Pharmacokinetic Study Of Antisense Oligodeoxynucleotides Cantide In Rhesus Monkeys

Cantide is a 20-mer full phosphorothioate antisense oligodeoxynucleotide and belongs to the first generation antisense nucleotide. It inhibits express of telomerase catalytic subunit hTERT through base complementrity, so the growth of tumor could be repressed by restraining telomerase activation.The present study evaluates the pharmacokinetic properties of Cantide in rhesus monkeys, as parts of the non-clinical pharmacological study of Cantide.To characterize the preclinical pharmacokinetics, plasma concentration-time of Cantide and pharmacokinetic behavior after vd administration at three different doses(8,16,24 mg·kg^-1)and multiple dose of 8 mg·kg^-1 for 7 days in rhesus monkeys have been studied and compared. At the same time, the pharmacokinetic properties of metabolites(n-1 and n-2) have been evaluated and compared.1. The optimizations and method validation of analytical methods for quantitative determination of Cantide in rhesus monkeys plasmaA dual solid phase extraction (SPE) pretreatment coupling with non-gel sieving capillary electrophoresis (NGCE) analysis method was established for quantitative determination of oligodeoxynucleotide, Cantide, in rhesus monkeys plasma. The SPE conditions and the NGCE analysis conditions were optimized, under this optimization conditions(The SPE conditions: the pH of loading buffer was 9.0, the loading volume and elution volume of anion-exchange column was 5 mL and 3 mL,respectively; the NGCE analysis conditions:the loading gel time was 30 min and separation voltage was 24 kV), the linear dynamic range of Cantide in rhesus monkeys plasma was 1.95²50μg·mL^-1, and correlation coefficients (R) was > 0.998. The lower limit of quantitation (LLOQ) was 1.95μg·mL^-1.The intra-day accuracy ranged from 93.38 % to 100.71 % , the intra-day relative standard deviation(intra-day RSD)was <10.66 %. The inter-day accuracy was from 89.46 % to 103.46 %, the inter-day relative standard deviation(inter-day RSD)was < 8.60 %. The stability experiments showed that Cantide plasma samples were stable when stored at 4℃for 24 h, room temperature for 4 h, -80℃for 30 days, 7 months and freeze-thaw for 2 cycles.The validity studies demonstrated that the method was reliable for the determination of plasma Cantide levels and finally applied to pharmacokinetic study of Cantide in rhesus monkeys.2. The plasma concentration-time of Cantide and metabolites and pharmacokinetic parameters after vd administration of 8,16 and 24 mg·kg^-1 in rhesus monkeysAfter vd administration at doses of 8, 16, 24 mg·kg^-1 in rhesus monkeys, the time of plasma concentration reached maximum was 32.50±2.89, 32.50±2.89 and 28.75±6.29 min, respectively. Cmax of the three groups was 72.21±8.68, 110.90±11.22 and 150.01±17.84μg·mL^-1, statistical significant differences has been found among the groups.The terminal half-life were 57.91±23.64, 73.58±25.45 and 77.94±8.84 min, statistical significant differences of the t1/2 has been not found among the groups. AUC(0-t) were 4874.46±844.08, 6998.54±1094.18 and 11057.38±2068.03μg·min·mL^-1, AUC(0-inf) were 5148.73±1018.81, 7392.22±1019.76 and 12462.22±3485.74μg·min·mL^-1, statistical significant differences of AUC has been found among the groups. Dose ratio was 1: 2: 3 and the increase of AUC(0-inf) were 1: 1.43: 2.42. The clearance were 1.60±0.31,2.19±0.27,2.04±0.53 mL·min-1·kg^-1, respectively.Statistical results of pharmacokinetic parameters and the plasma concentration of metabolites(n-1 and n-2) were similar as those of Cantide. The concentration-time curve of metabolites(n-1 and n-2) were lower than those of Cantide, and they reached the Cmax following Cantide immediately. It have been found that metabolites were cleared more quickly Compared with the pharmacokinetic properties of Cantide. But the MRT and T1/2 were longer than that of Cantide.3. The plasma concentration-time of Cantide and metabolites and pharmacokinetic parameters after multiple vd administration of 8 mg·kg^-1 in rhesus monkeysAfter vd administration at doses of 8 mg·kg^-1 in rhesus monkeys, the time of plasma concentration reached maximum was 35.00±7.07 min, Cmax was 58.34±17.39μg·mL^-1. the terminal half-life was 57.45±24.38 min, the clearance was 1.85±0.14 mL·mi^n-1·kg^-1. AUC(0-t) was 4010.71±223.81μg·min·mL^-1, AUC(0-inf) was 4335.55±306.16μg·min·mL^-1, Compared with vd administration at the first time, there was no statistical significant differences among all parameters. There was no statistical significant differences has been found that plasma concentration and pharmacokinetic properties of metabolites in rhesus monkey.