RESUMO
Aim: RBD1016 is an N-acetylgalactosamine-conjugated siRNA drug currently in a phase II trial for treatment of chronic hepatitis B virus. To evaluate its absorption, distribution, metabolism and excretion (ADME) and pharmacokinetic/pharmacodynamic (PK/PD) properties, two LC-based bioanalytical methods, LC-high-resolution/accuracy MS and LC-fluorescence detection, were developed and qualified. Materials & methods: The LC-high-resolution/accuracy MS method was used for metabolite identification and simultaneous quantitation of the antisense and sense strands as well as their respective metabolites. The LC-fluorescence detection assay was primarily used for analyzing the antisense strand and its metabolites in low-concentration plasma samples. The two methods were successfully bridged by analyzing the same sets of study samples. Results & conclusion: Both methods were found to have excellent accuracy/precision, specificity and reproducibility to support ADME and PK/PD studies of RBD1016 siRNA.
Assuntos
Hepatite B Crônica , Humanos , Cromatografia Líquida/métodos , RNA Interferente Pequeno , Reprodutibilidade dos Testes , Hibridização de Ácido NucleicoRESUMO
Small interfering RNA (siRNA) constitutes a promising therapeutic modality supporting the potential functional cure of hepatitis B. A novel ionizable lipidoid nanoparticle (RBP131) and a state-of-the-art lyophilization technology were developed in this study, enabling to deliver siRNA targeting apolipoprotein B (APOB) into the hepatocytes with an ED50 of 0.05 mg/kg after intravenous injection. In addition, according to the requirements of Investigational New Drug (IND) application, a potent siRNA targeting hepatitis B virus (HBV) was selected and encapsulated with RBP131 to fabricate a therapeutic formulation termed RB-HBV008. Efficacy investigations in transient and transgenic mouse models revealed that the expressions of viral RNAs and antigens (HBsAg and HBeAg), as well as viral DNA, were repressed, dose-dependently and time-dependently at multilog decreasing amplitude, in both circulation and liver tissue. In contrast, entecavir (ETV), the first-line clinically-employed nucleoside analog drug, barely recused the antigen expression, although it triggered as high as 3.50 log reduction of viral DNA, in line with clinical observations. Moreover, the toxicity profiles suggested satisfactory safety outcomes with ten times the therapeutic window. Therefore, this study provides an effective nucleic acid delivery system and a promising RNAi agent for the treatment of hepatitis B.
Assuntos
Regulação Viral da Expressão Gênica/efeitos dos fármacos , Antígenos de Superfície da Hepatite B , Antígenos E da Hepatite B , Vírus da Hepatite B , Hepatite B , RNA Interferente Pequeno , Células Hep G2 , Hepatite B/tratamento farmacológico , Hepatite B/genética , Hepatite B/metabolismo , Antígenos de Superfície da Hepatite B/biossíntese , Antígenos de Superfície da Hepatite B/genética , Antígenos E da Hepatite B/biossíntese , Antígenos E da Hepatite B/genética , Vírus da Hepatite B/genética , Vírus da Hepatite B/metabolismo , Humanos , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/farmacologiaRESUMO
A new oil suspension containing 0.15% ivermectin and 15% praziquantel for intramuscular injection was developed, and corresponding pharmacokinetics studies were conducted in swine. The combination product is a white- to cream-colored oil suspension and its physical properties such as settling volume ratio, redispersibility, syringeability and flowability are well consistent with the Technical Standards by the Ministry of Agriculture of the People's Republic of China. The pharmacokinetic study consists of two parts. First, the experiments were carried out to compare the pharmacokinetic parameters of the combination product and those same products with praziquantel or ivermectin removed merely. The results showed that no significant change in the major pharmacokinetic parameters (t(1/2z), T(max), C(max), AUC(INF), TimeDur) was observed when either of the component was removed from the combination product, indicating that ivermectin and praziquantel do not interfere with each other when being used together. Second, the pharmacokinetics of the combination product were compared with those of their respective single product. The results showed that the C(max) (15.94 ng/mL) of ivermectin in combination product was 9.01 times higher than the single product, while the AUC(INF) (1925.61 ng h/mL) was 6.02 times higher. Meanwhile, the C(max) (1.48 µg/mL), AUC(INF) (17.08µgh/mL), t(1/2z) (20.25 h), TimeDur3 (42.01 h) and TimeDur4 (16.60 h) of praziquantel in combination product were improved with a factor of 5.48, 13.66, 8.58, 10.10 and 7.31 times when compared with the single product, respectively. Therefore, the efficacy of the combination product was significantly prolonged, especially for praziquantel, so that comprehensive efficacy of controlling parasites sensitive to ivermectin and praziquantel can be achieved with one-single use of it.
