5 research outputs found
Improving Metabolic Stability with Deuterium: The Discovery of BMT-052, a Pan-genotypic HCV NS5B Polymerase Inhibitor
Iterative structure–activity
analyses in a class of highly
functionalized furoÂ[2,3-<i>b</i>]Âpyridines led to the identification
of the second generation pan-genotypic hepatitis C virus NS5B polymerase
primer grip inhibitor BMT-052 (<b>14</b>), a potential clinical
candidate. The key challenge of poor metabolic stability was overcome
by strategic incorporation of deuterium at potential metabolic soft
spots. The preclinical profile and status of BMT-052 (<b>14</b>) is described
Potent Inhibitors of Hepatitis C Virus NS3 Protease: Employment of a Difluoromethyl Group as a Hydrogen-Bond Donor
The
design and synthesis of potent, tripeptidic acylsulfonamide
inhibitors of HCV NS3 protease that contain a difluoromethyl cyclopropyl
amino acid at P1 are described. A cocrystal structure of <b>18</b> with a NS3/4A protease complex suggests the presence of a H-bond
between the polarized C–H of the CHF<sub>2</sub> moiety and
the backbone carbonyl of Leu135 of the enzyme. Structure–activity
relationship studies indicate that this H-bond enhances enzyme inhibitory
potency by 13- and 17-fold compared to the CH<sub>3</sub> and CF<sub>3</sub> analogues, respectively, providing insight into the deployment
of this unique amino acid
Discovery of a Hepatitis C Virus NS5B Replicase Palm Site Allosteric Inhibitor (BMS-929075) Advanced to Phase 1 Clinical Studies
The hepatitis C virus (HCV) NS5B
replicase is a prime target for
the development of direct-acting antiviral drugs for the treatment
of chronic HCV infection. Inspired by the overlay of bound structures
of three structurally distinct NS5B palm site allosteric inhibitors,
the high-throughput screening hit anthranilic acid <b>4</b>,
the known benzofuran analogue <b>5</b>, and the benzothiadiazine
derivative <b>6</b>, an optimization process utilizing the simple
benzofuran template <b>7</b> as a starting point for a fragment
growing approach was pursued. A delicate balance of molecular properties
achieved via disciplined lipophilicity changes was essential to achieve
both high affinity binding and a stringent targeted absorption, distribution,
metabolism, and excretion profile. These efforts led to the discovery
of BMS-929075 (<b>37</b>), which maintained ligand efficiency
relative to early leads, demonstrated efficacy in a triple combination
regimen in HCV replicon cells, and exhibited consistently high oral
bioavailability and pharmacokinetic parameters across preclinical
animal species. The human PK properties from the Phase I clinical
studies of <b>37</b> were better than anticipated and suggest
promising potential for QD administration
Discovery and Preclinical Characterization of the Cyclopropylindolobenzazepine BMS-791325, A Potent Allosteric Inhibitor of the Hepatitis C Virus NS5B Polymerase
Described herein are structure–activity
relationship studies
that resulted in the optimization of the activity of members of a
class of cyclopropyl-fused indolobenzazepine HCV NS5B polymerase inhibitors.
Subsequent iterations of analogue design and syntheses successfully
addressed off-target activities, most notably human pregnane X receptor
(hPXR) transactivation, and led to significant improvements in the
physicochemical properties of lead compounds. Those analogues exhibiting
improved solubility and membrane permeability were shown to have notably
enhanced pharmacokinetic profiles. Additionally, a series of alkyl
bridged piperazine carboxamides was identified as being of particular
interest, and from which the compound BMS-791325 (<b>2</b>)
was found to have distinguishing antiviral, safety, and pharmacokinetic
properties that resulted in its selection for clinical evaluation
Discovery of a Potent Acyclic, Tripeptidic, Acyl Sulfonamide Inhibitor of Hepatitis C Virus NS3 Protease as a Back-up to Asunaprevir with the Potential for Once-Daily Dosing
The
discovery of a back-up to the hepatitis C virus NS3 protease inhibitor
asunaprevir (<b>2</b>) is described. The objective of this work
was the identification of a drug with antiviral properties and toxicology
parameters similar to <b>2</b>, but with a preclinical pharmacokinetic
(PK) profile that was predictive of once-daily dosing. Critical to
this discovery process was the employment of an ex vivo cardiovascular
(CV) model which served to identify compounds that, like <b>2</b>, were free of the CV liabilities that resulted in the discontinuation
of BMS-605339 (<b>1</b>) from clinical trials. Structure–activity
relationships (SARs) at each of the structural subsites in <b>2</b> were explored with substantial improvement in PK through modifications
at the P1 site, while potency gains were found with small, but rationally
designed structural changes to P4. Additional modifications at P3
were required to optimize the CV profile, and these combined SARs
led to the discovery of BMS-890068 (<b>29</b>)