Retinitis Pigmentosa Research Advances
Recent developments in research on retinitis pigmintosa.
FDA Approves Spark’s Vision-Restoring Gene Therapy
Spark Therapeutics’ vision-restoring RPE65 gene therapy has received marketing approval from the U.S. Food and Drug Administration, becoming the first gene therapy to gain regulatory approval in the U.S. for the eye or any inherited condition. Known as LUXTURNA™ (voretigene neparvovec), the gene therapy restored vision in a clinical trial for people between the ages of 4 and 44 with Leber congenital amaurosis (LCA) caused by mutations in the gene RPE65. Study participants with severe vision loss reported putting away their navigational canes, seeing stars, being able to read, and recognizing faces of loved ones. Vision restoration has persisted for at least three years. The treatment is also designed to work for people with retinitis pigmentosa (RP) caused by RPE65 mutations. FFB invested about $10 million in more than a decade of lab research that made possible the RPE65 gene therapy clinical trial at the Children’s Hospital of Philadelphia (CHOP).
jCyte Stem-Cell Therapy Moving into Phase 3 Clinical Trial for RP
The stem-cell therapy company jCyte reported promising results for its 85-participant Phase 2b clinical trial of its therapy for people with retinitis pigmentosa (RP). The company plans to launch a Phase 3 trial for the treatment in 2021. The treatment involves intravitreal injection of retinal progenitor cells (RPCs), which are stem cells that have partially developed into the retinal cells that make vision possible. Based on lab studies, researchers believe the treatment can preserve and potentially rescue the patient’s existing photoreceptors, thereby saving and possibly restoring vision. Administration of the treatment does not require surgery and can be performed in minutes in an outpatient setting. The RPCs are injected into the vitreous, the gel-like substance in the middle of the eye.
ReNeuron’s Stem-Cell Therapy Performs Encouragingly in Phase 2 Clinical Trial
ReNeuron, a stem-cell development company in the United Kingdom, has reported that three patients with retinitis pigmentosa (RP) have been treated with its stem-cell therapy in its Phase 2 clinical trial taking place at Massachusetts Eye and Ear Infirmary (MEEI). All have shown vision improvements shortly after treatment. The treatment involves the injection of human retinal progenitor cells (hRPCs) — stem cells that have partially developed into photoreceptors — underneath the patient’s retina. Based on results from preclinical studies, researchers believe the injected hRPCs will integrate into the retina and fully develop into photoreceptors, replacing those lost to disease, thereby restoring vision. FFB funded previous research that made this trial possible.
Three Companies Are Conducting Clinical Trials for Their Optogenetic Therapies for Advanced RP
GenSight, Bionic Sight, and Nanoscope have each launched clinical trials for their optogenetic therapies for RP and potentially other retinal diseases. The treatments are designed to provide vision to people who are completely blind from conditions such as retinitis pigmentosa and Usher syndrome. The therapy works by bestowing light sensitivity to ganglion cells in patients who have lost all of their photoreceptors. Both Bionic Sight and GenSight have reported some modest restored vision in their early stage trials. Nanoscope reported vision improvements for their early stage trial in India. Nanoscope now has a Phase 2 trial underway in the US.
AGTC, Janssen/MeiraGTx, and Biogen Conducting XLRP Gene Therapy Clinical Trials
Three companies are each conducting XLRP (RPGR) gene therapy clinical trials. Biogen is in a Phase 2/3 trial. AGTC and MeiraGTx are planning Phase 3 trials. All of the companies have reported vision improvements (retinal sensitivity and/or visual acuity) for patients in their Phase 1/2 trials. However, Biogen didn’t meet their endpoints for their Phase 2/3 trial.
Coave Conducting Gene Therapy Clinical Trial for RP (PDE6B Mutations)
The French biotech Coave is conducting a Phase 1/2 gene therapy clinical trial for people with retinitis pigmentosa (RP) caused by PDE6B mutations. The three-year trials taking place at University Hospital of Nantes in France will enroll a total of 12 patients.
Nacuity Launches Clinical Trial for Oral Antioxidant Therapy
Dallas-based Nacuity has launched a Phase 1/2 clinical trial in Australia for its oral antioxidant therapy. The Foundation Fighting Blindness is investing up to $7.5 million to advance the promising, emerging drug for retinitis pigmentosa, Usher syndrome, and related conditions. Known as N-acetylcysteine-amide (NACA), the molecule is designed to slow vision loss by protecting retinal cells from oxidative stress. In previous Foundation-funded lab studies at Johns Hopkins University, NACA slowed retinal degeneration in rodent models of RP.
SparingVision Plans Clinical Trial to Evaluate Sight-Saving Protein for RP
A spin-off of the Institut de la Vision, SparingVision was established to clinically develop and commercialize a protein known as rod-derived cone-viability factor (RdCVF). The emerging therapy performed well in several previous lab studies funded by the Foundation Fighting Blindness. Scientists demonstrated that RdCVF prevented or slowed the degeneration of cones, the cells in the retina that provide central and color vision and enable people to read, drive, and recognize faces. RdCVF is naturally secreted by rods, the retinal cells that provide night and peripheral vision. A clinical trial for the emerging therapy is planned
ProQR Conducting Clinical Trial of Antisense Oligonucleotide for RHO-P23H Mutation
ProQR, a developer of RNA therapies in the Netherlands, has announced that the first patient in its Aurora Phase 1/2 clinical trial has received QR-1123, the company’s emerging therapy for autosomal dominant retinitis pigmentosa (adRP) caused by the P23H mutation in the gene RHO. The variant is the most prevalent variant causing adRP in the US, affecting approximately 2,500 people. The study, which plans to enroll 35 participants, is taking place at the Retina Foundation of the Southwest in Dallas, Texas, and VitreoRetinal Associates in Gainesville, Florida.