Project 467148

Retinitis pigmentosa (RP) is a devastating and irreversible disease that affects 1 in 3500 individuals and is characterized by progressive night blindness, and constriction and loss of the visual field. While the exact triggers that lead from mutation to disease remain to be elucidated, a large body of literature suggest that apoptotic death of the cells in the retina contributes to disease progression. We have studied the X-linked inhibitor of apoptosis (XIAP) as a therapy for the treatment of RP. We will conduct a retrospective cohort study to develop optimal eligibility criteria that remain feasible and will enhance our ability to recruit the number of patients required for a Phase I clinical trial to evaluate XIAP's efficacy in preventing RP progression. In order to optimize our chances for detecting disease progression within a relatively short timeline (2-3 years following initiation of a clinical trial), we will identify patients that have had multiple structural and functional tests over the past 5 years, have been followed on an annual or biannual basic, and have shown measurable annual (or biannual) declines in vision based on visual field testing, electroretinograms (ERGs) and/or optical coherence tomography (OCT). Demographic and clinical data will be assessed to optimize eligibility criteria. While this study is primarily aimed at developing optical eligibility criteria, the methods can also serve as the groundwork for identifying potential patients for the trial. With the review of the patient population proposed here and partnership with Fighting Blindness Canada and their patient registry, we will be in an ideal position to identify and enroll RP patients into a Phase I clinical trial following Health Canada approval of our therapy.