PEGylation Of Recombinat Human Interleukin-11 Mutein And Its Pharmacokinetics And Pharmacodynamics In Preclinical Trial

Thrombocytopenia is the critical factor restricting the dose of anti-tumor drugs being used to cancer patients,and recombinant human interleukin 11?rhIL-11?is the mainapproveddrugforthetreatmentofchemotherapy-induced thrombocytopenia?CIT?,however,the use of rhIL-11 has been associated with frequent administration and unacceptably side effects,restricting its use.In order to solve these two problems,a novel recombinant human interleukin-11 mutein?mIL-11?was chosen as a model drug for the study of PEGylation,and Lys³³-site specific PEGylation of m IL-11 was obtained for the first time,which was named as PEG-m IL-11.In this study we examined the feasibility of single site specific modification of m IL-11 by polyethylene glycol?PEG?,and then the modification site was analysed,the quality standard was established,the preliminary stability of PEG-m IL-11 was studied,the preclinical pharmacokinetics and pharmacodynamics were investigated in two animals.The 20kDa PEG was used to modify m IL-11,five major effects in the reaction were investigated.The optimized reaction condition for the highest yield of monoPEGylated mIL-11 was as follows:pH 8.2,concentration of m IL-11 0.8mg/ml,molar ratio of mPEG-SC/m IL-11 5.5,and reaction time 1h at temperature 2-8?.Under the optimized reaction condition,a high mono-modification rate of 53%was achieved in a larger scale,furthermore,the modification process is stable and reproducible by three batches process validation.To confirm that PEG-mIL-11 was PEGylated at Lys33 position,N-terminus sequencing and peptide mapping analysis were performed.At the same time,bioactivity of the PEGylated mIL-11 was as active as that of m IL-11 revealed by in vitro biological activity assay.In addition,the quality standard was established,and the drug stability was confirmed by repeated freezing and thawing,acceleration stability and long-term observation tests for six months.These results indicated that PEG-m IL-11 has good stability.A specific detection method of PEG-m IL-11 in monkey plasma was established and validated,the pharmacokinetics feature was evaluated through normal and myelosuppression cynomolgus monkey models,and the results showed that the pharmacokinetics features of PEG-m IL-11 was significantly improved after PEGylation,and with a dose-dependent enhancement at 150-600?g/kg dose range.The pharmacodynamics effects of PEG-mIL-11 was studied by thrombocytopenia mice and monkey models,which showed that 1-2 doses administration of PEG-mIL-11 induced blood platelets number increase and the effect duration were comparable to that of 7 to 10 consecutive daily administration of native m IL-11.In comparison with m IL-11,PEG-mIL-11 possessed improved pharmacokinetics feature and lower dose frequency,indicating a better compliance of the treatment rigimen,has the potential and the clinical application value as therapeutic biological class 1 drug.