Avidity Biosciences, Inc., a biopharmaceutical company, engages in the delivery of RNA therapeutics. It develops antibody oligonucleotide conjugates (AOC) that are designed to treat diseases previously untreatable with RNA therapeutics. The company's lead product candidate AOC 1001 for the treatment of myotonic dystrophy type 1, a rare monogenic muscle disease that is in phase 1/2 clinical trial. Its other products in pipeline include AOC 1044 for the treatment of duchenne muscular dystrophy, which is under phase 1/2 clinical development trial; and AOC 1020 to treat facioscapulohumeral muscular dystrophy that is in phase 1/2 clinical trial. The company is developing products for rare skeletal muscle and rare cardiac diseases. Avidity Biosciences, Inc. was incorporated in 2012 and is headquartered in San Diego, California.

PTC Therapeutics, Inc., a biopharmaceutical company, focuses on the discovery, development, and commercialization of medicines to patients with rare disorders in the United States and internationally. The company offers Translarna and Emflaza for the treatment of Duchenne muscular dystrophy; Upstaza to treat aromatic l-amino acid decarboxylas (AADC) deficiency, a central nervous system disorder; Tegsedi and Waylivra for the treatment of rare diseases; and Evrysdi to treat spinal muscular atrophy (SMA) in adults and children. Its development pipeline products include Sepiapterin for the treatment of phenylketonuria; PTC518 splicing platform, which is being developed for the treatment of Huntington's disease; and ferroptosis and inflammation platforms, including vatiquinone to treat Friedreich ataxia and utreloxastat for the treatment of amyotrophic lateral sclerosis. The company distributes its products through third-party distributors. It has collaborations with F. Hoffman-La Roche Ltd, Hoffman-La Roche Inc., the SMA Foundation, National Taiwan University, Akcea Therapeutics, Inc., and Shiratori Pharmaceutical Co., Ltd. The company has license and collaboration agreement with Novartis Pharmaceuticals Corporation to develop PTC518 Huntington's disease program. PTC Therapeutics, Inc. was incorporated in 1998 and is headquartered in South Plainfield, New Jersey.

Dyne Therapeutics, Inc., a clinical-stage muscle disease company, operates as a biotechnology company that focuses on advancing therapeutics for genetically driven muscle diseases in the United States. It is developing a portfolio of muscle disease therapeutics, including programs in myotonic dystrophy type 1; duchenne muscular dystrophy; and facioscapulohumeral dystrophy, as well as rare skeletal muscle, and cardiac and metabolic muscle diseases using its FORCE platform that delivers disease-modifying therapeutics. Dyne Therapeutics, Inc. was incorporated in 2017 and is headquartered in Waltham, Massachusetts.

Fulcrum Therapeutics, Inc., a clinical-stage biopharmaceutical company, focuses on developing products for improving the lives of patients with genetically defined diseases in the areas of high unmet medical need in the United States. Its product candidates are losmapimod, a small molecule for the treatment of facioscapulohumeral muscular dystrophy is under phase III clinical trial; and pociredir, a fetal hemoglobin inducer for the treatment of sickle cell disease and beta-thalassemia is under phase I clinical trial. The company is also discovering drug targets for the treatments of rare neuromuscular, muscular, central nervous system, and hematologic disorders, as well as cardiomyopathies and pulmonary diseases. It has collaboration and license agreement with Acceleron Pharma Inc. to identify biological targets to modulate specific pathways associated with a targeted indication within the pulmonary disease space; MyoKardia, Inc. to discover and develop therapies for the treatment of genetic cardiomyopathies; and Sanofi for the development and commercialization of losmapimod, an oral small molecule being investigated for the treatment of facioscapulohumeral muscular dystrophy. Fulcrum Therapeutics, Inc. was Incorporated in 2015 and is headquartered in Cambridge, Massachusetts.

4D Molecular Therapeutics, Inc., a clinical-stage biotherapeutics company, develops genetic medicines using its therapeutic vector evolution platform in the Netherland and the United States. The company develops a portfolio of genetic medicine product candidates focuses in three therapeutic areas for ophthalmology, cardiology, and pulmonology. Its product pipeline includes 4D-150, which is in phase 1/2 clinical trial for the treatment of wet age-related macular degeneration; and is in phase 1/2 clinical trial for the treatment of diabetic macular edema. The company develops 4D-125, which is in phase 1/2 clinical trial for the treatment of x-linked retinitis pigmentosa; 4D-110, which is in phase 1/2 clinical trial for the treatment of choroideremia; 4D-710, which is in phase 1/2 clinical trial for the treatment cystic fibrosis lung disease; and 4D-310 to treat fabry disease cardiomyopathy and is in phase 1/2 clinical trial. In addition, its product candidates comprises 4D-175, which is in pre-clinical development for the treatment for geographic trophy; and 4D-725 to treat alpha-1 antitrypsin deficiency lung disease and is in pre-clinical development. The company has collaboration and licensing agreements with Arbor Biotechnologies, Inc.; Astellas Gene Therapies, Inc; uniQure biopharma B.V.; and Cystic Fibrosis Foundation. 4D Molecular Therapeutics, Inc. was founded in 2013 and is headquartered in Emeryville, California.

Solid Biosciences Inc., a life science company, develops therapies for neuromuscular and cardiac diseases in the United States. The company's lead product candidate is SGT-003, a gene transfer candidate for the treatment of Duchenne muscular dystrophy; and SGT-501 to treat Catecholaminergic polymorphic ventricular tachycardia. It is also developing AVB-401 for the treatment of BAG3-mediated dilated cardiomyopathy; SGT-601 to treat a rare cardiac disease characterized by mutations in the gene that codes for cardiac troponin T protein, which helps coordinate contraction of the heart muscle; SGT-701 for treatment of rare inherited disease characterized by mutations in the RBM20 gene, a cardiac splicing factor that regulates alternative splicing, and codes for RNA binding motif protein 20; and AVB-202-TT to treat Friedreich's ataxia, as well as other drugs for the treatment of cardiac and other diseases. In addition, the company is involved in developing platform technologies, including capsid libraries and dual gene expression, a technology for packaging multiple transgenes into one capsid. The company has collaboration and license agreement with Ultragenyx Pharmaceutical Inc. to develop and commercialize new gene therapies for Duchenne; and a license agreement with the University of Washington, University of Missouri, and University of Florida. Solid Biosciences Inc. was incorporated in 2013 and is headquartered in Charlestown, Massachusetts.

Lexeo Therapeutics, Inc. operates as a clinical stage genetic medicine company that focuses on hereditary and acquired diseases. The company develops LX2006, which is an AAVrh10-based gene therapy candidate for the treatment of Friedreich's ataxia (FA) cardiomyopathy; LX2020, an AAVrh10-based gene therapy candidate for the treatment of plakophilin-2 arrhythmogenic cardiomyopathy; LX2021, a gene therapy candidate for the treatment of DSP cardiomyopathy associated with it; and LX2022, a gene therapy candidate for the treatment of hypertrophic cardiomyopathy, or HCM caused by TNNI3 gene. It also develops LX1001, an AAVrh10-based gene therapy candidate for the treatment of APOE4 homozygous; LX1020, a gene therapy candidate for the treatment of APOE4 homozygous; LX1021 for the treatment of APOE4 homozygotes; and LX1004 for the treatment of CLN2 Batten disease. The company was incorporated in 2017 and is based in New York, New York.

Tenaya Therapeutics, Inc., a biotechnology company, discovers, develops, and delivers therapies for heart disease in the United States. It develops its products through gene editing, cellular regeneration, and gene addition. The company is developing TN-201, a gene therapy for myosin binding protein C3-associated hypertrophic cardiomyopathy which is in phase 1 clinical trial; TN-301, a small molecule for heart failure with preserved ejection fraction which is in phase 1 clinical trial; and TN-401, a gene therapy for plakophilin 2-associated arrhythmogenic right ventricular cardiomyopathy which is in preclinical stage. It also develops an adeno-associated virus-based gene therapy designed to deliver the dworf gene for patient with dilated cardiomyopathy; and reprogramming program for heart failure due to prior myocardial infarction. Tenaya Therapeutics, Inc. was incorporated in 2016 and is headquartered in South San Francisco, California.