Burden of illness and unmet needs in patients with erythropoietic protoporphyria and X-linked protoporphyria: A large US nationwide claims analysis.

Background: Erythropoietic protoporphyria (EPP) and X-linked protoporphyria (XLP) are rare genetic disorders caused by the accumulation of the toxic metabolite protoporphyrin IX, which results in painful phototoxicity upon sunlight exposure. Despite their significant impact on quality of life and potential for serious complications, treatment options for EPP/XLP are limited and real-world burden of illness and unmet needs have been understudied in this population.

Objective: To retrospectively evaluate real-world health care resource utilization (HRU) and costs among patients with EPP/XLP compared with matched comparators and to characterize the current EPP/XLP management in the United States using a large, nationwide claims database.

Methods: Data were obtained from the Komodo Research Database (2016-2023). Patients with EPP/XLP (≥2 EPP/XLP diagnosis codes, first diagnosis defined index date) and comparator patients without an EPP/XLP diagnosis were identified and matched at a 1:4 ratio on index date and key characteristics. Patients were required to have ≥6 months of continuous enrollment pre-index (baseline period). HRU and costs were assessed post-index on a per patient per year (PPPY) basis. Comparison between cohorts were conducted using rate ratios (RRs) estimated from negative binomial regressions and cost ratios estimated from 2-part linear models, respectively. The use of treatments for EPP/XLP and concomitant medications commonly prescribed for associated comorbidities was also assessed during the follow-up period.

Results: In total, 696 patients with EPP/XLP and 2,784 matched comparator patients were included. In both cohorts, mean age was approximately 45.5 years; 55% were female and 55% were White. Over a mean follow-up of 30 months, patients with EPP/XLP had significantly higher all-cause HRU compared with comparators, with a mean PPPY number of inpatient stays of 0.8 vs 0.2 (RR = 3.4; P < 0.001), emergency department visits of 1.5 vs 0.9 (RR = 1.7; P = 0.002), and outpatient visits of 35.2 vs 17.5 (RR = 2.0; P < 0.001). All-cause costs were also significantly higher among patients with EPP/XLP compared with comparators with a mean PPPY total cost of $71,714 vs $18,646 (ratio = 3.9; P < 0.001), driven by inpatient costs (mean = $30,909 vs $6,318; ratio = 4.9; P < 0.001) and outpatient costs (mean = $33,416 vs $7,573; ratio = 4.4; P < 0.001). Although only 7.6% of patients with EPP/XLP received treatment for EPP/XLP, most commonly afamelanotide (3.9%), most (68.4%) used medication related to EPP/XLP-associated comorbidities, including narcotics (46.3%), nonsteroidal anti-inflammatory drugs (38.2%), and antidepressants (35.1%).

Conclusions: Patients with EPP/XLP experienced substantially higher HRU and costs compared with matched comparators, yet few received EPP/XLP-specific treatment. This highlights the need for new effective and accessible treatments that could improve patient outcomes and alleviate the broader disease burden.