State of the Art, Unresolved Issues, and Future Research Directions in the Fight against Hepatitis C Virus: Perspectives for Screening, Diagnostics of Resistances, and Immunization

Table 1

Direct-acting antivirals (DDAs) approved for HCV treatment or investigated in clinical trials (updated in September 2016).

Class	Generation	Approved substances (developing company)	Substances currently tested in clinical trials (developing company) [phase of development]
NS3/4A protease inhibitors	First generation	Telaprevir (Janssen, Mitsubishi); Boceprevir (Merck); Simeprevir (Janssen); Paritaprevir (AbbVie); Asunaprevir (Bristol-Myers Squibb); Vaniprevir (Merck)
	Second generation	Grazoprevir (Merck)	ABT-493 (AbbVie) [Phase 3]; GS-9857 (Gilead Sciences) [Phase 3]
NS5A inhibitors	First generation	Daclatasvir (Bristol-Myers Squibb); Ledipasvir (Gilead Sciences); Ombitasvir (AbbVie); Elbasvir (Merck); Velpatasvir (Gilead Sciences)	Odalasvir (Janssen) [Phase 2]; Ravidasvir (Presidio) [Phase 2/3]
	Second generation		ABT-530 (AbbVie) [Phase 3]; MK-8408 (Merck) [Phase 2]
Nucleotide analogue inhibitors of NS5B RNA-dependent RNA polymerase	First generation	Sofosbuvir (Gilead Sciences)	MK-3682 (Merck) [Phase 2]; AL-335 (Janssen) [Phase 2]
Nonnucleoside inhibitors of NS5B RNA-dependent RNA polymerase	Palm-1 inhibitors	Dasabuvir (AbbVie)