The goal of this clinical trial is to learn if NPI-001 works to prevent progression of retinitis pigmentosa in adults diagnosed with Usher syndrome. It will also provide information about the safety of NPI-001. The main questions it aims to answer are:
Does NPI-001 slow down the loss of photoreceptors? What medical problems do participants have when taking NPI-001? Researchers will compare NPI-001 to a placebo (a look-alike substance that contains no drug) to see if NPI-001 works to preserve vision.
Participants will:
Take NPI-001 or a placebo twice a day, every day for 24 months Visit the clinic 9 times for checkups and tests
Able to comprehend and willing to sign an informed consent form (ICF) and to adhere to the study protocol.
Diagnosed with Usher syndrome.
EZ zone width ≥ 500 microns, which includes the fovea in each eye at Visit 1 (Screening).
All edges of the EZ area in both eyes can be visualized at Visit 1 (Screening).
Concurrent retinal pathologies that result in vision loss or inability to fixate, including but not limited to, choroideremia, retinal vein occlusion, and neovascular age-related macular degeneration.
Intraocular surgery within the last two months or capsulotomy within the last month.
Current or history of uveitis, Coat's disease, diabetic retinopathy, glaucoma, herpes simplex of the eye, or currently has a cataract that prevents visualization of the posterior pole.
Likely to require cataract surgery within the next 12 months.