Article
Author: Minnick, Pansy ; Georgiadis, Anastasios ; Fleck, Penny R ; Kumaran, Neruban ; Tee, James J L ; Smith, Alexander J ; Bainbridge, James ; Michaelides, Michel ; Kalitzeos, Angelos ; Xu, Jialin ; Georgiou, Michalis ; Yang, Yesa ; DE Guimaraes, Thales A C ; Besirli, Cagri G ; Ali, Robin R ; Comander, Jason I ; Huckfeldt, Rachel M ; Ripamonti, Caterina ; Shah, Syed Mahmood ; Wong, Peggy ; Forbes, Alexandria ; Fung, Albert ; Peluso, Colleen ; Anglade, Eddy ; Naylor, Stuart ; Wong, Sui Chien ; Sahel, José-Alain ; Zeldin, Robert ; Clark, Michael
PURPOSE:To assess the safety and efficacy of AAV5-hRKp.RPGR in participants with retinitis pigmentosa GTPase regulator (RPGR)-associated X-linked retinitis pigmentosa (XLRP).
DESIGN:Open-label, phase 1/2 dose escalation/expansion study (ClinicalTrials.gov Identifier: NCT03252847).
METHODS:Males (≥5 years old) with XLRP-RPGR were evaluated. In the dose escalation phase, subretinal AAV5-hRKp.RPGR (low: 1.0 × 1011 vg/ml; intermediate: 2.0 × 1011 vg/ml; high: 4.0 × 1011 vg/ml) was administered to the poorer-seeing eye (n = 10). Dose confirmation (intermediate dose) was carried out in 3 pediatric participants. In the dose expansion phase, 36 participants were randomized 1:1:1 to immediate (low or intermediate dose) or deferred (control) treatment. The primary outcome was safety. Secondary efficacy outcomes included static perimetry, microperimetry, vision-guided mobility, best corrected visual acuity, and contrast sensitivity. Safety and efficacy outcomes were assessed for 52 weeks for immediate treatment participants and 26 weeks for control participants.
RESULTS:AAV5-hRKp.RPGR was safe and well tolerated, with no reported dose-limiting events. Most adverse events (AEs) were transient and related to the surgical procedure, resolving without intervention. Two serious AEs were reported with immediate treatment (retinal detachment, uveitis). A third serious AE (increased intraocular pressure) was reported outside the reporting period. All ocular inflammation-related AEs responded to corticosteroids. Treatment with AAV5-hRKp.RPGR resulted in improvements in retinal sensitivity and functional vision compared with the deferred group at Week 26; similar trends were observed at Week 52.
CONCLUSIONS:AAV5-hRKp.RPGR demonstrated an anticipated and manageable AE profile through 52 weeks. Safety and efficacy findings support investigation in a phase 3 trial.