A Study Comparing Two Doses of AGTC-501 in Male Subjects With X-linked Retinitis Pigmentosa Caused by RPGR Mutations (SKYLINE)

Inclusion Criteria: * Provide written informed consent or assent (per local regulation), prior to the conduct of any study-related procedure. Subjects who provide assent must have a parent, guardian, or legal representative provide written informed consent. * Be between 8 and 50 years of age (inclusive) at the time of informed consent and assent (as applicable). * Be male and have at least one documented pathogenic or likely pathogenic variant in the RPGR gene * Have a clinical diagnosis of XLRP. * Have a BCVA no better than 75 letters and no worse than 35 letters based on an ETDRS chart at each screening visit. * Be able to perform all tests of visual and retinal function and structure in both eyes based on the subject's reliability, and fixation, per the investigator's discretion. * Have detectable baseline mean macular sensitivity measured by (MAIA) microperimetry, as determined by the investigator and confirmed by the Central Reading Center (CRC). * Have detectable EZ line in both eyes as assessed by SD-OCT and confirmed by the CRC. Exclusion Criteria: * Have other known disease-causing mutations documented in the subject's medical history or identified through a retinal dystrophy gene panel, that in the opinion of the investigator would interfere with the potential therapeutic effect of the study agent or the quality of the assessments. * For subjects with herpes simplex virus (HSV): 1. Have history of oral or genital herpes and unable and/or unwilling to utilize prophylactic antiviral medication. 2. Have a history of ocular herpes. 3. Have active oral or genital herpes or are currently receiving treatment for HSV infection. * Have complicating systemic diseases (e.g., medical conditions causing immunosuppression, active systemic infection) that would preclude the gene transfer or ocular surgery. * Have known sensitivity or allergy to systemic corticosteroids or other immunosuppressive medications. * Have used anti-coagulant agents that may alter coagulation * Have received any vaccination/immunization within 28 days prior to screening and/or during screening with the exception of the influenza vaccine, which is only exclusionary if they have received the influenza vaccine within 28 days prior to randomization. * Have used systemic corticosteroids or other immunosuppressive medications within 3 months prior to screening and/or intend to use during screening. * Have previously received any AAV gene therapy product, stem cell therapy, cell-based therapy, or similar biologics. Ocular Exclusion Criteria (Either Eye): * Have pre-existing eye conditions that would preclude the planned surgery, interfere with the interpretation of study endpoints, or increase the risk of surgical complications * Have significant media opacity impacting evaluation of the retina or vitreous. * Had intraocular surgery within 90 days of study treatment administration. * Have any active ocular/intraocular infection or inflammation * Have a history of steroid-induced raised IOP of \>25 mmHg following corticosteroid exposure, despite topical IOP-lowering pharmacologic therapy. * Have any artificial retinal implant or prosthesis. * Have absence of clear ocular media and/or inadequate pupil dilation to facilitate good quality OCT images. * Have any history of rhegmatogenous retinal detachment. * Have myopia (spherical equivalent) exceeding -10 diopters (or axial length of \>30 mm if PI deems it appropriate to measure) or presence of pathologic myopia in the study eye. * Have passed the Low Contrast Ora-VNC™ mobility course in either eye or binocularly at any screening visit.