considerations of mRNA drugs. We also discussed the quality control of mRNA drugs briefly.
ABSTRACT
A method to measure the antibody-dependent cell-mediated phagocytosis (ADCP) potency of anti-CD38 mAb was developed based on design of experiment (DoE) with a Jurkat/NFAT/CD32a-FcεRIγ transgenic cell line as the effector cell, the Daudi cell line as the target cells, and luciferase as the detection system. The DoE method was used for optimization of experimental parameters and methodological validation. The results show that anti-CD38 mAb exhibits a dose-response relationship with the following four-parameter equation: y = (A - D) / [1 + (x / C)B] + D. Several experimental parameters were optimized by statistical experimental design and determined as follows: the working concentration of anti-CD38 mAb was 800-20.81 ng·mL-1, the density of the target cells was 7.5×104 per well, and the density of effector cells was 2.5×104 per well, with an induction time of 6 h. The method showed good specificity. The recovery rate for samples from 5 different groups showed that the relative potencies of anti-CD38 mAb were (59.97 ± 4.74) %, (82.44 ± 5.15) %, (110.69 ± 11.71) %, (129.23 ± 5.22)% and (162.15 ± 3.66) %. The recoveries ranged from 103% to 120% and the RSDs of the above results were all less than 11%. The linear detection range was 50%-150%. Based on DoE design, this method for measuring ADCP potency of anti-CD38 mAb was optimized and validated with good specificity, repeatability and accuracy. This method can be used for evaluation of ADCP biological activity of anti-CD38 mAbs.
ABSTRACT
The high performance liquid chromatography-fluorescence micelle assay (HPLC-FMA) method for the content determination of polysorbate 80 in monoclonal antibody drugs was validated to study its applicability and transferability between various laboratories, and the feasibility to be included in the Chinese Pharmacopoeia. Both J.T. Baker and Nanjing Well-sourced polysorbate 80 was used in the collaborative validation of polysorbate 80 content analysis in seven different laboratories. The results show that when the protein concentration was no more than 20 mg·mL-1 and the concentration of polysorbate 80 ranged from 0.05 to 0.5 mg·mL-1, the method had good specificity. The recovery rates of the spiked samples ranged from 92.20% to 117.70% for J.T.Baker and from 93.90% to 117.20% for Nanjing Well. The intra-laboratory precision (%RSD) was less than 4.30% for J.T. Baker, and less than 2.60% for Nanjing Well, while the overall precision was less than 5.45% for J.T. Baker, and less than 6.70% for Nanjing Well. The linear correlation coefficient was more than 0.98 for J.T. Baker and more than 0.99 for Nanjing Well. The results of the collaborative validation prove that the HPLC-FMA method has good accuracy, precision, linearity, and specificity, and could be used for release control analysis of polysorbate 80 content in monoclonal antibodies across different laboratories.
ABSTRACT
The bioactivity of a working reference standard was determined by replicate bioassays with calibration against a primary reference standard. In this study the number of bioassay replicates needed for calibration first was calculated theoretically, and if the mean value of the experimental bioassay replicates fell within the predefined bioactivity level the bioactivity of the working reference was defined as 100%. Our results showed that when the total intermediate precision of the bioassay method was at 11.66% and the predefined bioactivity level was set at 95%-105% with a confidence level of 95%, 21 bioassay replicates should be carried out for calibration. The average value of the 22 experimental bioassay replicates was 101.96%, so the bioactivity of the working reference standard was consistent with that of the primary reference standard at 100%. The results suggest that a strategy of first calculating the number of bioassay replicates needed for calibration and then determining whether the resulting experimental mean value is within the predefined bioactivity level will be of value to the biopharmaceutical industry.
ABSTRACT
A collaborative inter-laboratory validation was carried out using a reporter gene assay to measure the bioactivity of anti-PD-1 monoclonal antibody, in order to study the applicability and transferability of the method. In this study, two collaborative schemes were designed to measure the precision, linearity and accuracy of the method. The results showed that the 95% confidence interval (CI) of the intra-assay precision was (1.72-16.89) %, inter-assay precision was (2.63-17.67) %, inter-laboratory precision was (9.00-14.26) %, all linear correlation coefficients were greater than 0.99, and the 95% CI for the accuracy at different potency levels was (91.83-104.40) % at 50%, (90.40-101.40) % at 75%, (94.71-105.60) % at 100%, (94.00-102.00) % at 125%, and (96.73-104.30) % at 150%. The collaborative validation results proved that the reporter gene assay for the bioactivity determination of anti-PD-1 monoclonal antibody has good precision, linearity and accuracy, and could be applied to the release and stability analysis of anti-PD-1 monoclonal antibodies in different laboratories.
ABSTRACT
Monoclonal antibodies (mAbs) have been widely used as therapeutic drugs for treating diseases such as cancers and auto-immune diseases. When using an IgG4 isotype, one of the challenges is the instability of its hinge which is prone to Fab-arm exchange (FAE). The hinge sequence of a wild type IgG4 is -CPSC-, however, a single point mutation S228P from -CPSC- to -CPPC- can effectively diminish FAE, thereby improving hinge stability of the IgG4 molecule. Sintilimab is the fully human anti-PD-1 monoclonal antibody designed and developed for immuno-oncology, in which serine 228 in the hinge was engineered to proline to mitigate FAE. In this study, LC-MS is used to study hinge stability of sintilimab in both in vitro (PBS and human serum) and in vivo (SCID mouse) studies. The studies demonstrate that LC-MS is a fast and simple way to monitor for the occurrence of FAE in vitro and in vivo, and FAE can be eliminated by antibody engineering with a single point mutation.
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A non-reduced SDS-PAGE purity method for quantitation of conbercept fragments was established based on gel screening, comparison of gel imaging system, linearity range of main band, screening of destaining conditions. The results indicated that the bands could be separated effectively with good clearness and flatness on 4%-15% gradient concentration gel, the peaks of all bands could be separated from baseline using high-distinguishability gel imaging system, the signal intensity of a main band had shown a good linearity with ≤ 3 μg of loading amount, and that the destaining was set as a total of ≤ 3 h with exchanging 100 mL destaining buffer every 60 min. The established non-reduced SDS-PAGE method could demonstrate the purity of conbercept more objectively. After validation, the established non-reduced SDS-PAGE method was submitted to FDA in the form of supplementary materials, which laid a quality basis for the direct entry of conbercept to the clinical Ⅲ study in the United States.
ABSTRACT
The biological activity of ADCC by anti-CD20 monoclonal antibody was determined by BioGlo™ Luciferase Assay System using Jurkat/NFAT-luc+FcγRIIIa cell line as effector cell and WIL2-S cell line as target cell. The developed method was verified for specificity, precision and accuracy. Anti-CD20 monoclonal antibody showed a dose-response mode by the developed method, and the determination result complied with the following four-parameter equation: y = (A-D)/[1 + (X/C)(B)] + D. The optimized parameters of the method were determined including the antibodies diluted concentration (18,000 ng·mL(-1)), dilution rate (1:5), the ratio of effector cell and target cell (6:1), and induction time (6 h). The values of eight independent tests have passed a statistical test for curve regression analysis, linear or parallelism, which showed the method possessed good specificity. Four different dilute groups of recovery rates sample were determined for 3 times, and the result showed mean relative potencies of (44.39±3.93)%, (72.74±2.78)%, (128.28±7.01)% and (168.19±2.70)% respectively, with a variation coefficient of less than 10%, and the recoveries of (88.78±7.85)%, (96.99±3.70)%, (102.63±5.61)% and (112.12±1.80)% respectively. A novel reporter gene method for determination of biological activity of ADCC by anti-CD20 monoclonal antibody was successfully developed, which showed strong specificity, good reproducibility and high accuracy, and might be used routinely.
Subject(s)
Humans , Antibodies, Monoclonal, Murine-Derived , Pharmacology , Antibody-Dependent Cell Cytotoxicity , Antigens, CD20 , Allergy and Immunology , Genes, Reporter , Reproducibility of Results , RituximabABSTRACT
This paper reports the determination of the drug antibody ratio in an antibody-drug conjugate with two methods, i.e. LC-MS and UV/VIS, and to provide a reliable method to scientifically evaluate and effectively control the drug antibody ratio. Deglycosylated sample was analyzed with C4 column followed by MS, and the number of conjugated drugs in the antibody was determined by the molecular weight increase due to the addition of different number of drugs to the antibody, and then drug antibody ratio was calculated by weighted average of different number of drugs conjugated to the antibody. Optical density at 252 and 280 nm was measured with UV/VIS, and due to the difference of extinction coefficients between the antibody and the drug, the drug antibody ratio was calculated from linear equation with two unknowns. The drug antibody ratio was 3.21 and 3.25 respectively measured by the two methods, and the results were similar with the two methods. Our study indicated that both methods, LC-MS and UV/VIS, could be applied to the analysis of drug antibody ratio of the antibody drug conjugate.