1
|
Saffie-Siebert S, Alam I, Sutera FM, Dehsorkhi A, Torabi-Pour N, Baran-Rachwalska P, Iamartino L, Teti A, Maurizi A, Gerard-O'Riley RL, Acton D, Econs MJ. Effect of Allele-Specific Clcn7 G213R siRNA Delivered Via a Novel Nanocarrier on Bone Phenotypes in ADO2 Mice on 129S Background. Calcif Tissue Int 2024; 115:85-96. [PMID: 38733412 DOI: 10.1007/s00223-024-01222-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 04/18/2024] [Indexed: 05/13/2024]
Abstract
Autosomal dominant osteopetrosis type 2 (ADO2) is a rare inherited bone disorder characterised by dense but brittle bones. It displays striking phenotypic variability, with the most severe symptoms, including blindness and bone marrow failure. Disease management largely relies on symptomatic treatment since there is no safe and effective treatment. Most ADO2 cases are caused by heterozygous loss-of-function mutations in the CLCN7 gene, which encodes an essential Cl-/H+ antiporter for proper bone resorption by osteoclasts. Thus, siRNA-mediated silencing of the mutant allele is a promising therapeutic approach, but targeting bone for first-in-human translation remains challenging. Here, we demonstrate the utility of silicon-stabilised hybrid lipid nanoparticles (sshLNPs) as a next-generation nucleic acid nanocarrier capable of delivering allele-specific siRNA to bone. Using a Clcn7G213R knock-in mouse model recapitulating one of the most common human ADO2 mutations and based on the 129S genetic background (which produces the most severe disease phenotype amongst current models), we show substantial knockdown of the mutant allele in femur when siRNA targeting the pathogenic variant is delivered by sshLNPs. We observed lower areal bone mineral density in femur and reduced trabecular thickness in femur and tibia, when siRNA-loaded sshLNPs were administered subcutaneously (representing the most relevant administration route for clinical adoption and patient adherence). Importantly, sshLNPs have improved stability over conventional LNPs and enable 'post hoc loading' for point-of-care formulation. The treatment was well tolerated, suggesting that sshLNP-enabled gene therapy might allow successful clinical translation of essential new treatments for ADO2 and potentially other rare genetic bone diseases.
Collapse
Affiliation(s)
| | - Imranul Alam
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
| | | | | | | | | | | | - Anna Teti
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, 67100, L'Aquila, Italy
| | - Antonio Maurizi
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, 67100, L'Aquila, Italy
| | - Rita L Gerard-O'Riley
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Dena Acton
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Michael J Econs
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| |
Collapse
|
2
|
Karam C, Mauermann ML, Gonzalez-Duarte A, Kaku MC, Ajroud-Driss S, Brannagan TH, Polydefkis M. Diagnosis and treatment of hereditary transthyretin amyloidosis with polyneuropathy in the United States: Recommendations from a panel of experts. Muscle Nerve 2024; 69:273-287. [PMID: 38174864 DOI: 10.1002/mus.28026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 12/04/2023] [Accepted: 12/09/2023] [Indexed: 01/05/2024]
Abstract
Hereditary transthyretin (ATTRv; v for variant) amyloidosis is a rare, multisystem, progressive, and fatal disease in which polyneuropathy is a cardinal manifestation. Due to a lack of United States (US)-specific guidance on ATTRv amyloidosis with polyneuropathy, a panel of US-based expert clinicians convened to address identification, monitoring, and treatment of this disease. ATTRv amyloidosis with polyneuropathy should be suspected in unexplained progressive neuropathy, especially if associated with systemic symptoms or family history. The diagnosis is confirmed through genetic testing, biopsy, or cardiac technetium-based scintigraphy. Treatment should be initiated as soon as possible after diagnosis, with gene-silencing therapeutics recommended as a first-line option. Consensus is lacking on what represents "disease progression" during treatment; however, the aggressive natural history of this disease should be considered when evaluating the effectiveness of any therapy.
Collapse
Affiliation(s)
- Chafic Karam
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | - Alejandra Gonzalez-Duarte
- Department of Neurology, Dysautonomia Center, New York University School of Medicine, New York, New York, USA
| | - Michelle C Kaku
- Department of Neurology, Boston University School of Medicine, Boston Medical Center, Boston, Massachusetts, USA
| | - Senda Ajroud-Driss
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Thomas H Brannagan
- Department of Neurology, Columbia University, Vagelos College of Physicians and Surgeons, New York, New York, USA
| | - Michael Polydefkis
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| |
Collapse
|
3
|
Frizziero L, Salvalaggio A, Cosmo E, Cipriani A, Midena E, Briani C. Ophthalmological involvement in wild-type transthyretin amyloidosis: A multimodal imaging study. J Peripher Nerv Syst 2023; 28:586-596. [PMID: 37552555 DOI: 10.1111/jns.12589] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 08/02/2023] [Accepted: 08/06/2023] [Indexed: 08/10/2023]
Abstract
BACKGROUND AND AIMS Ophthalmological abnormalities have been reported in hereditary transthyretin-related amyloidosis (ATTRv, v for variant) but not in wild-type transthyretin-related amyloidosis (ATTRwt). METHODS Patients with ATTRwt, ATTRv, and light chain amyloidosis (AL) and healthy subjects (controls) underwent complete eye examination, including optical coherence tomography (OCT), OCT angiography (OCTA), and in vivo corneal confocal microscopy (CCM). RESULTS Seventeen ATTRwt, nine ATTRv, two ATTRv carriers, and seven AL patients were enrolled. Compared with other groups, ATTRwt patients had 10 letters lower visual acuity and a higher prevalence of glaucoma, cataract, and retinal pigment epithelium alterations. In the whole group of patients, especially in ATTRwt, we observed (1) a reduced corneal nerve fiber length and more tortuous stromal nerves at CCM, (2) a reduced macular volume and peripapillary nerve fiber layer thickness at OCT, and (3) impairment of peripapillary and macular vascularization at OCTA. INTERPRETATION Ophthalmological abnormalities are common in ATTRwt, significantly impairing visual acuity. Noninvasive imaging modalities allow for the identification of small nerve fibers and small vessel damage, which may represent further warning signs for early diagnosis of ATTRwt.
Collapse
Affiliation(s)
- Luisa Frizziero
- Department of Neuroscience-Ophthalmology Unit, University of Padova, Padova, Italy
| | | | - Eleonora Cosmo
- Department of Neuroscience-Ophthalmology Unit, University of Padova, Padova, Italy
| | - Alberto Cipriani
- Department of Cardio-Thoraco-Vascular Sciences and Public Health, Cardiology Unit, University of Padova, Padova, Italy
| | - Edoardo Midena
- Department of Neuroscience-Ophthalmology Unit, University of Padova, Padova, Italy
- IRCCS-Fondazione Bietti, Rome, Italy
| | - Chiara Briani
- Department of Neuroscience-Neurology Unit, University of Padova, Padova, Italy
| |
Collapse
|
4
|
Pernice HF, Hahn K. [Neurological manifestations of ATTR amyloidosis]. INNERE MEDIZIN (HEIDELBERG, GERMANY) 2023; 64:848-854. [PMID: 37555967 DOI: 10.1007/s00108-023-01570-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/17/2023] [Indexed: 08/10/2023]
Abstract
Transthyretin amyloidosis (ATTR) is a rare disease in which the protein transthyretin (TTR) is deposited in the form of amyloid fibrils in various tissues and organs and secondarily leads to functional impairment, especially in peripheral nerves and the heart. A differentiation is made between hereditary and sporadic forms. The hereditary variant is inherited in an autosomal dominant manner and usually occurs in the younger to middle-aged, while the sporadic form occurs in older age and has no known genetic cause. Typical signs of hereditary ATTR amyloidosis (ATTRv, v for variant) include a rapidly progressing sensorimotor and autonomic polyneuropathy (PNP), cardiac dysfunction as well as ocular and gastrointestinal symptoms. A carpal tunnel syndrome often precedes the manifestation. Various options (tafamidis, patisiran, inotersen or vutrisiran) are available for the treatment of patients with ATTRv with PNP in Germany, depending on the severity. In the sporadic variant of wild-type ATTR amyloidosis (ATTRwt), symptoms of progressive cardiomyopathy are usually prominent; however, neurological assessment of these patients often also reveals a concomitant sensory ataxic PNP. The tetramer stabilizer tafamidis can be used for treatment. Because of this complex presentation, the management of patients with ATTR amyloidosis should be performed in interdisciplinary centers specialized in amyloidosis.
Collapse
Affiliation(s)
- Helena F Pernice
- Amyloidosis Center Charité Berlin (ACCB), Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Deutschland
- Klinik für Neurologie mit Experimenteller Neurologie, Charité - Universitätsmedizin Berlin, Berlin, Deutschland
| | - Katrin Hahn
- Amyloidosis Center Charité Berlin (ACCB), Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117, Berlin, Deutschland.
- Klinik für Neurologie mit Experimenteller Neurologie, Charité - Universitätsmedizin Berlin, Berlin, Deutschland.
- Berlin Institute of Health at Charité (BIH), Universitätsmedizin Berlin, Berlin, Deutschland.
| |
Collapse
|
5
|
Beck G, Yonenobu Y, Kawai M, Ikenaka K, Sera F, Ozono T, Shimada Y, Yamashita R, Sakata Y, Morii E, Yoshinaga T, Ando Y, Murayama S, Mochizuki H. RNA interference in late-stage hereditary transthyretin amyloidosis: a clinicopathological study. J Neurol 2023; 270:4544-4548. [PMID: 37154892 DOI: 10.1007/s00415-023-11754-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 04/28/2023] [Accepted: 04/29/2023] [Indexed: 05/10/2023]
Affiliation(s)
- Goichi Beck
- Department of Neurology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, , Suita City, Osaka, 565-0871, Japan.
| | - Yuki Yonenobu
- Department of Neurology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, , Suita City, Osaka, 565-0871, Japan
| | - Makiko Kawai
- Department of Pathology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Kensuke Ikenaka
- Department of Neurology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, , Suita City, Osaka, 565-0871, Japan
| | - Fusako Sera
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Japan
| | - Tatsuhiko Ozono
- Department of Neurology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, , Suita City, Osaka, 565-0871, Japan
| | - Yuki Shimada
- Department of Neurology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, , Suita City, Osaka, 565-0871, Japan
| | - Rika Yamashita
- Department of Neurology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, , Suita City, Osaka, 565-0871, Japan
| | - Yasushi Sakata
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Japan
| | - Eiichi Morii
- Department of Pathology, Osaka University Graduate School of Medicine, Suita, Japan
| | - Tsuneaki Yoshinaga
- Department of Neurology and Rheumatology, Shinshu University School of Medicine, Matsumoto, Japan
| | - Yukio Ando
- Department of Amyloidosis Research, Faculty of Pharmaceutical Sciences, Nagasaki International University, Sasebo, Japan
| | - Shigeo Murayama
- Department of Neurology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, , Suita City, Osaka, 565-0871, Japan
- Brain Bank for Neurodevelopmental, Molecular Research Center for Children's Mental Development, United Graduate School of Child Development, Neurological and Psychiatric Disorders, Osaka University, Suita, Japan
- Department of Neurology and Neuropathology (the Brain Bank for Aging Research), Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan
| | - Hideki Mochizuki
- Department of Neurology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, , Suita City, Osaka, 565-0871, Japan.
| |
Collapse
|
6
|
Sethi Y, Mahtani AU, Khehra N, Padda I, Patel N, Sebastian SA, Malhi G, Kaiwan O, Saith S, Johal G. Gene Editing as the Future of Cardiac Amyloidosis Therapeutics. Curr Probl Cardiol 2023; 48:101741. [PMID: 37059345 DOI: 10.1016/j.cpcardiol.2023.101741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 04/07/2023] [Indexed: 04/16/2023]
Abstract
BACKGROUND AND SIGNIFICANCE Cardiac Amyloidosis (CA) is a manifestation of a systemic disorder resulting from the deposition of the transthyretin (TTR) in the myocardium, resulting in a myriad manifestations ranging from conduction defects to heart failure. Several proteins, many of which have a genetic predisposition, are responsible for its presentation. Clustered Regularly Interspaced Short Palindromic Repeats of genetic information-Cas9 endonuclease (CRISPR-Cas9) is a RNA-guided endonuclease, which can be targeted using an RNA guide to 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. OBSERVATIONS Previously 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 transthyretin cardiac amyloidosis (ATTR-CA): TTR stabilizers, such as tafamidis and AG10, and RNA interference (siRNA), such as patisiran and vutrisiran. Recently, gene editing has demonstrated some early clinical promise as an emerging therapeutic modality in the treatment of CA. CONCLUSIONS AND RELEVANCE In an introductory gene editing human trial involving 12 subjects with TTR amyloidosis and amyloid cardiomyopathy (ATTR-CM), CRISPR-Cas9 therapy has demonstrated a reduction of 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 cardiac amyloidosis.
Collapse
Affiliation(s)
- Yashendra Sethi
- PearResearch, Dehradun, India; Government Doon Medical College, Dehradun, Uttarakhand, India.
| | - Arun Umesh Mahtani
- Richmond University Medical Center/Mount Sinai, Staten Island, New York, USA.
| | - Nimrat Khehra
- PearResearch, Dehradun, India; Saint James School of Medicine, St Vincent & Grenadines
| | - Inderbir Padda
- Richmond University Medical Center/Mount Sinai, Staten Island, New York, USA
| | - Neil Patel
- PearResearch, Dehradun, India; G.M.E.R.S. Medical College, Himmatnagar, Gujarat, India
| | | | - Gurnaaz Malhi
- Caribbean Medical University School of Medicine, Curacao, Willemstad
| | | | - Sunil Saith
- SUNY Downstate Medical Center, Brooklyn, New York, USA
| | - Gurpreet Johal
- University of Washington, Valley Medical Center, Seattle, Washington, USA
| |
Collapse
|
7
|
Echaniz-Laguna A, Cauquil C, Labeyrie C, Adams D. Treating hereditary transthyretin amyloidosis: Present & future challenges. Rev Neurol (Paris) 2023; 179:30-34. [PMID: 36150937 DOI: 10.1016/j.neurol.2022.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 07/11/2022] [Accepted: 07/12/2022] [Indexed: 02/07/2023]
Abstract
Hereditary transthyretin amyloidosis (ATTRv) is a rare, lethal, autosomal dominant adult-onset genetic gain-of function (GOF) disorder provoked by mutations in the TTR gene. Until recently, therapeutic options were limited and consisted mainly in liver transplantation and TTR-stabilizers. In the last few years, ATTRv has been at the center of major therapeutic breakthroughs, including development of effective small interfering RNA (siRNA) and antisense oligonucleotide (ASO) treatments targeting liver TTR mRNA. Both siRNA (patisiran) and ASO (inotersen) treatments are now commercially available and have dramatically improved ATTRv neurological outcome. Ongoing clinical trials currently evaluate another siRNA, vutrisiran and a novel ASO formulation, eplontersen. A CRISPR-Cas9-based TTR gene editing treatment is also currently evaluated, with encouraging preliminary results. These recent therapeutic developments demonstrate the shifting paradigm of ATTRv, a previously untreatable and lethal disorder and provide a proof-of-concept for developing siRNA, ASO and CRISPR-Cas9 treatments for other GOF genetic disorders.
Collapse
Affiliation(s)
- A Echaniz-Laguna
- Neurology Department, APHP, CHU de Bicêtre, 78, rue du Général Leclerc, 94275 Le Kremlin-Bicêtre cedex, France; French National Reference Center for Rare Neuropathies (NNERF), 94275 Le Kremlin-Bicêtre, France; INSERM U1195, Paris-Saclay University, 94276 Le Kremlin-Bicêtre, France.
| | - C Cauquil
- Neurology Department, APHP, CHU de Bicêtre, 78, rue du Général Leclerc, 94275 Le Kremlin-Bicêtre cedex, France; French National Reference Center for Rare Neuropathies (NNERF), 94275 Le Kremlin-Bicêtre, France
| | - C Labeyrie
- Neurology Department, APHP, CHU de Bicêtre, 78, rue du Général Leclerc, 94275 Le Kremlin-Bicêtre cedex, France; French National Reference Center for Rare Neuropathies (NNERF), 94275 Le Kremlin-Bicêtre, France
| | - D Adams
- Neurology Department, APHP, CHU de Bicêtre, 78, rue du Général Leclerc, 94275 Le Kremlin-Bicêtre cedex, France; French National Reference Center for Rare Neuropathies (NNERF), 94275 Le Kremlin-Bicêtre, France; INSERM U1195, Paris-Saclay University, 94276 Le Kremlin-Bicêtre, France
| |
Collapse
|
8
|
Brannagan TH, Berk JL, Gillmore JD, Maurer MS, Waddington‐Cruz M, Fontana M, Masri A, Obici L, Brambatti M, Baker BF, Hannan LA, Buchele G, Viney NJ, Coelho T, Nativi‐Nicolau J. Liver-directed drugs for transthyretin-mediated amyloidosis. J Peripher Nerv Syst 2022; 27:228-237. [PMID: 36345805 PMCID: PMC10100204 DOI: 10.1111/jns.12519] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 10/28/2022] [Accepted: 10/30/2022] [Indexed: 11/11/2022]
Abstract
Transthyretin-mediated amyloidosis (ATTR) is a rare, under-recognized, progressively debilitating, fatal disease caused by the aggregation and extracellular deposition of amyloid transthyretin (TTR) fibrils in multiple organs and tissues throughout the body. TTR is predominantly synthesized by the liver and normally circulates as a homotetramer, while misfolded monomers aggregate to form amyloid fibrils. One strategy to treat ATTR amyloidosis is to reduce the amount of TTR produced by the liver using drugs that directly target the TTR mRNA or gene. This narrative review focuses on how TTR gene silencing tools act to reduce TTR production, describing strategies for improved targeted delivery of these agents to hepatocytes where TTR is preferentially expressed. Antisense oligonucleotides (ASOs) and small interfering RNAs (siRNAs), termed RNA silencers, cause selective degradation of TTR mRNA, while a TTR gene editing tool reduces TTR expression by introducing nonsense mutations into the TTR gene. Two strategies to facilitate tissue-specific delivery of these nucleic acid-based drugs employ endogenous receptors expressed by hepatocytes. Lipid nanoparticles (LNPs) that recruit apolipoprotein E support low-density lipoprotein receptor-mediated uptake of unconjugated siRNA and are now used for CRISPR gene editing tools. Additionally, conjugating N-acetylgalactosamine (GalNAc) moieties to ASOs or siRNAs facilitates receptor-mediated uptake by the asialoglycoprotein receptor. In summary, ATTR is a progressive disease with various clinical manifestations due to TTR aggregation, deposition, and amyloid formation. Receptor-targeted ligands (eg, GalNAc) and nanoparticle encapsulation (eg, LNPs) are technologies to deliver ASOs, siRNAs, and gene editing tools to hepatocytes, the primary location of TTR synthesis.
Collapse
Affiliation(s)
- Thomas H. Brannagan
- Peripheral Neuropathy CenterColumbia University, Vagelos College of Physicians and SurgeonsNew YorkNew YorkUSA
| | - John L. Berk
- Amyloidosis CenterBoston University School of MedicineBostonMassachusettsUSA
| | - Julian D. Gillmore
- National Amyloidosis CentreUniversity College London, Royal Free HospitalLondonUK
| | - Mathew S. Maurer
- Cardiac Amyloidosis Program, Division of CardiologyColumbia College of Physicians and SurgeonsNew YorkNew YorkUSA
| | - Márcia Waddington‐Cruz
- National Amyloidosis Referral Center‐CEPARMUniversity HospitalFederal University of Rio de JaneiroRio de JaneiroBrazil
| | - Marianna Fontana
- National Amyloidosis CentreUniversity College London, Royal Free HospitalLondonUK
| | - Ahmad Masri
- Cardiac Amyloidosis Program, Knight Cardiovascular InstituteOregon Health & Science UniversityPortlandOregonUSA
| | - Laura Obici
- Amyloidosis Research and Treatment CenterIRCCS Fondazione Policlinico San MatteoPaviaItaly
| | | | | | | | | | | | - Teresa Coelho
- Department of NeurosciencesCentro Hospitalar Universitário do PortoPortoPortugal
| | | |
Collapse
|
9
|
Treatment of Transthyretin Amyloid Cardiomyopathy: The Current Options, the Future, and the Challenges. J Clin Med 2022; 11:jcm11082148. [PMID: 35456241 PMCID: PMC9031576 DOI: 10.3390/jcm11082148] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/07/2022] [Accepted: 04/08/2022] [Indexed: 12/13/2022] Open
Abstract
Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressively debilitating, rare disease associated with high mortality. ATTR-CM occurs when TTR amyloid protein builds up in the myocardium along with different organs, most commonly the peripheral and the autonomic nervous systems. Managing the cardiac complications with standard heart failure medications is difficult due to the challenge to maintain a balance between the high filling pressure associated with restricted ventricular volume and the low cardiac output. To date, tafamidis is the only agent approved for ATTR-CM treatment. Besides, several agents, including green tea, tolcapone, and diflunisal, are used off-label in ATTR-CM patients. Novel therapies using RNA interference also offer clinical promise. Patisiran and inotersen are currently approved for ATTR-polyneuropathy of hereditary origin and are under investigation for ATTR-CM. Monoclonal antibodies in the early development phases carry hope for amyloid deposit clearance. Despite several drug candidates in the clinical development pipeline, the small ATTR-CM patient population raises several challenges. This review describes current and future therapies for ATTR-CM and sheds light on the clinical development hurdles facing them.
Collapse
|