Macrocyclic HCV Inhibitors for Sustained Efficacy
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Solution Overview
Problem
Current hepatitis C virus (HCV) therapies face challenges such as limited efficacy, significant side effects, emergence of drug-resistant mutants, and compliance issues due to sub-optimal pharmacokinetics and complex dosage regimes, necessitating the development of more effective and tolerable treatments.
Innovation Solution
Development of pharmacologically acceptable macrocyclic HCV replication inhibitors with low molecular weight, ease of synthesis, and availability of starting materials, represented by formula (I), which can inhibit HCV replication effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If current HCV therapies (interferon-alpha in combination with ribavirin) are used, then sustained virologic response is achieved in more than 40% of patients infected by genotype 1 viruses, but significant side effects occur including influenza-like symptoms, hematologic abnormalities, and neuropsychiatric symptoms
Solution Approach 1:
The patent changes the chemical structure parameters from peptidomimetic inhibitors to macrocyclic compounds with specific molecular weight ranges (500-1500 Da), aiming to improve pharmacokinetic properties and reduce side effects while maintaining antiviral efficacy. The macrocyclic structure with specific ring sizes and substituent patterns represents a parameter change in the drug molecule's physical and chemical properties.
Solution Approach 2:
The invention employs composite molecular structures combining macrocyclic cores with various functional groups and substituents (R1a, R1b, R2, R3, R4, R5a, R5b groups) to create compounds with optimized pharmacological properties. This composite approach allows tuning of solubility, stability, and target binding while reducing adverse effects associated with simpler structures.
2Reliability
If peptidomimetic HCV protease inhibitors (BILN-2061 or VX-950) are administered, then HCV replication is inhibited, but HCV mutants with drug resistance emerge characterized by mutations in the HCV protease genome
Solution Approach 1:
The patent changes the inhibitor structure from linear peptidomimetics to cyclic macrostructures, fundamentally altering the binding mode and interaction profile with the HCV protease active site. This structural parameter change aims to achieve more stable inhibition that is less susceptible to protease mutations, thereby reducing drug resistance development.
Solution Approach 2:
The macrocyclic structure introduces curvature and three-dimensional rigidity compared to flexible linear peptidomimetics. This spheroidal/cyclic architecture creates a more defined binding geometry that may engage multiple subsites in the protease active site simultaneously, reducing the impact of single-point mutations and delaying resistance emergence.
3Reliability
If sub-optimal pharmacokinetics and complex dosage regimes are used, then HCV treatment is initiated, but compliance failures occur and 24 hour trough concentration falls below the IC 90 or ED 90 threshold
Solution Approach 1:
The patent optimizes pharmacokinetic parameters by designing macrocyclic compounds with specific molecular weights (500-1500 Da), lipophilicity, and metabolic stability. These parameter changes aim to achieve sustained plasma concentrations above IC90/ED90 thresholds with once-daily or less frequent dosing, simplifying the dosage regime and improving patient compliance.
Solution Approach 2:
The invention employs macrocyclic structures with extended half-lives that maintain therapeutic concentrations for prolonged periods, effectively using partial dosing (less frequent administration) to achieve sustained efficacy. This approach ensures trough levels remain above the IC90 threshold throughout the dosing interval, eliminating the need for complex multiple-daily dosing schedules.
4Ease of manufacture
If macrocyclic HCV replication inhibitors with low molecular weight are developed, then ease of synthesis and availability of starting materials are improved, but maintaining effective trough levels and reducing resistant mutants requires optimization of pharmacokinetic properties
Solution Approach 1:
The patent segments the macrocyclic molecule into modular components (core macrocycle with variable R1a, R1b, R2, R3, R4, R5a, R5b substituents) that can be synthesized separately and assembled. This segmentation enables use of commercially available starting materials and standard organic synthesis techniques, simplifying manufacturing while allowing optimization of pharmacokinetic properties through systematic variation of substituent groups.
Data Source
AI summary
Inhibitors of HCV replication of formula (I), and the N-oxides, salts, and stereoisomers thereof, wherein each dashed line represents an optional double bond; X is ?, CH and where X bears a double bond it is C; R1a and R1b are hydrogen, C3-7cycloalkyl, aryl, Het, C1-6alkoxy, C1-6alkyl optionally substituted with halo, C1-6alkoxy, cyano, polyhaloC11-6alkoxy, C3-7cycloalkyl, aryl, or with Het; or R1a and R1b together with the nitrogen to which they are attached form a 4 to 6 membered heterocyclic ring which may be optionally substituted; L is a direct bond, -O- , -O-C1-4alkanediyl-, -O-CO-, -O-C(=O)-?R5a - or -O -C(=O)-NR5a-C1-4alkanediyl-; R2 is hydrogen, and where X is C or CH, R2 may also be C1-6alkyl; R3 is hydrogen, C1-6alkyl, C1-6alkoxyC1-6alkyl, C3-7cycloalkyl, amino, mono- or diC1-6alkylamino; R4 is aryl or a saturated, a partially unsaturated or completely unsaturated 5 or 6 membered monocyclic or 9 to 12 membered bicyclic heterocyclic ring system wherein said ring system contains one nitrogen, and optionally one to three additional heteroatoms selected from O, S and N, and wherein the remaining ring members are carbon atoms; wherein said ring system may be optionally substituted; n is 3, 4, 5, or 6; p is 1 or 2; aryl is phenyl, naphthyl, indanyl, or 1,2,3,4-tetrahydronaphthyl, each of which may be optionally substituted with one, two or three substituents; and Het is a 5 or 6 membered saturated, partially unsaturated or completely unsaturated heterocyclic ring containing 1 to 4 heteroatoms selected from N, O and S , being optionally condensed with a benzene ring, and wherein Het may be optionally substituted with one, two or three substituents; pharmaceutical compositions containing compounds (I) and processes for preparing compounds (I).