Gene Editing as the Future of Cardiac Amyloidosis Therapeutics

Cardiac Amyloidosis (CA) is a manifestation of a systemic disorder resulting from the deposition of transthyretin (TTR) in the myocardium. This leads to a myriad of manifestations ranging from conduction defects to heart failure. Previously CA was considered a rare disease, but recent advances in diagnostics and therapeutics have revealed the prevalence to be higher than estimated. There are two major classes of treatments for TTR cardiac amyloidosis (ATTR-CA): TTR stabilizers, such as tafamidis and AG10, and RNA interference (siRNA), such as patisiran and vutrisiran. Clustered regularly interspaced short palindromic repeats of genetic information-Cas9 endonuclease (CRISPR-Cas9) utilizes an RNA-guided endonuclease to target specific locations in the genome. Until recently, CRISPR-Cas9 was studied in small animal models for its ability to decrease extracellular deposition and accumulation of amyloid in tissues. Gene editing has demonstrated some early clinical promise as an emerging therapeutic modality in the treatment of CA. In an introductory human trial involving 12 subjects with TTR amyloidosis and amyloid cardiomyopathy (ATTR-CM), CRISPR-Cas9 therapy has demonstrated a reduction in approximately 90% of serum TTR proteins after 28 days. In this article, the authors review the current literature on therapeutic gene editing as a prospective curative treatment modality for CA.