Choroideremia is an incurable, X-linked, recessive retinal dystrophy caused by loss of function mutations in the CHM gene. It is estimated to affect approximately 1 in 50,000 male patients. It is characterized by progressive degeneration of the retinal pigment epithelium, choroid, and photoreceptors, resulting in visual impairment and blindness. There is an unmet need in choroideremia, because currently, there are no approved treatments available for patients with the disease.
We review the patient journey, societal impact, and emerging treatments for patients with choroideremia.
Its relative rarity and similarities with other retinal diseases in early years mean that diagnosis of choroideremia can often be delayed. Furthermore, its impact on affected individuals, and wider society, is also likely underestimated. AAV2-mediated gene therapy is an investigational treatment that aims to replace the faulty CHM gene. Early-phase studies reported potentially important visual acuity gains and maintenance of vision in some patients, and a large Phase 3 program is now underway.
Choroideremia is a disease with a significant unmet need. Interventions that can treat progression of the disease and improve visual and functional outcomes have the potential to reduce health care costs and enhance patient quality of life.
Choroideremia is an incurable, X-linked, recessive retinal dystrophy resulting from mutations in the CHM gene, which encodes for REP1. It is characterized by progressive degeneration of the retinal pigment epithelium, choroid, and photoreceptors resulting in visual impairment and blindness. The authors review the patient journey, societal impact, and emerging treatment strategies.
*Casey Eye Institute, Oregon Health & Science University, Portland, Oregon;
†Retina Foundation of the Southwest, Dallas, Texas;
‡Department of Ophthalmology, University of California, San Francisco, California;
§Department of Ophthalmology, Perelman School of Medicine, Center for Advanced Retinal and Ocular Therapeutics, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania; and
¶Nightstar Therapeutics, London, United Kingdom.
Reprint requests: Mark E. Pennesi, MD, PhD, Casey Eye Institute, Oregon Health & Science University, 3375 SW Terwilliger Boulevard, Portland, OR 97239; e-mail: email@example.com
M. E. Pennesi is a consultant for AGTC, Astellas, Biogen, Editas, FFB, Gensight, Horama, Ionis, Nacuity, Nightstar Therapeutics, Ophthotech, ProQR Therapeutics, RegenexBio, Sanofi, and Spark Therapeutics and has received clinical trial support from AGTC and Nightstar Therapeutics. D. G. Birch is a consultant for Acucela, AGTC, Editas, Genentech, Ionis, Nacuity, and Nightstar Therapeutics and has received clinical trial support from AGTC, Nightstar, Ionis, and 4D Therapeutics and grant support from the Foundation Fighting Blindness. J. L. Duncan is a consultant for AGTC, California Institute for Regenerative Medicine, Editas Medicine, Inc, Foundation Fighting Blindness, ProQR Therapeutics, Inc, Sparing Vision, and Spark Therapeutics. She has received material support for research from Neurotech USA, Inc, and clinical trial support from Second Sight Medical Products, Inc, and Nightstar Therapeutics; she receives grant support from the Foundation Fighting Blindness, the National Eye Institute, and the Food and Drug Administration Office of Orphan Product Development. J. Bennett is a founder of GenSight Biologics, Spark Therapeutics, and Limelight Bio, participates in Clinical Trial Agreements with Spark Therapeutics, and receives funding from Foundation Fighting Blindness and Biogen. A. Girach is an employee of Nightstar Therapeutics. Editorial support was provided by Clemence Hindley, PhD, of Fishawack Communications and funded by Nightstar Therapeutics.