Elbasvir (Single Agent) + Grazoprevir (Single Agent) = Unknown or no reaction

Study Design

In an open-label, multiple-dose study, 10 healthy adult subjects received grazoprevir (GZR, MK-5172) 200mg* once daily for 7 days. Following a 7-day washout, subjects received Elabasvir (EBR, MK-8742) 20mg once daily for 7 days, followed by coadministration of GZR 200mg daily plus EBR 20mg once daily for 8 days.* Since GZR exposure is approximately 2-fold higher in HCV-infected patients compared to healthy subjects, a 200mg dose was given instead of the intended 100mg dose to be used in HCV-infected patients.

Study Results

Coadministration of GZR and EBR did not result in clinically significant changes in pharmacokinetic parameters of either drug. Geometric mean ratios (GMRs; GZR+EBR/EBR) [90% CIs] of AUC, Cmax, and C24h for EBR were 1.01 [0.83, 1.24], 0.93 [0.76, 1.13], and 1.02 [0.83, 1.24], respectively. GMRs (GZR+EBR/GZR) [90% CIs] of AUC, Cmax, and C24h for GZR were 0.90 [0.63, 1.28], 0.87 [0.50, 1.52], and 0.94 [0.77, 1.15], respectively.In vivo and in vitro data suggest that the effect of the 50mg dose of EBR is expected to be comparable to 20mg doses. The authors state that no dose adjustment will be necessary when GZR and EBR are co-administered in HCV patients.

Study Conclusions

References

W Yeh, L Caro, X Huang, et al. No pharmacokinetic interaction between hcv protease inhibitor mk-5172 and hcv ns5a inhibitor mk-8742 in healthy volunteers [abstract 478]. 64th Annual Meeting Of The American Association For Thestudy Of Liver Diseases (aasld). Washington, DC. ; 2013.