Development of potent macrocyclic inhibitors of genotype 3a HCV NS3/4A protease

P2-quinazolinones and bis-macrocycles as new templates for next-generation hepatitis C virus NS3/4a protease inhibitors: discovery of MK-2748 and MK-6325

With the goal of identifying inhibitors of hepatitis C virus (HCV) NS3/4a protease that are potent against a wide range of genotypes and clinically relevant mutant viruses, several subseries of macrocycles were investigated based on observations made during the discovery of MK-5172. Quinazolinone-containing macrocycles were identified as promising leads, and optimization for superior cross-genotype and mutant enzyme potency as well as rat liver and plasma concentrations following oral dosing, led to the development of MK-2748. Additional investigation of a series of bis-macrocycles containing a fused 18- and 15-membered ring system were also optimized for the same properties, leading to the discovery of MK-6325. Both compounds display the broad genotype and mutant potency necessary for clinical development as next-generation HCV NS3/4a protease inhibitors.

The discovery of asunaprevir (BMS-650032), an orally efficacious NS3 protease inhibitor for the treatment of hepatitis C virus infection

The discovery of asunaprevir (BMS-650032, 24) is described. This tripeptidic acylsulfonamide inhibitor of the NS3/4A enzyme is currently in phase III clinical trials for the treatment of hepatitis C virus infection. The discovery of 24 was enabled by employing an isolated rabbit heart model to screen for the cardiovascular (CV) liabilities (changes to HR and SNRT) that were responsible for the discontinuation of an earlier lead from this chemical series, BMS-605339 (1), from clinical trials. The structure-activity relationships (SARs) developed with respect to CV effects established that small structural changes to the P2* subsite of the molecule had a significant impact on the CV profile of a given compound. The antiviral activity, preclincial PK profile, and toxicology studies in rat and dog supported clinical development of BMS-650032 (24).

HCV NS3/4a Protease Inhibitors: Simeprevir (TMC‐435350), Vaniprevir (MK‐7009) and MK‐5172

Hepatitis C virus (HCV) infection continues to represent a major health issue, with estimates of 130–170 million people infected worldwide. Recent developments in the HCV NS3/4a protease inhibitor area have significantly improved treatment options for patients. However, a more dramatic paradigm shift in the treatment of HCV infection appears all but certain in coming years, with a move to all oral combination therapy with direct‐acting antivirals (DAAs). HCV protease inhibitors have the potential to play a significant role in these DAA combination therapies. This chapter discusses in detail the design and discovery of three HCV NS3/4a protease inhibitors in clinical development: simeprevir (TMC‐435350), vaniprevir (MK‐7009) and MK‐5172.