PCSK9 siRNA Conjugates for LDL-C Lowering With Better Tolerability
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Solution Overview
Problem
Current therapies for hypercholesterolemia, such as statins, antibody treatments, and small molecule inhibitors of PCSK9, have tolerability issues and limitations, and there is a need for additional therapeutic options to manage plasma LDL levels effectively.
Innovation Solution
Development of RNAi agents comprising modified nucleotides and a targeting ligand, specifically designed to inhibit PCSK9 gene expression, which are administered to inhibit PCSK9 gene expression in hepatocytes, thereby reducing PCSK9 protein levels and treating PCSK9-related diseases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If statins, antibody treatments, or small molecule inhibitors of PCSK9 are used to lower LDL-C levels, then cholesterol metabolism is improved, but tolerability issues and treatment limitations occur
Solution Approach 1:
The patent applies parameter changes by modifying the chemical structure of nucleotides within the RNAi agent (e.g., 2'-O-methyl modifications, phosphorothioate backbone modifications) to alter the molecule's properties. These modifications enhance stability, reduce immunogenicity, and improve tolerability while maintaining the agent's ability to inhibit PCSK9 and lower LDL-C levels effectively
Solution Approach 2:
The patent employs composite materials by creating chimeric RNA molecules that combine different nucleotide types (modified and unmodified) within a single RNAi agent structure. This composite approach allows the molecule to maintain RNAi activity while incorporating modified nucleotides that reduce off-target effects and improve tolerability, thus resolving the contradiction between effectiveness and tolerability
2Productivity
If existing PCSK9 inhibitors are administered to treat hypercholesterolemia, then plasma LDL levels are reduced, but additional therapeutic options are needed due to treatment limitations
Solution Approach 1:
The patent applies segmentation by designing RNAi agents with specific 21-nucleotide antisense regions that can be independently optimized to target different regions of the PCSK9 mRNA. This segmentation allows for the development of multiple distinct RNAi agents with potentially different pharmacokinetic and pharmacodynamic profiles, providing versatile therapeutic options while maintaining high LDL-C lowering efficacy
Solution Approach 2:
The patent demonstrates universality by creating a platform technology where modified RNAi agents can target PCSK9 with high efficacy while the same platform could potentially be adapted to target other genes involved in cholesterol metabolism or cardiovascular disease. The modified nucleotide framework provides a universal solution that addresses both efficacy and the need for diverse therapeutic options
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The RNAi agents effectively reduce PCSK9 gene expression, providing therapeutic benefits for hypercholesterolemia and related cardiovascular diseases by lowering LDL-C levels, offering an alternative to existing therapies with fewer tolerability issues.
Implementation Method 1
RNA interference (RNAi) agents, e.g., double stranded RNAi agents, for inhibition proprotein convertase subtilisin kexin 9 (PCSK9) gene expression
Implementation Method 2
a sense strand comprising a nucleotide sequence that is at least partially complementary to the antisense strand
Data Source
AI summary
The present disclosure relates to RNAi agents, e.g., double stranded RNAi agents such as small interfering RNA (siRNA) molecules, able to inhibit proprotein convertase subtilisin kexin 9 (PCSK9) gene expression. Also disclosed are pharmaceutical compositions that include PCSK9 RNAi agents and methods of use thereof. The PCSK9 RNAi agents disclosed herein may be conjugated to targeting ligands, including ligands that comprise N-acetyl-galactosamine, to facilitate the delivery to hepatocyte cells. Delivery of the PCSK9 RNAi agents in vivo provides for in vivo provides for inhibition of PCSK9 gene expression and thereby reduction of PCSK9 protein. The RNAi agents can be used in methods of treatment of diseases or disorders mediated at least in part by PCSK9 gene expression, including among others hypercholesterolemia, familial hypercholesterolemia including heterozygous familial hypercholesterolemia (HeFH) and homozygous familial hypercholesterolemia (HoFH), familial hypobetalipoproteinemia, hyperlipidemia, coronary artery disease, polygenic dyslipidemia, heart disease, cardiovascular disease (CVD) including clinical atherosclerotic cardiovascular disease (ASCVD).