ABSTRACT
Liquid chromatography tandem mass spectrometry (LC-MS/MS) has gradually become a promising alternative to ligand binding assay for the bioanalysis of biotherapeutic molecules,due to its rapid method development and high accuracy.In this study,we established a new LC-MS/MS method for the determination of the anti-sclerostin monoclonal antibody (SHR-1222) in cynomolgus monkey serum,and compared it to a previous electrochemiluminescence method.The antibody was quantified by detecting the surrogate peptide obtained by trypsin digestion.The surrogate peptide was carefully selected by investigating its uniqueness,stability and MS response.The quantitative range of the pro-posed method was 2.00-500 μg/mL,and this verified method was successfully applied to the tox-icokinetic assessment of SHR-1222 in cynomolgus monkey serum.It was found that the concentrations of SHR-1222 in cynomolgus monkeys displayed an excellent agreement between the LC-MS/MS and electrochemiluminescence methods (ratios of drug exposure,0.8-1.0).Notably,two monkeys in the 60 mg/kg dose group had abnormal profiles with a low detection value of SHR-1222 in their individual sample.Combining the high-level anti-drug antibodies (ADAs) in these samples and the consistent quantitative results of the two methods,we found that the decreased concentration of SHR-1222 was due to the accelerated clearance mediated by ADAs rather than the interference of ADAs to the detection platform.Taken together,we successfully developed an accurate,efficient and cost-effective LC-MS/MS method for the quantification of SHR-1222 in serum samples,which could serve as a powerful tool to improve the preclinical development of antibody drugs.
ABSTRACT
BACKGROUND:Sclerostin can negatively regulate the bone metabolism, and the sclerostin monoclonal antibody can antagonize the negative regulation effect, inhibit bone resorption and promote bone formation. OBJECTIVE:To explore the mechanism and application progress of sclerostin monoclonal antibody in the treatment of osteoporosis. METHODS:An online search of PubMed database, CNKI database, VIP database and Wanfang database between May 2005 and May 2013 was performed by the first author to search the related articles with the key words of“osteoporosis, antibody, sclerostin, Wnt, SOST”in both English and Chinese. Articles related to sclerostin monoclonal antibody were included. For the articles in the same field, those published earlier or in the authorized journals were preferred. RESULTS AND CONCLUSION:A total of 170 articles were obtained after initial search, and final y 54 articles related to sclerostin monoclonal antibody were included for review according to the inclusion criteria. The sclerostin can block Wnt pathway through combining with low-density lipoprotein receptor-related protein 5/6, thus inhibiting the differentiation and mineralization of osteoblasts. By specifical y binding to sclerostin, the sclerosin monoclonal antibody can indirectly promote bone formation and restrain bone absorption which has great significance in the treatment of osteoporosis. Meanwhile, compared with the other treatment method, the specific targeting of sclerostin and the binding specificity of sclerostin monoclonal antibody provide application advantages for the treatment of osteoporosis.