Nanoscope Zooms in on Retinitis Pigmentosa and Stargardt Disease at ASRS
Dallas-based Nanoscope Therapeutics announced that it will be making two presentations at the 2022 Annual Scientific Meeting of the American Society of Retina Specialists (ASRS) in New York City this week. The focus is on its gene therapy programs to treat degenerative retinal diseases, specifically retinitis pigmentosa and Stargardt disease.
Retinitis pigmentosa (RP) is a family of rare eyes disease that affects the retina, the light-sensitive tissue at the back of the eye. RP causes the cells in the retina to break down slowly over time, which leads to vision loss.
Nanoscope will provide an update on the U.S. clinical trials of its gene therapy, MCO-010, for RP. The therapy uses an intraocular injection to deliver a gene that encodes for the ambient light-sensitive MCO protein into retinal cells.
MCO-101 is also being developed for Stargardt disease, which is one of the most common types of inherited macular degeneration. It affects approximately 30,000 people in the U.S and results in progressive degeneration of the macula, causing dark spots in the central field of vision.
Phase II Retinitis Pigmentosa Data Due Early 2023
MCO-010 is currently in Phase IIb trials in the U.S. for RP with topline data expected in the first quarter of 2023. Nanoscope announced in February that it had completed enrollment in this trial with a total of 27 patients with severe vision loss caused by the disease. The Phase I/IIa trial of the gene therapy in 11 patients with RP demonstrated the therapy was well-tolerated and improved quality of life associated with significant functional vision improvement.
“Completing enrollment for this trial is another important milestone for Nanoscope and millions suffering from retinal diseases for which there are no effective treatments,” Sulagna Bhattacharya, chief executive officer of Nanoscope said in a February statement. “Positive results from this trial will bring us closer to meeting this significant unmet medical need.”
The company also has a Phase II study of MCO-010 in Stargardt patients. The therapy has received orphan drug designations for both RP and Stargardt from the U.S. Food and Drug Administration.
Ocular Gene Therapy Space Exploding
Inherited diseases of the eye are amenable to gene therapy, in part because the therapies can be directly introduced into the eye, rather than systemically, like for other diseases. For example, the first gene therapy to be approved in the U.S. was Spark Therapeutics’ Luxturna (voretigene neparvovec) for a rare, genetic type of blindness. It was approved for the treatment of pediatric and adult patients with confirmed biallelic RPE65 mutation-associated retinal dystrophy in December 2017.
Gene therapies continue to be investigated for many diseases of the eye. In January 2021, a preclinical study on mice using gene therapy was run by the National Eye Institute and Harvard Medical School. This unusual technique involved a virus vector to introduce a few genes dubbed Yamanaka factors that can reprogram the DNA of mature cells to transform them into pluripotent stem cells. The technique repaired damage to retinal ganglion cells, a type of neuron at the back of the eye. The same techniques also appeared to protect some optic nerve cells from damage and stimulated others to grow fresh connections to the brain. And yet another experiment reversed some vision damage in a mouse model of glaucoma, a disease related to intraocular pressure in the eye that is a leading cause of age-related blindness in humans.
And in June 2021, researchers with the University of Basel and the University of Pennsylvania Medical Center (UPMC) utilized technology from GenSight Biologics to test a gene therapy for RP in the PIONEER I/IIa trial. The research group isolated a gene from a light-sensing species of green algae and introduced it into a patient’s eyes. The gene then encoded a photoactivatable protein known as ChrimsonR.