Introduction Erythropoietic protoporphyria (EPP) is a rare, inherited disorder caused by accumulation of a toxic metabolite, protoporphyrin IX (PPIX), which can lead to severe, painful phototoxicity and potential liver disease. EPP can have significant impacts on health-related quality of life (HRQoL) and healthcare resource utilization (HRU). To date, little has been published on the burden of EPP from the patient perspective.

Objective A cross. sectional, online survey study is currently underway with adolescents (12–17 years of age) and adults (> 18 years of age) with EPP and X-linked protoporphyria (collectively, EPP) that seeks to describe the burden associated with EPP in terms of symptoms, HRQoL, HRU as well as preferences for treatment.

Methods Participants, recruited by an advocacy group, are > 12 years of age, report a diagnosis of EPP, reside in North America, are able to speak, read and write English, and able to complete a one-time online questionnaire.

The online questionnaire, which could take up to 60 minutes to complete, includes existing validated and newly developed patient-reported outcome (PRO) measures to assess HRQoL, including the EPP Impact Questionnaire (EPIQ), items assessing early warning symptoms and pain from the Sunlight Exposure Diary, PROMIS Satisfaction with Social Roles and Activities-8a, PROMIS Peer Relationships-8a (adolescents only), PROMIS Social Isolation-4a, and original items assessing physical functioning, anxiety, depression, fatigue, bullying/unfair treatment, work/school loss/productivity, and need for accommodations when doing daily activities. Original items were also developed to assess the EPP diagnostic journey and HRU, including hospitalizations, emergency room visits, physician visits, and prescription and over-the-counter medication use. The questionnaire also includes items assessing preference for various types of EPP treatment. The questionnaire was developed based on qualitative research conducted with individuals with EPP, in collaboration with EPP clinical experts, a patient advocacy group, and PRO research experts.

All participants are required to provide informed consent (adults) or assent and parental permission (adolescents). Each participant will be remunerated for their time.

Results The study has been approved by an institutional review board (WCG IRB), and was initiated in May 2024. Enrollment is currently ongoing. The plan is to enroll a minimum of 100 adults and 25 adolescents. Preliminary data will be presented at this meeting.

Conclusion Currently, there is a lack of available data describing the burden of EPP from the perspective of the patient. Results from this study will provide comprehensive insight regarding the HRQoL and HRU impact on the lives of adolescents and adults with EPP in North America.