OBJECTIVES: To understand the relationship between the clinical stages of the rare, inherited retinal disorder X-linked retinitis pigmentosa (XLRP) associated with RPGR and the real-world humanistic impact on patients and caregivers.

METHODS: The exploratory, multicentre, non-interventional EXPLORE XLRP-2 study of patients and caregivers combined a retrospective chart review (to collect clinical/demographic data, including XLRP clinical stage [mild, moderate, severe]) with cross-sectional surveys (validated and modified patient- and caregiver-reported outcomes and a sponsor-developed questionnaire).

RESULTS: 176 patients from 10 countries (Austria, Finland, France, Germany, Ireland, Israel, Italy, the Netherlands, Spain, United Kingdom) with XLRP caused by RPGR were enrolled; 169 patients were included in the analyses (81% male; mean age: 39.3 years [SD: 17.6 years]), including 20 adolescents aged 12–17 years. Nyctalopia/night blindness (56%) was the most reported initial XLRP symptom. More severe clinical stage was significantly correlated (p≤0.05) with worse outcomes on most of the patient survey scores, including modified Low Luminance Questionnaire (mLLQ) subscales among adults and some mLLQ subscales among adolescents; Work Productivity & Activity Impairment (WPAI) absenteeism, presenteeism, productivity loss, and activity impairment domains; Patient Global Impression of Mobility and Daily Activity scores; Hospital Anxiety and Depression Scale (HADS) depression score; and sponsor-developed questions (e.g. greater reliance on caregiver support, impacts on career/group activities/financial situation, more healthcare visits, increased support from social services). Among caregivers (n=69; 88% female), mean hours/week spent caregiving was 29 [SD: 35]; caregivers reported high overall well-being (EQ-5D-5L, HADS, and Caregiver Well-Being Scale scores). 55% of adult patients and 72% of caregivers reported being employed.

CONCLUSIONS: This first real-world study to assess the humanistic and quality-of-life impacts of XLRP demonstrates important individual, societal, and healthcare resource use impacts, are more likely to be greater in patients with more severe disease. Caregivers also experience a substantial humanistic impact, particularly when caring for patients with moderate/severe XLRP.