Reply to Padmanabhan and Dixit: Hepatitis C virus entry inhibitors for optimally boosting direct-acting antiviral-based treatments

We thank Padmanabhan and Dixit for their comments (1) on our paper (2). They pointed out that entry inhibitors might form potent partners for optimal drug combinations. They analyzed previously published data on 10 hepatitis C virus (HCV) entry inhibitors that are under clinical or preclinical development and found some of these HCV entry inhibitors showed high instantaneous inhibitory potentials ( IIP s) (3) compared with IIP s of direct-acting antivirals (DAAs). To analyze further the utility of combining entry inhibitors with other DAAs and to extend our original results (2), we quantified the anti-HCV effect of four different classes of entry inhibitors [AR4A (anti-HCV E2 antibody) (4), BLT-1 \[scavenger receptor class B type 1 (SR-BI) inhibitor\] (5), erlotinib (EGF receptor inhibitor) (6), and dasatinib (EphA2 inhibitor) (6)] singly and in combination with six DAAs studied by Padmanabhan and Dixit (1) in the HCV infectious cell culture system (Fig. 1 A and B ). Single treatment of these entry inhibitors exhibited a dose-dependent reduction in HCV RNA … [↵][1]2To whom correspondence may be addressed. Email: siwami{at}kyushu-u.org or kwatashi{at}nih.go.jp. [1]: #xref-corresp-1-1