Real-world assessment of the patient profile, clinical characteristics, treatment patterns, and outcomes associated with erythropoietic and X-linked protoporphyria

Abstract

Erythropoietic protoporphyria (EPP) and X-linked protoporphyria (XLP) are rare genetic disorders. There are limited data regarding how these disorders are managed in real-world settings. The aim of this study was to document the characteristics and treatment patterns among patients diagnosed with EPP or XLP in general real-world settings in the United States. We, therefore, conducted a retrospective medical record review of patients diagnosed with EPP or XLP on or before July 1, 2020. Data were analyzed for patients with EPP (n = 299) and XLP (n = 91). Outcomes included demographic and clinical characteristics, diagnostic testing, therapy recommendations, office visits, emergency department visits, and hospitalizations. Costs were assigned to healthcare resources. Mean (standard deviation [SD]; median) time between the first symptom documented in the medical records and diagnosis was 2.9 (5.1; 1.3) years. The most common pre-diagnostic tests were liver function, total plasma and erythrocyte protoporphyrin, genetic tests, and renal function. Patients were advised to use sunscreen (85%) or modify their lifestyle (83%). Within 12 months of diagnosis, the mean (SD; median) number of office visits, emergency department visits, and inpatient hospitalizations related to EPP or XLP were 4.0 (3.5; 3.0), 0.8 (1.6; 0), and 0.4 (1.3; 0), respectively. Patients with EPP or XLP have several unmet needs, including timely and accurate diagnosis, symptom relief, and efficacious prevention of phototoxic reactions.