This item was originally published on our sister site, Freethink.
Researchers at the University of Pennsylvania reversed a genetic form of blindness in one patient using a single cure of antisense oligonucleotides, OMICS clinical reports.
The therapy, which targets the mutant RNA, was injected into the patient’s eyes a year ago as part of a trial treating Leber’s congenital amaurosis (ACL). LCA primarily affects the retina, leaving people with severely impaired vision from birth, according to the NIH.
The trial, which took place at the Scheie Eye Institute at Penn’s Perelman School of Medicine, focused on the use of antisense oligonucleotide therapy to treat ACL patients with one of the mutations the most common of the disease.
Antisense oligonucleotide therapy works by altering RNA, the messenger that carries instructions from your DNA to make proteins.
An article in Nature Neurology Reviews describes antisense oligonucleotides as “short, synthetic, single stranded” molecules, which can alter RNA to cause reduction, enhancement or modification of protein creation.
In the Penn study, the targeted protein was created by the mutated LCA gene.
The team, led by Professors Artur V. Cideciyan and Samuel G. Jacobson, injected an antisense oligonucleotide (called sepofarsen) into the eyes of 11 patients.
In a previous study, according to Clinical OMICS, the team had shown that administering the therapy every three months increased the amount of appropriate protein levels in the eyes of 10 patients, thereby improving their sight during the day.
But it is the experience of the eleventh patient that is the subject of their new article, published in Natural medicine.
This eleventh patient chose to receive only one course of sepofarsen and refused the additional doses.
The patient suffered from poor visual acuity, reduced fields of vision and zero night vision, reports Clinical OMICS, but after an injection the patient showed remarkable improvement over the next 15 months – similar to people who have had several, regular injections.
“Our results set a new standard for the biological improvements possible with antisense oligonucleotide therapy in ACL caused by CEP290 mutations,” Cideciyan told Clinical OMICS.
Interestingly, the effects of the shot had a delayed onset; While improvement was seen after one month, the gains peaked about three months later, the authors write. This slow absorption was unexpected and may provide insight into the treatment of other diseases that impact the cilia of retinal cells (that is, those tiny vibrating hairs), the physical cause of ACL.
Antisense oligonucleotide therapy can be effective because the tiny molecules can slide inside the nucleus of the cell, but are not swept away too quickly, so they can stay until the job is done.
The success of the therapy and the unexpected success of a single injection inspire further clinical trials.
“This work represents a truly exciting direction for antisense RNA therapy.”
SAMUEL G. JACOBSON
“There is now, at least in the ocular field, a series of clinical trials using antisense oligonucleotides for various genetic defects caused by the success of the work on ACV associated with CEP290 by Drs Cideciyan and Jacobson”, Joan O’Brien , president of ophthalmology and director of the Scheie Eye Institute, told Clinical OMICS.
Multiple antisense therapies have already been approved by the FDA, particularly for neurological conditions, and have been shown to be effective in the treatment of spinal muscular atrophy and Duchenne muscular dystrophy. Through Genetic Neurology, antisense oligonucleotide therapy trials are currently under development for Huntington’s disease, Parkinson’s disease, and Alzheimer’s disease, among others.
And now add genetic blindness to that list.
“This work represents a really exciting direction for antisense RNA therapy. It has been 30 years since there have been new drugs using antisense RNA oligonucleotides,” Jacobson told Clinical OMICS, “although everyone realized that these treatments were very promising.”